1 /*
   2  * Copyright (c) 2003, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #ifndef _WINDOWS
  27 #include "alloca.h"
  28 #endif
  29 #include "asm/macroAssembler.hpp"
  30 #include "asm/macroAssembler.inline.hpp"
  31 #include "code/debugInfoRec.hpp"
  32 #include "code/icBuffer.hpp"
  33 #include "code/nativeInst.hpp"
  34 #include "code/vtableStubs.hpp"
  35 #include "gc/shared/collectedHeap.hpp"
  36 #include "gc/shared/gcLocker.hpp"
  37 #include "gc/shared/barrierSet.hpp"
  38 #include "gc/shared/barrierSetAssembler.hpp"
  39 #include "interpreter/interpreter.hpp"
  40 #include "logging/log.hpp"
  41 #include "memory/resourceArea.hpp"
  42 #include "memory/universe.hpp"
  43 #include "oops/compiledICHolder.hpp"
  44 #include "runtime/safepointMechanism.hpp"
  45 #include "runtime/sharedRuntime.hpp"
  46 #include "runtime/vframeArray.hpp"
  47 #include "utilities/align.hpp"
  48 #include "utilities/formatBuffer.hpp"
  49 #include "vm_version_x86.hpp"
  50 #include "vmreg_x86.inline.hpp"
  51 #ifdef COMPILER1
  52 #include "c1/c1_Runtime1.hpp"
  53 #endif
  54 #ifdef COMPILER2
  55 #include "opto/runtime.hpp"
  56 #endif
  57 #if INCLUDE_JVMCI
  58 #include "jvmci/jvmciJavaClasses.hpp"
  59 #endif
  60 
  61 #define __ masm->
  62 
  63 const int StackAlignmentInSlots = StackAlignmentInBytes / VMRegImpl::stack_slot_size;
  64 
  65 class SimpleRuntimeFrame {
  66 
  67   public:
  68 
  69   // Most of the runtime stubs have this simple frame layout.
  70   // This class exists to make the layout shared in one place.
  71   // Offsets are for compiler stack slots, which are jints.
  72   enum layout {
  73     // The frame sender code expects that rbp will be in the "natural" place and
  74     // will override any oopMap setting for it. We must therefore force the layout
  75     // so that it agrees with the frame sender code.
  76     rbp_off = frame::arg_reg_save_area_bytes/BytesPerInt,
  77     rbp_off2,
  78     return_off, return_off2,
  79     framesize
  80   };
  81 };
  82 
  83 class RegisterSaver {
  84   // Capture info about frame layout.  Layout offsets are in jint
  85   // units because compiler frame slots are jints.
  86 #define XSAVE_AREA_BEGIN 160
  87 #define XSAVE_AREA_YMM_BEGIN 576
  88 #define XSAVE_AREA_ZMM_BEGIN 1152
  89 #define XSAVE_AREA_UPPERBANK 1664
  90 #define DEF_XMM_OFFS(regnum) xmm ## regnum ## _off = xmm_off + (regnum)*16/BytesPerInt, xmm ## regnum ## H_off
  91 #define DEF_YMM_OFFS(regnum) ymm ## regnum ## _off = ymm_off + (regnum)*16/BytesPerInt, ymm ## regnum ## H_off
  92 #define DEF_ZMM_OFFS(regnum) zmm ## regnum ## _off = zmm_off + (regnum-16)*64/BytesPerInt, zmm ## regnum ## H_off
  93   enum layout {
  94     fpu_state_off = frame::arg_reg_save_area_bytes/BytesPerInt, // fxsave save area
  95     xmm_off       = fpu_state_off + XSAVE_AREA_BEGIN/BytesPerInt,            // offset in fxsave save area
  96     DEF_XMM_OFFS(0),
  97     DEF_XMM_OFFS(1),
  98     // 2..15 are implied in range usage
  99     ymm_off = xmm_off + (XSAVE_AREA_YMM_BEGIN - XSAVE_AREA_BEGIN)/BytesPerInt,
 100     DEF_YMM_OFFS(0),
 101     DEF_YMM_OFFS(1),
 102     // 2..15 are implied in range usage
 103     zmm_high = xmm_off + (XSAVE_AREA_ZMM_BEGIN - XSAVE_AREA_BEGIN)/BytesPerInt,
 104     zmm_off = xmm_off + (XSAVE_AREA_UPPERBANK - XSAVE_AREA_BEGIN)/BytesPerInt,
 105     DEF_ZMM_OFFS(16),
 106     DEF_ZMM_OFFS(17),
 107     // 18..31 are implied in range usage
 108     fpu_state_end = fpu_state_off + ((FPUStateSizeInWords-1)*wordSize / BytesPerInt),
 109     fpu_stateH_end,
 110     r15_off, r15H_off,
 111     r14_off, r14H_off,
 112     r13_off, r13H_off,
 113     r12_off, r12H_off,
 114     r11_off, r11H_off,
 115     r10_off, r10H_off,
 116     r9_off,  r9H_off,
 117     r8_off,  r8H_off,
 118     rdi_off, rdiH_off,
 119     rsi_off, rsiH_off,
 120     ignore_off, ignoreH_off,  // extra copy of rbp
 121     rsp_off, rspH_off,
 122     rbx_off, rbxH_off,
 123     rdx_off, rdxH_off,
 124     rcx_off, rcxH_off,
 125     rax_off, raxH_off,
 126     // 16-byte stack alignment fill word: see MacroAssembler::push/pop_IU_state
 127     align_off, alignH_off,
 128     flags_off, flagsH_off,
 129     // The frame sender code expects that rbp will be in the "natural" place and
 130     // will override any oopMap setting for it. We must therefore force the layout
 131     // so that it agrees with the frame sender code.
 132     rbp_off, rbpH_off,        // copy of rbp we will restore
 133     return_off, returnH_off,  // slot for return address
 134     reg_save_size             // size in compiler stack slots
 135   };
 136 
 137  public:
 138   static OopMap* save_live_registers(MacroAssembler* masm, int additional_frame_words, int* total_frame_words, bool save_vectors = false);
 139   static void restore_live_registers(MacroAssembler* masm, bool restore_vectors = false);
 140 
 141   // Offsets into the register save area
 142   // Used by deoptimization when it is managing result register
 143   // values on its own
 144 
 145   static int rax_offset_in_bytes(void)    { return BytesPerInt * rax_off; }
 146   static int rdx_offset_in_bytes(void)    { return BytesPerInt * rdx_off; }
 147   static int rbx_offset_in_bytes(void)    { return BytesPerInt * rbx_off; }
 148   static int xmm0_offset_in_bytes(void)   { return BytesPerInt * xmm0_off; }
 149   static int return_offset_in_bytes(void) { return BytesPerInt * return_off; }
 150 
 151   // During deoptimization only the result registers need to be restored,
 152   // all the other values have already been extracted.
 153   static void restore_result_registers(MacroAssembler* masm);
 154 };
 155 
 156 OopMap* RegisterSaver::save_live_registers(MacroAssembler* masm, int additional_frame_words, int* total_frame_words, bool save_vectors) {
 157   int off = 0;
 158   int num_xmm_regs = XMMRegisterImpl::number_of_registers;
 159   if (UseAVX < 3) {
 160     num_xmm_regs = num_xmm_regs/2;
 161   }
 162 #if COMPILER2_OR_JVMCI
 163   if (save_vectors) {
 164     assert(UseAVX > 0, "Vectors larger than 16 byte long are supported only with AVX");
 165     assert(MaxVectorSize <= 64, "Only up to 64 byte long vectors are supported");
 166   }
 167 #else
 168   assert(!save_vectors, "vectors are generated only by C2 and JVMCI");
 169 #endif
 170 
 171   // Always make the frame size 16-byte aligned, both vector and non vector stacks are always allocated
 172   int frame_size_in_bytes = align_up(reg_save_size*BytesPerInt, num_xmm_regs);
 173   // OopMap frame size is in compiler stack slots (jint's) not bytes or words
 174   int frame_size_in_slots = frame_size_in_bytes / BytesPerInt;
 175   // CodeBlob frame size is in words.
 176   int frame_size_in_words = frame_size_in_bytes / wordSize;
 177   *total_frame_words = frame_size_in_words;
 178 
 179   // Save registers, fpu state, and flags.
 180   // We assume caller has already pushed the return address onto the
 181   // stack, so rsp is 8-byte aligned here.
 182   // We push rpb twice in this sequence because we want the real rbp
 183   // to be under the return like a normal enter.
 184 
 185   __ enter();          // rsp becomes 16-byte aligned here
 186   __ push_CPU_state(); // Push a multiple of 16 bytes
 187 
 188   // push cpu state handles this on EVEX enabled targets
 189   if (save_vectors) {
 190     // Save upper half of YMM registers(0..15)
 191     int base_addr = XSAVE_AREA_YMM_BEGIN;
 192     for (int n = 0; n < 16; n++) {
 193       __ vextractf128_high(Address(rsp, base_addr+n*16), as_XMMRegister(n));
 194     }
 195     if (VM_Version::supports_evex()) {
 196       // Save upper half of ZMM registers(0..15)
 197       base_addr = XSAVE_AREA_ZMM_BEGIN;
 198       for (int n = 0; n < 16; n++) {
 199         __ vextractf64x4_high(Address(rsp, base_addr+n*32), as_XMMRegister(n));
 200       }
 201       // Save full ZMM registers(16..num_xmm_regs)
 202       base_addr = XSAVE_AREA_UPPERBANK;
 203       off = 0;
 204       int vector_len = Assembler::AVX_512bit;
 205       for (int n = 16; n < num_xmm_regs; n++) {
 206         __ evmovdqul(Address(rsp, base_addr+(off++*64)), as_XMMRegister(n), vector_len);
 207       }
 208     }
 209   } else {
 210     if (VM_Version::supports_evex()) {
 211       // Save upper bank of ZMM registers(16..31) for double/float usage
 212       int base_addr = XSAVE_AREA_UPPERBANK;
 213       off = 0;
 214       for (int n = 16; n < num_xmm_regs; n++) {
 215         __ movsd(Address(rsp, base_addr+(off++*64)), as_XMMRegister(n));
 216       }
 217     }
 218   }
 219   __ vzeroupper();
 220   if (frame::arg_reg_save_area_bytes != 0) {
 221     // Allocate argument register save area
 222     __ subptr(rsp, frame::arg_reg_save_area_bytes);
 223   }
 224 
 225   // Set an oopmap for the call site.  This oopmap will map all
 226   // oop-registers and debug-info registers as callee-saved.  This
 227   // will allow deoptimization at this safepoint to find all possible
 228   // debug-info recordings, as well as let GC find all oops.
 229 
 230   OopMapSet *oop_maps = new OopMapSet();
 231   OopMap* map = new OopMap(frame_size_in_slots, 0);
 232 
 233 #define STACK_OFFSET(x) VMRegImpl::stack2reg((x))
 234 
 235   map->set_callee_saved(STACK_OFFSET( rax_off ), rax->as_VMReg());
 236   map->set_callee_saved(STACK_OFFSET( rcx_off ), rcx->as_VMReg());
 237   map->set_callee_saved(STACK_OFFSET( rdx_off ), rdx->as_VMReg());
 238   map->set_callee_saved(STACK_OFFSET( rbx_off ), rbx->as_VMReg());
 239   // rbp location is known implicitly by the frame sender code, needs no oopmap
 240   // and the location where rbp was saved by is ignored
 241   map->set_callee_saved(STACK_OFFSET( rsi_off ), rsi->as_VMReg());
 242   map->set_callee_saved(STACK_OFFSET( rdi_off ), rdi->as_VMReg());
 243   map->set_callee_saved(STACK_OFFSET( r8_off  ), r8->as_VMReg());
 244   map->set_callee_saved(STACK_OFFSET( r9_off  ), r9->as_VMReg());
 245   map->set_callee_saved(STACK_OFFSET( r10_off ), r10->as_VMReg());
 246   map->set_callee_saved(STACK_OFFSET( r11_off ), r11->as_VMReg());
 247   map->set_callee_saved(STACK_OFFSET( r12_off ), r12->as_VMReg());
 248   map->set_callee_saved(STACK_OFFSET( r13_off ), r13->as_VMReg());
 249   map->set_callee_saved(STACK_OFFSET( r14_off ), r14->as_VMReg());
 250   map->set_callee_saved(STACK_OFFSET( r15_off ), r15->as_VMReg());
 251   // For both AVX and EVEX we will use the legacy FXSAVE area for xmm0..xmm15,
 252   // on EVEX enabled targets, we get it included in the xsave area
 253   off = xmm0_off;
 254   int delta = xmm1_off - off;
 255   for (int n = 0; n < 16; n++) {
 256     XMMRegister xmm_name = as_XMMRegister(n);
 257     map->set_callee_saved(STACK_OFFSET(off), xmm_name->as_VMReg());
 258     off += delta;
 259   }
 260   if(UseAVX > 2) {
 261     // Obtain xmm16..xmm31 from the XSAVE area on EVEX enabled targets
 262     off = zmm16_off;
 263     delta = zmm17_off - off;
 264     for (int n = 16; n < num_xmm_regs; n++) {
 265       XMMRegister zmm_name = as_XMMRegister(n);
 266       map->set_callee_saved(STACK_OFFSET(off), zmm_name->as_VMReg());
 267       off += delta;
 268     }
 269   }
 270 
 271 #if COMPILER2_OR_JVMCI
 272   if (save_vectors) {
 273     off = ymm0_off;
 274     int delta = ymm1_off - off;
 275     for (int n = 0; n < 16; n++) {
 276       XMMRegister ymm_name = as_XMMRegister(n);
 277       map->set_callee_saved(STACK_OFFSET(off), ymm_name->as_VMReg()->next(4));
 278       off += delta;
 279     }
 280   }
 281 #endif // COMPILER2_OR_JVMCI
 282 
 283   // %%% These should all be a waste but we'll keep things as they were for now
 284   if (true) {
 285     map->set_callee_saved(STACK_OFFSET( raxH_off ), rax->as_VMReg()->next());
 286     map->set_callee_saved(STACK_OFFSET( rcxH_off ), rcx->as_VMReg()->next());
 287     map->set_callee_saved(STACK_OFFSET( rdxH_off ), rdx->as_VMReg()->next());
 288     map->set_callee_saved(STACK_OFFSET( rbxH_off ), rbx->as_VMReg()->next());
 289     // rbp location is known implicitly by the frame sender code, needs no oopmap
 290     map->set_callee_saved(STACK_OFFSET( rsiH_off ), rsi->as_VMReg()->next());
 291     map->set_callee_saved(STACK_OFFSET( rdiH_off ), rdi->as_VMReg()->next());
 292     map->set_callee_saved(STACK_OFFSET( r8H_off  ), r8->as_VMReg()->next());
 293     map->set_callee_saved(STACK_OFFSET( r9H_off  ), r9->as_VMReg()->next());
 294     map->set_callee_saved(STACK_OFFSET( r10H_off ), r10->as_VMReg()->next());
 295     map->set_callee_saved(STACK_OFFSET( r11H_off ), r11->as_VMReg()->next());
 296     map->set_callee_saved(STACK_OFFSET( r12H_off ), r12->as_VMReg()->next());
 297     map->set_callee_saved(STACK_OFFSET( r13H_off ), r13->as_VMReg()->next());
 298     map->set_callee_saved(STACK_OFFSET( r14H_off ), r14->as_VMReg()->next());
 299     map->set_callee_saved(STACK_OFFSET( r15H_off ), r15->as_VMReg()->next());
 300     // For both AVX and EVEX we will use the legacy FXSAVE area for xmm0..xmm15,
 301     // on EVEX enabled targets, we get it included in the xsave area
 302     off = xmm0H_off;
 303     delta = xmm1H_off - off;
 304     for (int n = 0; n < 16; n++) {
 305       XMMRegister xmm_name = as_XMMRegister(n);
 306       map->set_callee_saved(STACK_OFFSET(off), xmm_name->as_VMReg()->next());
 307       off += delta;
 308     }
 309     if (UseAVX > 2) {
 310       // Obtain xmm16..xmm31 from the XSAVE area on EVEX enabled targets
 311       off = zmm16H_off;
 312       delta = zmm17H_off - off;
 313       for (int n = 16; n < num_xmm_regs; n++) {
 314         XMMRegister zmm_name = as_XMMRegister(n);
 315         map->set_callee_saved(STACK_OFFSET(off), zmm_name->as_VMReg()->next());
 316         off += delta;
 317       }
 318     }
 319   }
 320 
 321   return map;
 322 }
 323 
 324 void RegisterSaver::restore_live_registers(MacroAssembler* masm, bool restore_vectors) {
 325   int num_xmm_regs = XMMRegisterImpl::number_of_registers;
 326   if (UseAVX < 3) {
 327     num_xmm_regs = num_xmm_regs/2;
 328   }
 329   if (frame::arg_reg_save_area_bytes != 0) {
 330     // Pop arg register save area
 331     __ addptr(rsp, frame::arg_reg_save_area_bytes);
 332   }
 333 
 334 #if COMPILER2_OR_JVMCI
 335   if (restore_vectors) {
 336     assert(UseAVX > 0, "Vectors larger than 16 byte long are supported only with AVX");
 337     assert(MaxVectorSize <= 64, "Only up to 64 byte long vectors are supported");
 338   }
 339 #else
 340   assert(!restore_vectors, "vectors are generated only by C2");
 341 #endif
 342 
 343   __ vzeroupper();
 344 
 345   // On EVEX enabled targets everything is handled in pop fpu state
 346   if (restore_vectors) {
 347     // Restore upper half of YMM registers (0..15)
 348     int base_addr = XSAVE_AREA_YMM_BEGIN;
 349     for (int n = 0; n < 16; n++) {
 350       __ vinsertf128_high(as_XMMRegister(n), Address(rsp, base_addr+n*16));
 351     }
 352     if (VM_Version::supports_evex()) {
 353       // Restore upper half of ZMM registers (0..15)
 354       base_addr = XSAVE_AREA_ZMM_BEGIN;
 355       for (int n = 0; n < 16; n++) {
 356         __ vinsertf64x4_high(as_XMMRegister(n), Address(rsp, base_addr+n*32));
 357       }
 358       // Restore full ZMM registers(16..num_xmm_regs)
 359       base_addr = XSAVE_AREA_UPPERBANK;
 360       int vector_len = Assembler::AVX_512bit;
 361       int off = 0;
 362       for (int n = 16; n < num_xmm_regs; n++) {
 363         __ evmovdqul(as_XMMRegister(n), Address(rsp, base_addr+(off++*64)), vector_len);
 364       }
 365     }
 366   } else {
 367     if (VM_Version::supports_evex()) {
 368       // Restore upper bank of ZMM registers(16..31) for double/float usage
 369       int base_addr = XSAVE_AREA_UPPERBANK;
 370       int off = 0;
 371       for (int n = 16; n < num_xmm_regs; n++) {
 372         __ movsd(as_XMMRegister(n), Address(rsp, base_addr+(off++*64)));
 373       }
 374     }
 375   }
 376 
 377   // Recover CPU state
 378   __ pop_CPU_state();
 379   // Get the rbp described implicitly by the calling convention (no oopMap)
 380   __ pop(rbp);
 381 }
 382 
 383 void RegisterSaver::restore_result_registers(MacroAssembler* masm) {
 384 
 385   // Just restore result register. Only used by deoptimization. By
 386   // now any callee save register that needs to be restored to a c2
 387   // caller of the deoptee has been extracted into the vframeArray
 388   // and will be stuffed into the c2i adapter we create for later
 389   // restoration so only result registers need to be restored here.
 390 
 391   // Restore fp result register
 392   __ movdbl(xmm0, Address(rsp, xmm0_offset_in_bytes()));
 393   // Restore integer result register
 394   __ movptr(rax, Address(rsp, rax_offset_in_bytes()));
 395   __ movptr(rdx, Address(rsp, rdx_offset_in_bytes()));
 396 
 397   // Pop all of the register save are off the stack except the return address
 398   __ addptr(rsp, return_offset_in_bytes());
 399 }
 400 
 401 // Is vector's size (in bytes) bigger than a size saved by default?
 402 // 16 bytes XMM registers are saved by default using fxsave/fxrstor instructions.
 403 bool SharedRuntime::is_wide_vector(int size) {
 404   return size > 16;
 405 }
 406 
 407 size_t SharedRuntime::trampoline_size() {
 408   return 16;
 409 }
 410 
 411 void SharedRuntime::generate_trampoline(MacroAssembler *masm, address destination) {
 412   __ jump(RuntimeAddress(destination));
 413 }
 414 
 415 // The java_calling_convention describes stack locations as ideal slots on
 416 // a frame with no abi restrictions. Since we must observe abi restrictions
 417 // (like the placement of the register window) the slots must be biased by
 418 // the following value.
 419 static int reg2offset_in(VMReg r) {
 420   // Account for saved rbp and return address
 421   // This should really be in_preserve_stack_slots
 422   return (r->reg2stack() + 4) * VMRegImpl::stack_slot_size;
 423 }
 424 
 425 static int reg2offset_out(VMReg r) {
 426   return (r->reg2stack() + SharedRuntime::out_preserve_stack_slots()) * VMRegImpl::stack_slot_size;
 427 }
 428 
 429 // ---------------------------------------------------------------------------
 430 // Read the array of BasicTypes from a signature, and compute where the
 431 // arguments should go.  Values in the VMRegPair regs array refer to 4-byte
 432 // quantities.  Values less than VMRegImpl::stack0 are registers, those above
 433 // refer to 4-byte stack slots.  All stack slots are based off of the stack pointer
 434 // as framesizes are fixed.
 435 // VMRegImpl::stack0 refers to the first slot 0(sp).
 436 // and VMRegImpl::stack0+1 refers to the memory word 4-byes higher.  Register
 437 // up to RegisterImpl::number_of_registers) are the 64-bit
 438 // integer registers.
 439 
 440 // Note: the INPUTS in sig_bt are in units of Java argument words, which are
 441 // either 32-bit or 64-bit depending on the build.  The OUTPUTS are in 32-bit
 442 // units regardless of build. Of course for i486 there is no 64 bit build
 443 
 444 // The Java calling convention is a "shifted" version of the C ABI.
 445 // By skipping the first C ABI register we can call non-static jni methods
 446 // with small numbers of arguments without having to shuffle the arguments
 447 // at all. Since we control the java ABI we ought to at least get some
 448 // advantage out of it.
 449 
 450 int SharedRuntime::java_calling_convention(const BasicType *sig_bt,
 451                                            VMRegPair *regs,
 452                                            int total_args_passed,
 453                                            int is_outgoing) {
 454 
 455   // Create the mapping between argument positions and
 456   // registers.
 457   static const Register INT_ArgReg[Argument::n_int_register_parameters_j] = {
 458     j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5
 459   };
 460   static const XMMRegister FP_ArgReg[Argument::n_float_register_parameters_j] = {
 461     j_farg0, j_farg1, j_farg2, j_farg3,
 462     j_farg4, j_farg5, j_farg6, j_farg7
 463   };
 464 
 465 
 466   uint int_args = 0;
 467   uint fp_args = 0;
 468   uint stk_args = 0; // inc by 2 each time
 469 
 470   for (int i = 0; i < total_args_passed; i++) {
 471     switch (sig_bt[i]) {
 472     case T_BOOLEAN:
 473     case T_CHAR:
 474     case T_BYTE:
 475     case T_SHORT:
 476     case T_INT:
 477       if (int_args < Argument::n_int_register_parameters_j) {
 478         regs[i].set1(INT_ArgReg[int_args++]->as_VMReg());
 479       } else {
 480         regs[i].set1(VMRegImpl::stack2reg(stk_args));
 481         stk_args += 2;
 482       }
 483       break;
 484     case T_VOID:
 485       // halves of T_LONG or T_DOUBLE
 486       assert(i != 0 && (sig_bt[i - 1] == T_LONG || sig_bt[i - 1] == T_DOUBLE), "expecting half");
 487       regs[i].set_bad();
 488       break;
 489     case T_LONG:
 490       assert((i + 1) < total_args_passed && sig_bt[i + 1] == T_VOID, "expecting half");
 491       // fall through
 492     case T_OBJECT:
 493     case T_ARRAY:
 494     case T_ADDRESS:
 495       if (int_args < Argument::n_int_register_parameters_j) {
 496         regs[i].set2(INT_ArgReg[int_args++]->as_VMReg());
 497       } else {
 498         regs[i].set2(VMRegImpl::stack2reg(stk_args));
 499         stk_args += 2;
 500       }
 501       break;
 502     case T_FLOAT:
 503       if (fp_args < Argument::n_float_register_parameters_j) {
 504         regs[i].set1(FP_ArgReg[fp_args++]->as_VMReg());
 505       } else {
 506         regs[i].set1(VMRegImpl::stack2reg(stk_args));
 507         stk_args += 2;
 508       }
 509       break;
 510     case T_DOUBLE:
 511       assert((i + 1) < total_args_passed && sig_bt[i + 1] == T_VOID, "expecting half");
 512       if (fp_args < Argument::n_float_register_parameters_j) {
 513         regs[i].set2(FP_ArgReg[fp_args++]->as_VMReg());
 514       } else {
 515         regs[i].set2(VMRegImpl::stack2reg(stk_args));
 516         stk_args += 2;
 517       }
 518       break;
 519     default:
 520       ShouldNotReachHere();
 521       break;
 522     }
 523   }
 524 
 525   return align_up(stk_args, 2);
 526 }
 527 
 528 // Patch the callers callsite with entry to compiled code if it exists.
 529 static void patch_callers_callsite(MacroAssembler *masm) {
 530   Label L;
 531   __ cmpptr(Address(rbx, in_bytes(Method::code_offset())), (int32_t)NULL_WORD);
 532   __ jcc(Assembler::equal, L);
 533 
 534   // Save the current stack pointer
 535   __ mov(r13, rsp);
 536   // Schedule the branch target address early.
 537   // Call into the VM to patch the caller, then jump to compiled callee
 538   // rax isn't live so capture return address while we easily can
 539   __ movptr(rax, Address(rsp, 0));
 540 
 541   // align stack so push_CPU_state doesn't fault
 542   __ andptr(rsp, -(StackAlignmentInBytes));
 543   __ push_CPU_state();
 544   __ vzeroupper();
 545   // VM needs caller's callsite
 546   // VM needs target method
 547   // This needs to be a long call since we will relocate this adapter to
 548   // the codeBuffer and it may not reach
 549 
 550   // Allocate argument register save area
 551   if (frame::arg_reg_save_area_bytes != 0) {
 552     __ subptr(rsp, frame::arg_reg_save_area_bytes);
 553   }
 554   __ mov(c_rarg0, rbx);
 555   __ mov(c_rarg1, rax);
 556   __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, SharedRuntime::fixup_callers_callsite)));
 557 
 558   // De-allocate argument register save area
 559   if (frame::arg_reg_save_area_bytes != 0) {
 560     __ addptr(rsp, frame::arg_reg_save_area_bytes);
 561   }
 562 
 563   __ vzeroupper();
 564   __ pop_CPU_state();
 565   // restore sp
 566   __ mov(rsp, r13);
 567   __ bind(L);
 568 }
 569 
 570 
 571 static void gen_c2i_adapter(MacroAssembler *masm,
 572                             int total_args_passed,
 573                             int comp_args_on_stack,
 574                             const BasicType *sig_bt,
 575                             const VMRegPair *regs,
 576                             Label& skip_fixup) {
 577   // Before we get into the guts of the C2I adapter, see if we should be here
 578   // at all.  We've come from compiled code and are attempting to jump to the
 579   // interpreter, which means the caller made a static call to get here
 580   // (vcalls always get a compiled target if there is one).  Check for a
 581   // compiled target.  If there is one, we need to patch the caller's call.
 582   patch_callers_callsite(masm);
 583 
 584   __ bind(skip_fixup);
 585 
 586   // Since all args are passed on the stack, total_args_passed *
 587   // Interpreter::stackElementSize is the space we need. Plus 1 because
 588   // we also account for the return address location since
 589   // we store it first rather than hold it in rax across all the shuffling
 590 
 591   int extraspace = (total_args_passed * Interpreter::stackElementSize) + wordSize;
 592 
 593   // stack is aligned, keep it that way
 594   extraspace = align_up(extraspace, 2*wordSize);
 595 
 596   // Get return address
 597   __ pop(rax);
 598 
 599   // set senderSP value
 600   __ mov(r13, rsp);
 601 
 602   __ subptr(rsp, extraspace);
 603 
 604   // Store the return address in the expected location
 605   __ movptr(Address(rsp, 0), rax);
 606 
 607   // Now write the args into the outgoing interpreter space
 608   for (int i = 0; i < total_args_passed; i++) {
 609     if (sig_bt[i] == T_VOID) {
 610       assert(i > 0 && (sig_bt[i-1] == T_LONG || sig_bt[i-1] == T_DOUBLE), "missing half");
 611       continue;
 612     }
 613 
 614     // offset to start parameters
 615     int st_off   = (total_args_passed - i) * Interpreter::stackElementSize;
 616     int next_off = st_off - Interpreter::stackElementSize;
 617 
 618     // Say 4 args:
 619     // i   st_off
 620     // 0   32 T_LONG
 621     // 1   24 T_VOID
 622     // 2   16 T_OBJECT
 623     // 3    8 T_BOOL
 624     // -    0 return address
 625     //
 626     // However to make thing extra confusing. Because we can fit a long/double in
 627     // a single slot on a 64 bt vm and it would be silly to break them up, the interpreter
 628     // leaves one slot empty and only stores to a single slot. In this case the
 629     // slot that is occupied is the T_VOID slot. See I said it was confusing.
 630 
 631     VMReg r_1 = regs[i].first();
 632     VMReg r_2 = regs[i].second();
 633     if (!r_1->is_valid()) {
 634       assert(!r_2->is_valid(), "");
 635       continue;
 636     }
 637     if (r_1->is_stack()) {
 638       // memory to memory use rax
 639       int ld_off = r_1->reg2stack() * VMRegImpl::stack_slot_size + extraspace;
 640       if (!r_2->is_valid()) {
 641         // sign extend??
 642         __ movl(rax, Address(rsp, ld_off));
 643         __ movptr(Address(rsp, st_off), rax);
 644 
 645       } else {
 646 
 647         __ movq(rax, Address(rsp, ld_off));
 648 
 649         // Two VMREgs|OptoRegs can be T_OBJECT, T_ADDRESS, T_DOUBLE, T_LONG
 650         // T_DOUBLE and T_LONG use two slots in the interpreter
 651         if ( sig_bt[i] == T_LONG || sig_bt[i] == T_DOUBLE) {
 652           // ld_off == LSW, ld_off+wordSize == MSW
 653           // st_off == MSW, next_off == LSW
 654           __ movq(Address(rsp, next_off), rax);
 655 #ifdef ASSERT
 656           // Overwrite the unused slot with known junk
 657           __ mov64(rax, CONST64(0xdeadffffdeadaaaa));
 658           __ movptr(Address(rsp, st_off), rax);
 659 #endif /* ASSERT */
 660         } else {
 661           __ movq(Address(rsp, st_off), rax);
 662         }
 663       }
 664     } else if (r_1->is_Register()) {
 665       Register r = r_1->as_Register();
 666       if (!r_2->is_valid()) {
 667         // must be only an int (or less ) so move only 32bits to slot
 668         // why not sign extend??
 669         __ movl(Address(rsp, st_off), r);
 670       } else {
 671         // Two VMREgs|OptoRegs can be T_OBJECT, T_ADDRESS, T_DOUBLE, T_LONG
 672         // T_DOUBLE and T_LONG use two slots in the interpreter
 673         if ( sig_bt[i] == T_LONG || sig_bt[i] == T_DOUBLE) {
 674           // long/double in gpr
 675 #ifdef ASSERT
 676           // Overwrite the unused slot with known junk
 677           __ mov64(rax, CONST64(0xdeadffffdeadaaab));
 678           __ movptr(Address(rsp, st_off), rax);
 679 #endif /* ASSERT */
 680           __ movq(Address(rsp, next_off), r);
 681         } else {
 682           __ movptr(Address(rsp, st_off), r);
 683         }
 684       }
 685     } else {
 686       assert(r_1->is_XMMRegister(), "");
 687       if (!r_2->is_valid()) {
 688         // only a float use just part of the slot
 689         __ movflt(Address(rsp, st_off), r_1->as_XMMRegister());
 690       } else {
 691 #ifdef ASSERT
 692         // Overwrite the unused slot with known junk
 693         __ mov64(rax, CONST64(0xdeadffffdeadaaac));
 694         __ movptr(Address(rsp, st_off), rax);
 695 #endif /* ASSERT */
 696         __ movdbl(Address(rsp, next_off), r_1->as_XMMRegister());
 697       }
 698     }
 699   }
 700 
 701   // Schedule the branch target address early.
 702   __ movptr(rcx, Address(rbx, in_bytes(Method::interpreter_entry_offset())));
 703   __ jmp(rcx);
 704 }
 705 
 706 static void range_check(MacroAssembler* masm, Register pc_reg, Register temp_reg,
 707                         address code_start, address code_end,
 708                         Label& L_ok) {
 709   Label L_fail;
 710   __ lea(temp_reg, ExternalAddress(code_start));
 711   __ cmpptr(pc_reg, temp_reg);
 712   __ jcc(Assembler::belowEqual, L_fail);
 713   __ lea(temp_reg, ExternalAddress(code_end));
 714   __ cmpptr(pc_reg, temp_reg);
 715   __ jcc(Assembler::below, L_ok);
 716   __ bind(L_fail);
 717 }
 718 
 719 void SharedRuntime::gen_i2c_adapter(MacroAssembler *masm,
 720                                     int total_args_passed,
 721                                     int comp_args_on_stack,
 722                                     const BasicType *sig_bt,
 723                                     const VMRegPair *regs) {
 724 
 725   // Note: r13 contains the senderSP on entry. We must preserve it since
 726   // we may do a i2c -> c2i transition if we lose a race where compiled
 727   // code goes non-entrant while we get args ready.
 728   // In addition we use r13 to locate all the interpreter args as
 729   // we must align the stack to 16 bytes on an i2c entry else we
 730   // lose alignment we expect in all compiled code and register
 731   // save code can segv when fxsave instructions find improperly
 732   // aligned stack pointer.
 733 
 734   // Adapters can be frameless because they do not require the caller
 735   // to perform additional cleanup work, such as correcting the stack pointer.
 736   // An i2c adapter is frameless because the *caller* frame, which is interpreted,
 737   // routinely repairs its own stack pointer (from interpreter_frame_last_sp),
 738   // even if a callee has modified the stack pointer.
 739   // A c2i adapter is frameless because the *callee* frame, which is interpreted,
 740   // routinely repairs its caller's stack pointer (from sender_sp, which is set
 741   // up via the senderSP register).
 742   // In other words, if *either* the caller or callee is interpreted, we can
 743   // get the stack pointer repaired after a call.
 744   // This is why c2i and i2c adapters cannot be indefinitely composed.
 745   // In particular, if a c2i adapter were to somehow call an i2c adapter,
 746   // both caller and callee would be compiled methods, and neither would
 747   // clean up the stack pointer changes performed by the two adapters.
 748   // If this happens, control eventually transfers back to the compiled
 749   // caller, but with an uncorrected stack, causing delayed havoc.
 750 
 751   // Pick up the return address
 752   __ movptr(rax, Address(rsp, 0));
 753 
 754   if (VerifyAdapterCalls &&
 755       (Interpreter::code() != NULL || StubRoutines::code1() != NULL)) {
 756     // So, let's test for cascading c2i/i2c adapters right now.
 757     //  assert(Interpreter::contains($return_addr) ||
 758     //         StubRoutines::contains($return_addr),
 759     //         "i2c adapter must return to an interpreter frame");
 760     __ block_comment("verify_i2c { ");
 761     Label L_ok;
 762     if (Interpreter::code() != NULL)
 763       range_check(masm, rax, r11,
 764                   Interpreter::code()->code_start(), Interpreter::code()->code_end(),
 765                   L_ok);
 766     if (StubRoutines::code1() != NULL)
 767       range_check(masm, rax, r11,
 768                   StubRoutines::code1()->code_begin(), StubRoutines::code1()->code_end(),
 769                   L_ok);
 770     if (StubRoutines::code2() != NULL)
 771       range_check(masm, rax, r11,
 772                   StubRoutines::code2()->code_begin(), StubRoutines::code2()->code_end(),
 773                   L_ok);
 774     const char* msg = "i2c adapter must return to an interpreter frame";
 775     __ block_comment(msg);
 776     __ stop(msg);
 777     __ bind(L_ok);
 778     __ block_comment("} verify_i2ce ");
 779   }
 780 
 781   // Must preserve original SP for loading incoming arguments because
 782   // we need to align the outgoing SP for compiled code.
 783   __ movptr(r11, rsp);
 784 
 785   // Cut-out for having no stack args.  Since up to 2 int/oop args are passed
 786   // in registers, we will occasionally have no stack args.
 787   int comp_words_on_stack = 0;
 788   if (comp_args_on_stack) {
 789     // Sig words on the stack are greater-than VMRegImpl::stack0.  Those in
 790     // registers are below.  By subtracting stack0, we either get a negative
 791     // number (all values in registers) or the maximum stack slot accessed.
 792 
 793     // Convert 4-byte c2 stack slots to words.
 794     comp_words_on_stack = align_up(comp_args_on_stack*VMRegImpl::stack_slot_size, wordSize)>>LogBytesPerWord;
 795     // Round up to miminum stack alignment, in wordSize
 796     comp_words_on_stack = align_up(comp_words_on_stack, 2);
 797     __ subptr(rsp, comp_words_on_stack * wordSize);
 798   }
 799 
 800 
 801   // Ensure compiled code always sees stack at proper alignment
 802   __ andptr(rsp, -16);
 803 
 804   // push the return address and misalign the stack that youngest frame always sees
 805   // as far as the placement of the call instruction
 806   __ push(rax);
 807 
 808   // Put saved SP in another register
 809   const Register saved_sp = rax;
 810   __ movptr(saved_sp, r11);
 811 
 812   // Will jump to the compiled code just as if compiled code was doing it.
 813   // Pre-load the register-jump target early, to schedule it better.
 814   __ movptr(r11, Address(rbx, in_bytes(Method::from_compiled_offset())));
 815 
 816 #if INCLUDE_JVMCI
 817   if (EnableJVMCI || UseAOT) {
 818     // check if this call should be routed towards a specific entry point
 819     __ cmpptr(Address(r15_thread, in_bytes(JavaThread::jvmci_alternate_call_target_offset())), 0);
 820     Label no_alternative_target;
 821     __ jcc(Assembler::equal, no_alternative_target);
 822     __ movptr(r11, Address(r15_thread, in_bytes(JavaThread::jvmci_alternate_call_target_offset())));
 823     __ movptr(Address(r15_thread, in_bytes(JavaThread::jvmci_alternate_call_target_offset())), 0);
 824     __ bind(no_alternative_target);
 825   }
 826 #endif // INCLUDE_JVMCI
 827 
 828   // Now generate the shuffle code.  Pick up all register args and move the
 829   // rest through the floating point stack top.
 830   for (int i = 0; i < total_args_passed; i++) {
 831     if (sig_bt[i] == T_VOID) {
 832       // Longs and doubles are passed in native word order, but misaligned
 833       // in the 32-bit build.
 834       assert(i > 0 && (sig_bt[i-1] == T_LONG || sig_bt[i-1] == T_DOUBLE), "missing half");
 835       continue;
 836     }
 837 
 838     // Pick up 0, 1 or 2 words from SP+offset.
 839 
 840     assert(!regs[i].second()->is_valid() || regs[i].first()->next() == regs[i].second(),
 841             "scrambled load targets?");
 842     // Load in argument order going down.
 843     int ld_off = (total_args_passed - i)*Interpreter::stackElementSize;
 844     // Point to interpreter value (vs. tag)
 845     int next_off = ld_off - Interpreter::stackElementSize;
 846     //
 847     //
 848     //
 849     VMReg r_1 = regs[i].first();
 850     VMReg r_2 = regs[i].second();
 851     if (!r_1->is_valid()) {
 852       assert(!r_2->is_valid(), "");
 853       continue;
 854     }
 855     if (r_1->is_stack()) {
 856       // Convert stack slot to an SP offset (+ wordSize to account for return address )
 857       int st_off = regs[i].first()->reg2stack()*VMRegImpl::stack_slot_size + wordSize;
 858 
 859       // We can use r13 as a temp here because compiled code doesn't need r13 as an input
 860       // and if we end up going thru a c2i because of a miss a reasonable value of r13
 861       // will be generated.
 862       if (!r_2->is_valid()) {
 863         // sign extend???
 864         __ movl(r13, Address(saved_sp, ld_off));
 865         __ movptr(Address(rsp, st_off), r13);
 866       } else {
 867         //
 868         // We are using two optoregs. This can be either T_OBJECT, T_ADDRESS, T_LONG, or T_DOUBLE
 869         // the interpreter allocates two slots but only uses one for thr T_LONG or T_DOUBLE case
 870         // So we must adjust where to pick up the data to match the interpreter.
 871         //
 872         // Interpreter local[n] == MSW, local[n+1] == LSW however locals
 873         // are accessed as negative so LSW is at LOW address
 874 
 875         // ld_off is MSW so get LSW
 876         const int offset = (sig_bt[i]==T_LONG||sig_bt[i]==T_DOUBLE)?
 877                            next_off : ld_off;
 878         __ movq(r13, Address(saved_sp, offset));
 879         // st_off is LSW (i.e. reg.first())
 880         __ movq(Address(rsp, st_off), r13);
 881       }
 882     } else if (r_1->is_Register()) {  // Register argument
 883       Register r = r_1->as_Register();
 884       assert(r != rax, "must be different");
 885       if (r_2->is_valid()) {
 886         //
 887         // We are using two VMRegs. This can be either T_OBJECT, T_ADDRESS, T_LONG, or T_DOUBLE
 888         // the interpreter allocates two slots but only uses one for thr T_LONG or T_DOUBLE case
 889         // So we must adjust where to pick up the data to match the interpreter.
 890 
 891         const int offset = (sig_bt[i]==T_LONG||sig_bt[i]==T_DOUBLE)?
 892                            next_off : ld_off;
 893 
 894         // this can be a misaligned move
 895         __ movq(r, Address(saved_sp, offset));
 896       } else {
 897         // sign extend and use a full word?
 898         __ movl(r, Address(saved_sp, ld_off));
 899       }
 900     } else {
 901       if (!r_2->is_valid()) {
 902         __ movflt(r_1->as_XMMRegister(), Address(saved_sp, ld_off));
 903       } else {
 904         __ movdbl(r_1->as_XMMRegister(), Address(saved_sp, next_off));
 905       }
 906     }
 907   }
 908 
 909   // 6243940 We might end up in handle_wrong_method if
 910   // the callee is deoptimized as we race thru here. If that
 911   // happens we don't want to take a safepoint because the
 912   // caller frame will look interpreted and arguments are now
 913   // "compiled" so it is much better to make this transition
 914   // invisible to the stack walking code. Unfortunately if
 915   // we try and find the callee by normal means a safepoint
 916   // is possible. So we stash the desired callee in the thread
 917   // and the vm will find there should this case occur.
 918 
 919   __ movptr(Address(r15_thread, JavaThread::callee_target_offset()), rbx);
 920 
 921   // put Method* where a c2i would expect should we end up there
 922   // only needed becaus eof c2 resolve stubs return Method* as a result in
 923   // rax
 924   __ mov(rax, rbx);
 925   __ jmp(r11);
 926 }
 927 
 928 // ---------------------------------------------------------------
 929 AdapterHandlerEntry* SharedRuntime::generate_i2c2i_adapters(MacroAssembler *masm,
 930                                                             int total_args_passed,
 931                                                             int comp_args_on_stack,
 932                                                             const BasicType *sig_bt,
 933                                                             const VMRegPair *regs,
 934                                                             AdapterFingerPrint* fingerprint) {
 935   address i2c_entry = __ pc();
 936 
 937   gen_i2c_adapter(masm, total_args_passed, comp_args_on_stack, sig_bt, regs);
 938 
 939   // -------------------------------------------------------------------------
 940   // Generate a C2I adapter.  On entry we know rbx holds the Method* during calls
 941   // to the interpreter.  The args start out packed in the compiled layout.  They
 942   // need to be unpacked into the interpreter layout.  This will almost always
 943   // require some stack space.  We grow the current (compiled) stack, then repack
 944   // the args.  We  finally end in a jump to the generic interpreter entry point.
 945   // On exit from the interpreter, the interpreter will restore our SP (lest the
 946   // compiled code, which relys solely on SP and not RBP, get sick).
 947 
 948   address c2i_unverified_entry = __ pc();
 949   Label skip_fixup;
 950   Label ok;
 951 
 952   Register holder = rax;
 953   Register receiver = j_rarg0;
 954   Register temp = rbx;
 955 
 956   {
 957     __ load_klass(temp, receiver);
 958     __ cmpptr(temp, Address(holder, CompiledICHolder::holder_klass_offset()));
 959     __ movptr(rbx, Address(holder, CompiledICHolder::holder_metadata_offset()));
 960     __ jcc(Assembler::equal, ok);
 961     __ jump(RuntimeAddress(SharedRuntime::get_ic_miss_stub()));
 962 
 963     __ bind(ok);
 964     // Method might have been compiled since the call site was patched to
 965     // interpreted if that is the case treat it as a miss so we can get
 966     // the call site corrected.
 967     __ cmpptr(Address(rbx, in_bytes(Method::code_offset())), (int32_t)NULL_WORD);
 968     __ jcc(Assembler::equal, skip_fixup);
 969     __ jump(RuntimeAddress(SharedRuntime::get_ic_miss_stub()));
 970   }
 971 
 972   address c2i_entry = __ pc();
 973 
 974   // Class initialization barrier for static methods
 975   address c2i_no_clinit_check_entry = NULL;
 976   if (VM_Version::supports_fast_class_init_checks()) {
 977     Label L_skip_barrier;
 978     Register method = rbx;
 979 
 980     { // Bypass the barrier for non-static methods
 981       Register flags  = rscratch1;
 982       __ movl(flags, Address(method, Method::access_flags_offset()));
 983       __ testl(flags, JVM_ACC_STATIC);
 984       __ jcc(Assembler::zero, L_skip_barrier); // non-static
 985     }
 986 
 987     Register klass = rscratch1;
 988     __ load_method_holder(klass, method);
 989     __ clinit_barrier(klass, r15_thread, &L_skip_barrier /*L_fast_path*/);
 990 
 991     __ jump(RuntimeAddress(SharedRuntime::get_handle_wrong_method_stub())); // slow path
 992 
 993     __ bind(L_skip_barrier);
 994     c2i_no_clinit_check_entry = __ pc();
 995   }
 996 
 997   BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
 998   bs->c2i_entry_barrier(masm);
 999 
1000   gen_c2i_adapter(masm, total_args_passed, comp_args_on_stack, sig_bt, regs, skip_fixup);
1001 
1002   __ flush();
1003   return AdapterHandlerLibrary::new_entry(fingerprint, i2c_entry, c2i_entry, c2i_unverified_entry, c2i_no_clinit_check_entry);
1004 }
1005 
1006 int SharedRuntime::c_calling_convention(const BasicType *sig_bt,
1007                                          VMRegPair *regs,
1008                                          VMRegPair *regs2,
1009                                          int total_args_passed) {
1010   assert(regs2 == NULL, "not needed on x86");
1011 // We return the amount of VMRegImpl stack slots we need to reserve for all
1012 // the arguments NOT counting out_preserve_stack_slots.
1013 
1014 // NOTE: These arrays will have to change when c1 is ported
1015 #ifdef _WIN64
1016     static const Register INT_ArgReg[Argument::n_int_register_parameters_c] = {
1017       c_rarg0, c_rarg1, c_rarg2, c_rarg3
1018     };
1019     static const XMMRegister FP_ArgReg[Argument::n_float_register_parameters_c] = {
1020       c_farg0, c_farg1, c_farg2, c_farg3
1021     };
1022 #else
1023     static const Register INT_ArgReg[Argument::n_int_register_parameters_c] = {
1024       c_rarg0, c_rarg1, c_rarg2, c_rarg3, c_rarg4, c_rarg5
1025     };
1026     static const XMMRegister FP_ArgReg[Argument::n_float_register_parameters_c] = {
1027       c_farg0, c_farg1, c_farg2, c_farg3,
1028       c_farg4, c_farg5, c_farg6, c_farg7
1029     };
1030 #endif // _WIN64
1031 
1032 
1033     uint int_args = 0;
1034     uint fp_args = 0;
1035     uint stk_args = 0; // inc by 2 each time
1036 
1037     for (int i = 0; i < total_args_passed; i++) {
1038       switch (sig_bt[i]) {
1039       case T_BOOLEAN:
1040       case T_CHAR:
1041       case T_BYTE:
1042       case T_SHORT:
1043       case T_INT:
1044         if (int_args < Argument::n_int_register_parameters_c) {
1045           regs[i].set1(INT_ArgReg[int_args++]->as_VMReg());
1046 #ifdef _WIN64
1047           fp_args++;
1048           // Allocate slots for callee to stuff register args the stack.
1049           stk_args += 2;
1050 #endif
1051         } else {
1052           regs[i].set1(VMRegImpl::stack2reg(stk_args));
1053           stk_args += 2;
1054         }
1055         break;
1056       case T_LONG:
1057         assert((i + 1) < total_args_passed && sig_bt[i + 1] == T_VOID, "expecting half");
1058         // fall through
1059       case T_OBJECT:
1060       case T_ARRAY:
1061       case T_ADDRESS:
1062       case T_METADATA:
1063         if (int_args < Argument::n_int_register_parameters_c) {
1064           regs[i].set2(INT_ArgReg[int_args++]->as_VMReg());
1065 #ifdef _WIN64
1066           fp_args++;
1067           stk_args += 2;
1068 #endif
1069         } else {
1070           regs[i].set2(VMRegImpl::stack2reg(stk_args));
1071           stk_args += 2;
1072         }
1073         break;
1074       case T_FLOAT:
1075         if (fp_args < Argument::n_float_register_parameters_c) {
1076           regs[i].set1(FP_ArgReg[fp_args++]->as_VMReg());
1077 #ifdef _WIN64
1078           int_args++;
1079           // Allocate slots for callee to stuff register args the stack.
1080           stk_args += 2;
1081 #endif
1082         } else {
1083           regs[i].set1(VMRegImpl::stack2reg(stk_args));
1084           stk_args += 2;
1085         }
1086         break;
1087       case T_DOUBLE:
1088         assert((i + 1) < total_args_passed && sig_bt[i + 1] == T_VOID, "expecting half");
1089         if (fp_args < Argument::n_float_register_parameters_c) {
1090           regs[i].set2(FP_ArgReg[fp_args++]->as_VMReg());
1091 #ifdef _WIN64
1092           int_args++;
1093           // Allocate slots for callee to stuff register args the stack.
1094           stk_args += 2;
1095 #endif
1096         } else {
1097           regs[i].set2(VMRegImpl::stack2reg(stk_args));
1098           stk_args += 2;
1099         }
1100         break;
1101       case T_VOID: // Halves of longs and doubles
1102         assert(i != 0 && (sig_bt[i - 1] == T_LONG || sig_bt[i - 1] == T_DOUBLE), "expecting half");
1103         regs[i].set_bad();
1104         break;
1105       default:
1106         ShouldNotReachHere();
1107         break;
1108       }
1109     }
1110 #ifdef _WIN64
1111   // windows abi requires that we always allocate enough stack space
1112   // for 4 64bit registers to be stored down.
1113   if (stk_args < 8) {
1114     stk_args = 8;
1115   }
1116 #endif // _WIN64
1117 
1118   return stk_args;
1119 }
1120 
1121 // On 64 bit we will store integer like items to the stack as
1122 // 64 bits items (sparc abi) even though java would only store
1123 // 32bits for a parameter. On 32bit it will simply be 32 bits
1124 // So this routine will do 32->32 on 32bit and 32->64 on 64bit
1125 static void move32_64(MacroAssembler* masm, VMRegPair src, VMRegPair dst) {
1126   if (src.first()->is_stack()) {
1127     if (dst.first()->is_stack()) {
1128       // stack to stack
1129       __ movslq(rax, Address(rbp, reg2offset_in(src.first())));
1130       __ movq(Address(rsp, reg2offset_out(dst.first())), rax);
1131     } else {
1132       // stack to reg
1133       __ movslq(dst.first()->as_Register(), Address(rbp, reg2offset_in(src.first())));
1134     }
1135   } else if (dst.first()->is_stack()) {
1136     // reg to stack
1137     // Do we really have to sign extend???
1138     // __ movslq(src.first()->as_Register(), src.first()->as_Register());
1139     __ movq(Address(rsp, reg2offset_out(dst.first())), src.first()->as_Register());
1140   } else {
1141     // Do we really have to sign extend???
1142     // __ movslq(dst.first()->as_Register(), src.first()->as_Register());
1143     if (dst.first() != src.first()) {
1144       __ movq(dst.first()->as_Register(), src.first()->as_Register());
1145     }
1146   }
1147 }
1148 
1149 static void move_ptr(MacroAssembler* masm, VMRegPair src, VMRegPair dst) {
1150   if (src.first()->is_stack()) {
1151     if (dst.first()->is_stack()) {
1152       // stack to stack
1153       __ movq(rax, Address(rbp, reg2offset_in(src.first())));
1154       __ movq(Address(rsp, reg2offset_out(dst.first())), rax);
1155     } else {
1156       // stack to reg
1157       __ movq(dst.first()->as_Register(), Address(rbp, reg2offset_in(src.first())));
1158     }
1159   } else if (dst.first()->is_stack()) {
1160     // reg to stack
1161     __ movq(Address(rsp, reg2offset_out(dst.first())), src.first()->as_Register());
1162   } else {
1163     if (dst.first() != src.first()) {
1164       __ movq(dst.first()->as_Register(), src.first()->as_Register());
1165     }
1166   }
1167 }
1168 
1169 // An oop arg. Must pass a handle not the oop itself
1170 static void object_move(MacroAssembler* masm,
1171                         OopMap* map,
1172                         int oop_handle_offset,
1173                         int framesize_in_slots,
1174                         VMRegPair src,
1175                         VMRegPair dst,
1176                         bool is_receiver,
1177                         int* receiver_offset) {
1178 
1179   // must pass a handle. First figure out the location we use as a handle
1180 
1181   Register rHandle = dst.first()->is_stack() ? rax : dst.first()->as_Register();
1182 
1183   // See if oop is NULL if it is we need no handle
1184 
1185   if (src.first()->is_stack()) {
1186 
1187     // Oop is already on the stack as an argument
1188     int offset_in_older_frame = src.first()->reg2stack() + SharedRuntime::out_preserve_stack_slots();
1189     map->set_oop(VMRegImpl::stack2reg(offset_in_older_frame + framesize_in_slots));
1190     if (is_receiver) {
1191       *receiver_offset = (offset_in_older_frame + framesize_in_slots) * VMRegImpl::stack_slot_size;
1192     }
1193 
1194     __ cmpptr(Address(rbp, reg2offset_in(src.first())), (int32_t)NULL_WORD);
1195     __ lea(rHandle, Address(rbp, reg2offset_in(src.first())));
1196     // conditionally move a NULL
1197     __ cmovptr(Assembler::equal, rHandle, Address(rbp, reg2offset_in(src.first())));
1198   } else {
1199 
1200     // Oop is in an a register we must store it to the space we reserve
1201     // on the stack for oop_handles and pass a handle if oop is non-NULL
1202 
1203     const Register rOop = src.first()->as_Register();
1204     int oop_slot;
1205     if (rOop == j_rarg0)
1206       oop_slot = 0;
1207     else if (rOop == j_rarg1)
1208       oop_slot = 1;
1209     else if (rOop == j_rarg2)
1210       oop_slot = 2;
1211     else if (rOop == j_rarg3)
1212       oop_slot = 3;
1213     else if (rOop == j_rarg4)
1214       oop_slot = 4;
1215     else {
1216       assert(rOop == j_rarg5, "wrong register");
1217       oop_slot = 5;
1218     }
1219 
1220     oop_slot = oop_slot * VMRegImpl::slots_per_word + oop_handle_offset;
1221     int offset = oop_slot*VMRegImpl::stack_slot_size;
1222 
1223     map->set_oop(VMRegImpl::stack2reg(oop_slot));
1224     // Store oop in handle area, may be NULL
1225     __ movptr(Address(rsp, offset), rOop);
1226     if (is_receiver) {
1227       *receiver_offset = offset;
1228     }
1229 
1230     __ cmpptr(rOop, (int32_t)NULL_WORD);
1231     __ lea(rHandle, Address(rsp, offset));
1232     // conditionally move a NULL from the handle area where it was just stored
1233     __ cmovptr(Assembler::equal, rHandle, Address(rsp, offset));
1234   }
1235 
1236   // If arg is on the stack then place it otherwise it is already in correct reg.
1237   if (dst.first()->is_stack()) {
1238     __ movptr(Address(rsp, reg2offset_out(dst.first())), rHandle);
1239   }
1240 }
1241 
1242 // A float arg may have to do float reg int reg conversion
1243 static void float_move(MacroAssembler* masm, VMRegPair src, VMRegPair dst) {
1244   assert(!src.second()->is_valid() && !dst.second()->is_valid(), "bad float_move");
1245 
1246   // The calling conventions assures us that each VMregpair is either
1247   // all really one physical register or adjacent stack slots.
1248   // This greatly simplifies the cases here compared to sparc.
1249 
1250   if (src.first()->is_stack()) {
1251     if (dst.first()->is_stack()) {
1252       __ movl(rax, Address(rbp, reg2offset_in(src.first())));
1253       __ movptr(Address(rsp, reg2offset_out(dst.first())), rax);
1254     } else {
1255       // stack to reg
1256       assert(dst.first()->is_XMMRegister(), "only expect xmm registers as parameters");
1257       __ movflt(dst.first()->as_XMMRegister(), Address(rbp, reg2offset_in(src.first())));
1258     }
1259   } else if (dst.first()->is_stack()) {
1260     // reg to stack
1261     assert(src.first()->is_XMMRegister(), "only expect xmm registers as parameters");
1262     __ movflt(Address(rsp, reg2offset_out(dst.first())), src.first()->as_XMMRegister());
1263   } else {
1264     // reg to reg
1265     // In theory these overlap but the ordering is such that this is likely a nop
1266     if ( src.first() != dst.first()) {
1267       __ movdbl(dst.first()->as_XMMRegister(),  src.first()->as_XMMRegister());
1268     }
1269   }
1270 }
1271 
1272 // A long move
1273 static void long_move(MacroAssembler* masm, VMRegPair src, VMRegPair dst) {
1274 
1275   // The calling conventions assures us that each VMregpair is either
1276   // all really one physical register or adjacent stack slots.
1277   // This greatly simplifies the cases here compared to sparc.
1278 
1279   if (src.is_single_phys_reg() ) {
1280     if (dst.is_single_phys_reg()) {
1281       if (dst.first() != src.first()) {
1282         __ mov(dst.first()->as_Register(), src.first()->as_Register());
1283       }
1284     } else {
1285       assert(dst.is_single_reg(), "not a stack pair");
1286       __ movq(Address(rsp, reg2offset_out(dst.first())), src.first()->as_Register());
1287     }
1288   } else if (dst.is_single_phys_reg()) {
1289     assert(src.is_single_reg(),  "not a stack pair");
1290     __ movq(dst.first()->as_Register(), Address(rbp, reg2offset_out(src.first())));
1291   } else {
1292     assert(src.is_single_reg() && dst.is_single_reg(), "not stack pairs");
1293     __ movq(rax, Address(rbp, reg2offset_in(src.first())));
1294     __ movq(Address(rsp, reg2offset_out(dst.first())), rax);
1295   }
1296 }
1297 
1298 // A double move
1299 static void double_move(MacroAssembler* masm, VMRegPair src, VMRegPair dst) {
1300 
1301   // The calling conventions assures us that each VMregpair is either
1302   // all really one physical register or adjacent stack slots.
1303   // This greatly simplifies the cases here compared to sparc.
1304 
1305   if (src.is_single_phys_reg() ) {
1306     if (dst.is_single_phys_reg()) {
1307       // In theory these overlap but the ordering is such that this is likely a nop
1308       if ( src.first() != dst.first()) {
1309         __ movdbl(dst.first()->as_XMMRegister(), src.first()->as_XMMRegister());
1310       }
1311     } else {
1312       assert(dst.is_single_reg(), "not a stack pair");
1313       __ movdbl(Address(rsp, reg2offset_out(dst.first())), src.first()->as_XMMRegister());
1314     }
1315   } else if (dst.is_single_phys_reg()) {
1316     assert(src.is_single_reg(),  "not a stack pair");
1317     __ movdbl(dst.first()->as_XMMRegister(), Address(rbp, reg2offset_out(src.first())));
1318   } else {
1319     assert(src.is_single_reg() && dst.is_single_reg(), "not stack pairs");
1320     __ movq(rax, Address(rbp, reg2offset_in(src.first())));
1321     __ movq(Address(rsp, reg2offset_out(dst.first())), rax);
1322   }
1323 }
1324 
1325 
1326 void SharedRuntime::save_native_result(MacroAssembler *masm, BasicType ret_type, int frame_slots) {
1327   // We always ignore the frame_slots arg and just use the space just below frame pointer
1328   // which by this time is free to use
1329   switch (ret_type) {
1330   case T_FLOAT:
1331     __ movflt(Address(rbp, -wordSize), xmm0);
1332     break;
1333   case T_DOUBLE:
1334     __ movdbl(Address(rbp, -wordSize), xmm0);
1335     break;
1336   case T_VOID:  break;
1337   default: {
1338     __ movptr(Address(rbp, -wordSize), rax);
1339     }
1340   }
1341 }
1342 
1343 void SharedRuntime::restore_native_result(MacroAssembler *masm, BasicType ret_type, int frame_slots) {
1344   // We always ignore the frame_slots arg and just use the space just below frame pointer
1345   // which by this time is free to use
1346   switch (ret_type) {
1347   case T_FLOAT:
1348     __ movflt(xmm0, Address(rbp, -wordSize));
1349     break;
1350   case T_DOUBLE:
1351     __ movdbl(xmm0, Address(rbp, -wordSize));
1352     break;
1353   case T_VOID:  break;
1354   default: {
1355     __ movptr(rax, Address(rbp, -wordSize));
1356     }
1357   }
1358 }
1359 
1360 static void save_args(MacroAssembler *masm, int arg_count, int first_arg, VMRegPair *args) {
1361     for ( int i = first_arg ; i < arg_count ; i++ ) {
1362       if (args[i].first()->is_Register()) {
1363         __ push(args[i].first()->as_Register());
1364       } else if (args[i].first()->is_XMMRegister()) {
1365         __ subptr(rsp, 2*wordSize);
1366         __ movdbl(Address(rsp, 0), args[i].first()->as_XMMRegister());
1367       }
1368     }
1369 }
1370 
1371 static void restore_args(MacroAssembler *masm, int arg_count, int first_arg, VMRegPair *args) {
1372     for ( int i = arg_count - 1 ; i >= first_arg ; i-- ) {
1373       if (args[i].first()->is_Register()) {
1374         __ pop(args[i].first()->as_Register());
1375       } else if (args[i].first()->is_XMMRegister()) {
1376         __ movdbl(args[i].first()->as_XMMRegister(), Address(rsp, 0));
1377         __ addptr(rsp, 2*wordSize);
1378       }
1379     }
1380 }
1381 
1382 
1383 static void save_or_restore_arguments(MacroAssembler* masm,
1384                                       const int stack_slots,
1385                                       const int total_in_args,
1386                                       const int arg_save_area,
1387                                       OopMap* map,
1388                                       VMRegPair* in_regs,
1389                                       BasicType* in_sig_bt) {
1390   // if map is non-NULL then the code should store the values,
1391   // otherwise it should load them.
1392   int slot = arg_save_area;
1393   // Save down double word first
1394   for ( int i = 0; i < total_in_args; i++) {
1395     if (in_regs[i].first()->is_XMMRegister() && in_sig_bt[i] == T_DOUBLE) {
1396       int offset = slot * VMRegImpl::stack_slot_size;
1397       slot += VMRegImpl::slots_per_word;
1398       assert(slot <= stack_slots, "overflow");
1399       if (map != NULL) {
1400         __ movdbl(Address(rsp, offset), in_regs[i].first()->as_XMMRegister());
1401       } else {
1402         __ movdbl(in_regs[i].first()->as_XMMRegister(), Address(rsp, offset));
1403       }
1404     }
1405     if (in_regs[i].first()->is_Register() &&
1406         (in_sig_bt[i] == T_LONG || in_sig_bt[i] == T_ARRAY)) {
1407       int offset = slot * VMRegImpl::stack_slot_size;
1408       if (map != NULL) {
1409         __ movq(Address(rsp, offset), in_regs[i].first()->as_Register());
1410         if (in_sig_bt[i] == T_ARRAY) {
1411           map->set_oop(VMRegImpl::stack2reg(slot));;
1412         }
1413       } else {
1414         __ movq(in_regs[i].first()->as_Register(), Address(rsp, offset));
1415       }
1416       slot += VMRegImpl::slots_per_word;
1417     }
1418   }
1419   // Save or restore single word registers
1420   for ( int i = 0; i < total_in_args; i++) {
1421     if (in_regs[i].first()->is_Register()) {
1422       int offset = slot * VMRegImpl::stack_slot_size;
1423       slot++;
1424       assert(slot <= stack_slots, "overflow");
1425 
1426       // Value is in an input register pass we must flush it to the stack
1427       const Register reg = in_regs[i].first()->as_Register();
1428       switch (in_sig_bt[i]) {
1429         case T_BOOLEAN:
1430         case T_CHAR:
1431         case T_BYTE:
1432         case T_SHORT:
1433         case T_INT:
1434           if (map != NULL) {
1435             __ movl(Address(rsp, offset), reg);
1436           } else {
1437             __ movl(reg, Address(rsp, offset));
1438           }
1439           break;
1440         case T_ARRAY:
1441         case T_LONG:
1442           // handled above
1443           break;
1444         case T_OBJECT:
1445         default: ShouldNotReachHere();
1446       }
1447     } else if (in_regs[i].first()->is_XMMRegister()) {
1448       if (in_sig_bt[i] == T_FLOAT) {
1449         int offset = slot * VMRegImpl::stack_slot_size;
1450         slot++;
1451         assert(slot <= stack_slots, "overflow");
1452         if (map != NULL) {
1453           __ movflt(Address(rsp, offset), in_regs[i].first()->as_XMMRegister());
1454         } else {
1455           __ movflt(in_regs[i].first()->as_XMMRegister(), Address(rsp, offset));
1456         }
1457       }
1458     } else if (in_regs[i].first()->is_stack()) {
1459       if (in_sig_bt[i] == T_ARRAY && map != NULL) {
1460         int offset_in_older_frame = in_regs[i].first()->reg2stack() + SharedRuntime::out_preserve_stack_slots();
1461         map->set_oop(VMRegImpl::stack2reg(offset_in_older_frame + stack_slots));
1462       }
1463     }
1464   }
1465 }
1466 
1467 // Pin object, return pinned object or null in rax
1468 static void gen_pin_object(MacroAssembler* masm,
1469                            VMRegPair reg) {
1470   __ block_comment("gen_pin_object {");
1471 
1472   // rax always contains oop, either incoming or
1473   // pinned.
1474   Register tmp_reg = rax;
1475 
1476   Label is_null;
1477   VMRegPair tmp;
1478   VMRegPair in_reg = reg;
1479 
1480   tmp.set_ptr(tmp_reg->as_VMReg());
1481   if (reg.first()->is_stack()) {
1482     // Load the arg up from the stack
1483     move_ptr(masm, reg, tmp);
1484     reg = tmp;
1485   } else {
1486     __ movptr(rax, reg.first()->as_Register());
1487   }
1488   __ testptr(reg.first()->as_Register(), reg.first()->as_Register());
1489   __ jccb(Assembler::equal, is_null);
1490 
1491   if (reg.first()->as_Register() != c_rarg1) {
1492     __ movptr(c_rarg1, reg.first()->as_Register());
1493   }
1494 
1495   __ call_VM_leaf(
1496     CAST_FROM_FN_PTR(address, SharedRuntime::pin_object),
1497     r15_thread, c_rarg1);
1498 
1499   __ bind(is_null);
1500   __ block_comment("} gen_pin_object");
1501 }
1502 
1503 // Unpin object
1504 static void gen_unpin_object(MacroAssembler* masm,
1505                              VMRegPair reg) {
1506   __ block_comment("gen_unpin_object {");
1507   Label is_null;
1508 
1509   if (reg.first()->is_stack()) {
1510     __ movptr(c_rarg1, Address(rbp, reg2offset_in(reg.first())));
1511   } else if (reg.first()->as_Register() != c_rarg1) {
1512     __ movptr(c_rarg1, reg.first()->as_Register());
1513   }
1514 
1515   __ testptr(c_rarg1, c_rarg1);
1516   __ jccb(Assembler::equal, is_null);
1517 
1518   __ call_VM_leaf(
1519     CAST_FROM_FN_PTR(address, SharedRuntime::unpin_object),
1520     r15_thread, c_rarg1);
1521 
1522   __ bind(is_null);
1523   __ block_comment("} gen_unpin_object");
1524 }
1525 
1526 // Check GCLocker::needs_gc and enter the runtime if it's true.  This
1527 // keeps a new JNI critical region from starting until a GC has been
1528 // forced.  Save down any oops in registers and describe them in an
1529 // OopMap.
1530 static void check_needs_gc_for_critical_native(MacroAssembler* masm,
1531                                                int stack_slots,
1532                                                int total_c_args,
1533                                                int total_in_args,
1534                                                int arg_save_area,
1535                                                OopMapSet* oop_maps,
1536                                                VMRegPair* in_regs,
1537                                                BasicType* in_sig_bt) {
1538   __ block_comment("check GCLocker::needs_gc");
1539   Label cont;
1540   __ cmp8(ExternalAddress((address)GCLocker::needs_gc_address()), false);
1541   __ jcc(Assembler::equal, cont);
1542 
1543   // Save down any incoming oops and call into the runtime to halt for a GC
1544 
1545   OopMap* map = new OopMap(stack_slots * 2, 0 /* arg_slots*/);
1546   save_or_restore_arguments(masm, stack_slots, total_in_args,
1547                             arg_save_area, map, in_regs, in_sig_bt);
1548 
1549   address the_pc = __ pc();
1550   oop_maps->add_gc_map( __ offset(), map);
1551   __ set_last_Java_frame(rsp, noreg, the_pc);
1552 
1553   __ block_comment("block_for_jni_critical");
1554   __ movptr(c_rarg0, r15_thread);
1555   __ mov(r12, rsp); // remember sp
1556   __ subptr(rsp, frame::arg_reg_save_area_bytes); // windows
1557   __ andptr(rsp, -16); // align stack as required by ABI
1558   __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, SharedRuntime::block_for_jni_critical)));
1559   __ mov(rsp, r12); // restore sp
1560   __ reinit_heapbase();
1561 
1562   __ reset_last_Java_frame(false);
1563 
1564   save_or_restore_arguments(masm, stack_slots, total_in_args,
1565                             arg_save_area, NULL, in_regs, in_sig_bt);
1566   __ bind(cont);
1567 #ifdef ASSERT
1568   if (StressCriticalJNINatives) {
1569     // Stress register saving
1570     OopMap* map = new OopMap(stack_slots * 2, 0 /* arg_slots*/);
1571     save_or_restore_arguments(masm, stack_slots, total_in_args,
1572                               arg_save_area, map, in_regs, in_sig_bt);
1573     // Destroy argument registers
1574     for (int i = 0; i < total_in_args - 1; i++) {
1575       if (in_regs[i].first()->is_Register()) {
1576         const Register reg = in_regs[i].first()->as_Register();
1577         __ xorptr(reg, reg);
1578       } else if (in_regs[i].first()->is_XMMRegister()) {
1579         __ xorpd(in_regs[i].first()->as_XMMRegister(), in_regs[i].first()->as_XMMRegister());
1580       } else if (in_regs[i].first()->is_FloatRegister()) {
1581         ShouldNotReachHere();
1582       } else if (in_regs[i].first()->is_stack()) {
1583         // Nothing to do
1584       } else {
1585         ShouldNotReachHere();
1586       }
1587       if (in_sig_bt[i] == T_LONG || in_sig_bt[i] == T_DOUBLE) {
1588         i++;
1589       }
1590     }
1591 
1592     save_or_restore_arguments(masm, stack_slots, total_in_args,
1593                               arg_save_area, NULL, in_regs, in_sig_bt);
1594   }
1595 #endif
1596 }
1597 
1598 // Unpack an array argument into a pointer to the body and the length
1599 // if the array is non-null, otherwise pass 0 for both.
1600 static void unpack_array_argument(MacroAssembler* masm, VMRegPair reg, BasicType in_elem_type, VMRegPair body_arg, VMRegPair length_arg) {
1601   Register tmp_reg = rax;
1602   assert(!body_arg.first()->is_Register() || body_arg.first()->as_Register() != tmp_reg,
1603          "possible collision");
1604   assert(!length_arg.first()->is_Register() || length_arg.first()->as_Register() != tmp_reg,
1605          "possible collision");
1606 
1607   __ block_comment("unpack_array_argument {");
1608 
1609   // Pass the length, ptr pair
1610   Label is_null, done;
1611   VMRegPair tmp;
1612   tmp.set_ptr(tmp_reg->as_VMReg());
1613   if (reg.first()->is_stack()) {
1614     // Load the arg up from the stack
1615     move_ptr(masm, reg, tmp);
1616     reg = tmp;
1617   }
1618   __ testptr(reg.first()->as_Register(), reg.first()->as_Register());
1619   __ jccb(Assembler::equal, is_null);
1620   __ lea(tmp_reg, Address(reg.first()->as_Register(), arrayOopDesc::base_offset_in_bytes(in_elem_type)));
1621   move_ptr(masm, tmp, body_arg);
1622   // load the length relative to the body.
1623   __ movl(tmp_reg, Address(tmp_reg, arrayOopDesc::length_offset_in_bytes() -
1624                            arrayOopDesc::base_offset_in_bytes(in_elem_type)));
1625   move32_64(masm, tmp, length_arg);
1626   __ jmpb(done);
1627   __ bind(is_null);
1628   // Pass zeros
1629   __ xorptr(tmp_reg, tmp_reg);
1630   move_ptr(masm, tmp, body_arg);
1631   move32_64(masm, tmp, length_arg);
1632   __ bind(done);
1633 
1634   __ block_comment("} unpack_array_argument");
1635 }
1636 
1637 
1638 // Different signatures may require very different orders for the move
1639 // to avoid clobbering other arguments.  There's no simple way to
1640 // order them safely.  Compute a safe order for issuing stores and
1641 // break any cycles in those stores.  This code is fairly general but
1642 // it's not necessary on the other platforms so we keep it in the
1643 // platform dependent code instead of moving it into a shared file.
1644 // (See bugs 7013347 & 7145024.)
1645 // Note that this code is specific to LP64.
1646 class ComputeMoveOrder: public StackObj {
1647   class MoveOperation: public ResourceObj {
1648     friend class ComputeMoveOrder;
1649    private:
1650     VMRegPair        _src;
1651     VMRegPair        _dst;
1652     int              _src_index;
1653     int              _dst_index;
1654     bool             _processed;
1655     MoveOperation*  _next;
1656     MoveOperation*  _prev;
1657 
1658     static int get_id(VMRegPair r) {
1659       return r.first()->value();
1660     }
1661 
1662    public:
1663     MoveOperation(int src_index, VMRegPair src, int dst_index, VMRegPair dst):
1664       _src(src)
1665     , _dst(dst)
1666     , _src_index(src_index)
1667     , _dst_index(dst_index)
1668     , _processed(false)
1669     , _next(NULL)
1670     , _prev(NULL) {
1671     }
1672 
1673     VMRegPair src() const              { return _src; }
1674     int src_id() const                 { return get_id(src()); }
1675     int src_index() const              { return _src_index; }
1676     VMRegPair dst() const              { return _dst; }
1677     void set_dst(int i, VMRegPair dst) { _dst_index = i, _dst = dst; }
1678     int dst_index() const              { return _dst_index; }
1679     int dst_id() const                 { return get_id(dst()); }
1680     MoveOperation* next() const       { return _next; }
1681     MoveOperation* prev() const       { return _prev; }
1682     void set_processed()               { _processed = true; }
1683     bool is_processed() const          { return _processed; }
1684 
1685     // insert
1686     void break_cycle(VMRegPair temp_register) {
1687       // create a new store following the last store
1688       // to move from the temp_register to the original
1689       MoveOperation* new_store = new MoveOperation(-1, temp_register, dst_index(), dst());
1690 
1691       // break the cycle of links and insert new_store at the end
1692       // break the reverse link.
1693       MoveOperation* p = prev();
1694       assert(p->next() == this, "must be");
1695       _prev = NULL;
1696       p->_next = new_store;
1697       new_store->_prev = p;
1698 
1699       // change the original store to save it's value in the temp.
1700       set_dst(-1, temp_register);
1701     }
1702 
1703     void link(GrowableArray<MoveOperation*>& killer) {
1704       // link this store in front the store that it depends on
1705       MoveOperation* n = killer.at_grow(src_id(), NULL);
1706       if (n != NULL) {
1707         assert(_next == NULL && n->_prev == NULL, "shouldn't have been set yet");
1708         _next = n;
1709         n->_prev = this;
1710       }
1711     }
1712   };
1713 
1714  private:
1715   GrowableArray<MoveOperation*> edges;
1716 
1717  public:
1718   ComputeMoveOrder(int total_in_args, VMRegPair* in_regs, int total_c_args, VMRegPair* out_regs,
1719                     BasicType* in_sig_bt, GrowableArray<int>& arg_order, VMRegPair tmp_vmreg) {
1720     // Move operations where the dest is the stack can all be
1721     // scheduled first since they can't interfere with the other moves.
1722     for (int i = total_in_args - 1, c_arg = total_c_args - 1; i >= 0; i--, c_arg--) {
1723       if (in_sig_bt[i] == T_ARRAY) {
1724         c_arg--;
1725         if (out_regs[c_arg].first()->is_stack() &&
1726             out_regs[c_arg + 1].first()->is_stack()) {
1727           arg_order.push(i);
1728           arg_order.push(c_arg);
1729         } else {
1730           if (out_regs[c_arg].first()->is_stack() ||
1731               in_regs[i].first() == out_regs[c_arg].first()) {
1732             add_edge(i, in_regs[i].first(), c_arg, out_regs[c_arg + 1]);
1733           } else {
1734             add_edge(i, in_regs[i].first(), c_arg, out_regs[c_arg]);
1735           }
1736         }
1737       } else if (in_sig_bt[i] == T_VOID) {
1738         arg_order.push(i);
1739         arg_order.push(c_arg);
1740       } else {
1741         if (out_regs[c_arg].first()->is_stack() ||
1742             in_regs[i].first() == out_regs[c_arg].first()) {
1743           arg_order.push(i);
1744           arg_order.push(c_arg);
1745         } else {
1746           add_edge(i, in_regs[i].first(), c_arg, out_regs[c_arg]);
1747         }
1748       }
1749     }
1750     // Break any cycles in the register moves and emit the in the
1751     // proper order.
1752     GrowableArray<MoveOperation*>* stores = get_store_order(tmp_vmreg);
1753     for (int i = 0; i < stores->length(); i++) {
1754       arg_order.push(stores->at(i)->src_index());
1755       arg_order.push(stores->at(i)->dst_index());
1756     }
1757  }
1758 
1759   // Collected all the move operations
1760   void add_edge(int src_index, VMRegPair src, int dst_index, VMRegPair dst) {
1761     if (src.first() == dst.first()) return;
1762     edges.append(new MoveOperation(src_index, src, dst_index, dst));
1763   }
1764 
1765   // Walk the edges breaking cycles between moves.  The result list
1766   // can be walked in order to produce the proper set of loads
1767   GrowableArray<MoveOperation*>* get_store_order(VMRegPair temp_register) {
1768     // Record which moves kill which values
1769     GrowableArray<MoveOperation*> killer;
1770     for (int i = 0; i < edges.length(); i++) {
1771       MoveOperation* s = edges.at(i);
1772       assert(killer.at_grow(s->dst_id(), NULL) == NULL, "only one killer");
1773       killer.at_put_grow(s->dst_id(), s, NULL);
1774     }
1775     assert(killer.at_grow(MoveOperation::get_id(temp_register), NULL) == NULL,
1776            "make sure temp isn't in the registers that are killed");
1777 
1778     // create links between loads and stores
1779     for (int i = 0; i < edges.length(); i++) {
1780       edges.at(i)->link(killer);
1781     }
1782 
1783     // at this point, all the move operations are chained together
1784     // in a doubly linked list.  Processing it backwards finds
1785     // the beginning of the chain, forwards finds the end.  If there's
1786     // a cycle it can be broken at any point,  so pick an edge and walk
1787     // backward until the list ends or we end where we started.
1788     GrowableArray<MoveOperation*>* stores = new GrowableArray<MoveOperation*>();
1789     for (int e = 0; e < edges.length(); e++) {
1790       MoveOperation* s = edges.at(e);
1791       if (!s->is_processed()) {
1792         MoveOperation* start = s;
1793         // search for the beginning of the chain or cycle
1794         while (start->prev() != NULL && start->prev() != s) {
1795           start = start->prev();
1796         }
1797         if (start->prev() == s) {
1798           start->break_cycle(temp_register);
1799         }
1800         // walk the chain forward inserting to store list
1801         while (start != NULL) {
1802           stores->append(start);
1803           start->set_processed();
1804           start = start->next();
1805         }
1806       }
1807     }
1808     return stores;
1809   }
1810 };
1811 
1812 static void verify_oop_args(MacroAssembler* masm,
1813                             const methodHandle& method,
1814                             const BasicType* sig_bt,
1815                             const VMRegPair* regs) {
1816   Register temp_reg = rbx;  // not part of any compiled calling seq
1817   if (VerifyOops) {
1818     for (int i = 0; i < method->size_of_parameters(); i++) {
1819       if (is_reference_type(sig_bt[i])) {
1820         VMReg r = regs[i].first();
1821         assert(r->is_valid(), "bad oop arg");
1822         if (r->is_stack()) {
1823           __ movptr(temp_reg, Address(rsp, r->reg2stack() * VMRegImpl::stack_slot_size + wordSize));
1824           __ verify_oop(temp_reg);
1825         } else {
1826           __ verify_oop(r->as_Register());
1827         }
1828       }
1829     }
1830   }
1831 }
1832 
1833 static void gen_special_dispatch(MacroAssembler* masm,
1834                                  const methodHandle& method,
1835                                  const BasicType* sig_bt,
1836                                  const VMRegPair* regs) {
1837   verify_oop_args(masm, method, sig_bt, regs);
1838   vmIntrinsics::ID iid = method->intrinsic_id();
1839 
1840   // Now write the args into the outgoing interpreter space
1841   bool     has_receiver   = false;
1842   Register receiver_reg   = noreg;
1843   int      member_arg_pos = -1;
1844   Register member_reg     = noreg;
1845   int      ref_kind       = MethodHandles::signature_polymorphic_intrinsic_ref_kind(iid);
1846   if (ref_kind != 0) {
1847     member_arg_pos = method->size_of_parameters() - 1;  // trailing MemberName argument
1848     member_reg = rbx;  // known to be free at this point
1849     has_receiver = MethodHandles::ref_kind_has_receiver(ref_kind);
1850   } else if (iid == vmIntrinsics::_invokeBasic) {
1851     has_receiver = true;
1852   } else {
1853     fatal("unexpected intrinsic id %d", iid);
1854   }
1855 
1856   if (member_reg != noreg) {
1857     // Load the member_arg into register, if necessary.
1858     SharedRuntime::check_member_name_argument_is_last_argument(method, sig_bt, regs);
1859     VMReg r = regs[member_arg_pos].first();
1860     if (r->is_stack()) {
1861       __ movptr(member_reg, Address(rsp, r->reg2stack() * VMRegImpl::stack_slot_size + wordSize));
1862     } else {
1863       // no data motion is needed
1864       member_reg = r->as_Register();
1865     }
1866   }
1867 
1868   if (has_receiver) {
1869     // Make sure the receiver is loaded into a register.
1870     assert(method->size_of_parameters() > 0, "oob");
1871     assert(sig_bt[0] == T_OBJECT, "receiver argument must be an object");
1872     VMReg r = regs[0].first();
1873     assert(r->is_valid(), "bad receiver arg");
1874     if (r->is_stack()) {
1875       // Porting note:  This assumes that compiled calling conventions always
1876       // pass the receiver oop in a register.  If this is not true on some
1877       // platform, pick a temp and load the receiver from stack.
1878       fatal("receiver always in a register");
1879       receiver_reg = j_rarg0;  // known to be free at this point
1880       __ movptr(receiver_reg, Address(rsp, r->reg2stack() * VMRegImpl::stack_slot_size + wordSize));
1881     } else {
1882       // no data motion is needed
1883       receiver_reg = r->as_Register();
1884     }
1885   }
1886 
1887   // Figure out which address we are really jumping to:
1888   MethodHandles::generate_method_handle_dispatch(masm, iid,
1889                                                  receiver_reg, member_reg, /*for_compiler_entry:*/ true);
1890 }
1891 
1892 // ---------------------------------------------------------------------------
1893 // Generate a native wrapper for a given method.  The method takes arguments
1894 // in the Java compiled code convention, marshals them to the native
1895 // convention (handlizes oops, etc), transitions to native, makes the call,
1896 // returns to java state (possibly blocking), unhandlizes any result and
1897 // returns.
1898 //
1899 // Critical native functions are a shorthand for the use of
1900 // GetPrimtiveArrayCritical and disallow the use of any other JNI
1901 // functions.  The wrapper is expected to unpack the arguments before
1902 // passing them to the callee and perform checks before and after the
1903 // native call to ensure that they GCLocker
1904 // lock_critical/unlock_critical semantics are followed.  Some other
1905 // parts of JNI setup are skipped like the tear down of the JNI handle
1906 // block and the check for pending exceptions it's impossible for them
1907 // to be thrown.
1908 //
1909 // They are roughly structured like this:
1910 //    if (GCLocker::needs_gc())
1911 //      SharedRuntime::block_for_jni_critical();
1912 //    tranistion to thread_in_native
1913 //    unpack arrray arguments and call native entry point
1914 //    check for safepoint in progress
1915 //    check if any thread suspend flags are set
1916 //      call into JVM and possible unlock the JNI critical
1917 //      if a GC was suppressed while in the critical native.
1918 //    transition back to thread_in_Java
1919 //    return to caller
1920 //
1921 nmethod* SharedRuntime::generate_native_wrapper(MacroAssembler* masm,
1922                                                 const methodHandle& method,
1923                                                 int compile_id,
1924                                                 BasicType* in_sig_bt,
1925                                                 VMRegPair* in_regs,
1926                                                 BasicType ret_type,
1927                                                 address critical_entry) {
1928   if (method->is_method_handle_intrinsic()) {
1929     vmIntrinsics::ID iid = method->intrinsic_id();
1930     intptr_t start = (intptr_t)__ pc();
1931     int vep_offset = ((intptr_t)__ pc()) - start;
1932     gen_special_dispatch(masm,
1933                          method,
1934                          in_sig_bt,
1935                          in_regs);
1936     int frame_complete = ((intptr_t)__ pc()) - start;  // not complete, period
1937     __ flush();
1938     int stack_slots = SharedRuntime::out_preserve_stack_slots();  // no out slots at all, actually
1939     return nmethod::new_native_nmethod(method,
1940                                        compile_id,
1941                                        masm->code(),
1942                                        vep_offset,
1943                                        frame_complete,
1944                                        stack_slots / VMRegImpl::slots_per_word,
1945                                        in_ByteSize(-1),
1946                                        in_ByteSize(-1),
1947                                        (OopMapSet*)NULL);
1948   }
1949   bool is_critical_native = true;
1950   address native_func = critical_entry;
1951   if (native_func == NULL) {
1952     native_func = method->native_function();
1953     is_critical_native = false;
1954   }
1955   assert(native_func != NULL, "must have function");
1956 
1957   // An OopMap for lock (and class if static)
1958   OopMapSet *oop_maps = new OopMapSet();
1959   intptr_t start = (intptr_t)__ pc();
1960 
1961   // We have received a description of where all the java arg are located
1962   // on entry to the wrapper. We need to convert these args to where
1963   // the jni function will expect them. To figure out where they go
1964   // we convert the java signature to a C signature by inserting
1965   // the hidden arguments as arg[0] and possibly arg[1] (static method)
1966 
1967   const int total_in_args = method->size_of_parameters();
1968   int total_c_args = total_in_args;
1969   if (!is_critical_native) {
1970     total_c_args += 1;
1971     if (method->is_static()) {
1972       total_c_args++;
1973     }
1974   } else {
1975     for (int i = 0; i < total_in_args; i++) {
1976       if (in_sig_bt[i] == T_ARRAY) {
1977         total_c_args++;
1978       }
1979     }
1980   }
1981 
1982   BasicType* out_sig_bt = NEW_RESOURCE_ARRAY(BasicType, total_c_args);
1983   VMRegPair* out_regs   = NEW_RESOURCE_ARRAY(VMRegPair, total_c_args);
1984   BasicType* in_elem_bt = NULL;
1985 
1986   int argc = 0;
1987   if (!is_critical_native) {
1988     out_sig_bt[argc++] = T_ADDRESS;
1989     if (method->is_static()) {
1990       out_sig_bt[argc++] = T_OBJECT;
1991     }
1992 
1993     for (int i = 0; i < total_in_args ; i++ ) {
1994       out_sig_bt[argc++] = in_sig_bt[i];
1995     }
1996   } else {
1997     in_elem_bt = NEW_RESOURCE_ARRAY(BasicType, total_in_args);
1998     SignatureStream ss(method->signature());
1999     for (int i = 0; i < total_in_args ; i++ ) {
2000       if (in_sig_bt[i] == T_ARRAY) {
2001         // Arrays are passed as int, elem* pair
2002         out_sig_bt[argc++] = T_INT;
2003         out_sig_bt[argc++] = T_ADDRESS;
2004         Symbol* atype = ss.as_symbol();
2005         const char* at = atype->as_C_string();
2006         if (strlen(at) == 2) {
2007           assert(at[0] == '[', "must be");
2008           switch (at[1]) {
2009             case 'B': in_elem_bt[i]  = T_BYTE; break;
2010             case 'C': in_elem_bt[i]  = T_CHAR; break;
2011             case 'D': in_elem_bt[i]  = T_DOUBLE; break;
2012             case 'F': in_elem_bt[i]  = T_FLOAT; break;
2013             case 'I': in_elem_bt[i]  = T_INT; break;
2014             case 'J': in_elem_bt[i]  = T_LONG; break;
2015             case 'S': in_elem_bt[i]  = T_SHORT; break;
2016             case 'Z': in_elem_bt[i]  = T_BOOLEAN; break;
2017             default: ShouldNotReachHere();
2018           }
2019         }
2020       } else {
2021         out_sig_bt[argc++] = in_sig_bt[i];
2022         in_elem_bt[i] = T_VOID;
2023       }
2024       if (in_sig_bt[i] != T_VOID) {
2025         assert(in_sig_bt[i] == ss.type(), "must match");
2026         ss.next();
2027       }
2028     }
2029   }
2030 
2031   // Now figure out where the args must be stored and how much stack space
2032   // they require.
2033   int out_arg_slots;
2034   out_arg_slots = c_calling_convention(out_sig_bt, out_regs, NULL, total_c_args);
2035 
2036   // Compute framesize for the wrapper.  We need to handlize all oops in
2037   // incoming registers
2038 
2039   // Calculate the total number of stack slots we will need.
2040 
2041   // First count the abi requirement plus all of the outgoing args
2042   int stack_slots = SharedRuntime::out_preserve_stack_slots() + out_arg_slots;
2043 
2044   // Now the space for the inbound oop handle area
2045   int total_save_slots = 6 * VMRegImpl::slots_per_word;  // 6 arguments passed in registers
2046   if (is_critical_native) {
2047     // Critical natives may have to call out so they need a save area
2048     // for register arguments.
2049     int double_slots = 0;
2050     int single_slots = 0;
2051     for ( int i = 0; i < total_in_args; i++) {
2052       if (in_regs[i].first()->is_Register()) {
2053         const Register reg = in_regs[i].first()->as_Register();
2054         switch (in_sig_bt[i]) {
2055           case T_BOOLEAN:
2056           case T_BYTE:
2057           case T_SHORT:
2058           case T_CHAR:
2059           case T_INT:  single_slots++; break;
2060           case T_ARRAY:  // specific to LP64 (7145024)
2061           case T_LONG: double_slots++; break;
2062           default:  ShouldNotReachHere();
2063         }
2064       } else if (in_regs[i].first()->is_XMMRegister()) {
2065         switch (in_sig_bt[i]) {
2066           case T_FLOAT:  single_slots++; break;
2067           case T_DOUBLE: double_slots++; break;
2068           default:  ShouldNotReachHere();
2069         }
2070       } else if (in_regs[i].first()->is_FloatRegister()) {
2071         ShouldNotReachHere();
2072       }
2073     }
2074     total_save_slots = double_slots * 2 + single_slots;
2075     // align the save area
2076     if (double_slots != 0) {
2077       stack_slots = align_up(stack_slots, 2);
2078     }
2079   }
2080 
2081   int oop_handle_offset = stack_slots;
2082   stack_slots += total_save_slots;
2083 
2084   // Now any space we need for handlizing a klass if static method
2085 
2086   int klass_slot_offset = 0;
2087   int klass_offset = -1;
2088   int lock_slot_offset = 0;
2089   bool is_static = false;
2090 
2091   if (method->is_static()) {
2092     klass_slot_offset = stack_slots;
2093     stack_slots += VMRegImpl::slots_per_word;
2094     klass_offset = klass_slot_offset * VMRegImpl::stack_slot_size;
2095     is_static = true;
2096   }
2097 
2098   // Plus a lock if needed
2099 
2100   if (method->is_synchronized()) {
2101     lock_slot_offset = stack_slots;
2102     stack_slots += VMRegImpl::slots_per_word;
2103   }
2104 
2105   // Now a place (+2) to save return values or temp during shuffling
2106   // + 4 for return address (which we own) and saved rbp
2107   stack_slots += 6;
2108 
2109   // Ok The space we have allocated will look like:
2110   //
2111   //
2112   // FP-> |                     |
2113   //      |---------------------|
2114   //      | 2 slots for moves   |
2115   //      |---------------------|
2116   //      | lock box (if sync)  |
2117   //      |---------------------| <- lock_slot_offset
2118   //      | klass (if static)   |
2119   //      |---------------------| <- klass_slot_offset
2120   //      | oopHandle area      |
2121   //      |---------------------| <- oop_handle_offset (6 java arg registers)
2122   //      | outbound memory     |
2123   //      | based arguments     |
2124   //      |                     |
2125   //      |---------------------|
2126   //      |                     |
2127   // SP-> | out_preserved_slots |
2128   //
2129   //
2130 
2131 
2132   // Now compute actual number of stack words we need rounding to make
2133   // stack properly aligned.
2134   stack_slots = align_up(stack_slots, StackAlignmentInSlots);
2135 
2136   int stack_size = stack_slots * VMRegImpl::stack_slot_size;
2137 
2138   // First thing make an ic check to see if we should even be here
2139 
2140   // We are free to use all registers as temps without saving them and
2141   // restoring them except rbp. rbp is the only callee save register
2142   // as far as the interpreter and the compiler(s) are concerned.
2143 
2144 
2145   const Register ic_reg = rax;
2146   const Register receiver = j_rarg0;
2147 
2148   Label hit;
2149   Label exception_pending;
2150 
2151   assert_different_registers(ic_reg, receiver, rscratch1);
2152   __ verify_oop(receiver);
2153   __ load_klass(rscratch1, receiver);
2154   __ cmpq(ic_reg, rscratch1);
2155   __ jcc(Assembler::equal, hit);
2156 
2157   __ jump(RuntimeAddress(SharedRuntime::get_ic_miss_stub()));
2158 
2159   // Verified entry point must be aligned
2160   __ align(8);
2161 
2162   __ bind(hit);
2163 
2164   int vep_offset = ((intptr_t)__ pc()) - start;
2165 
2166   if (VM_Version::supports_fast_class_init_checks() && method->needs_clinit_barrier()) {
2167     Label L_skip_barrier;
2168     Register klass = r10;
2169     __ mov_metadata(klass, method->method_holder()); // InstanceKlass*
2170     __ clinit_barrier(klass, r15_thread, &L_skip_barrier /*L_fast_path*/);
2171 
2172     __ jump(RuntimeAddress(SharedRuntime::get_handle_wrong_method_stub())); // slow path
2173 
2174     __ bind(L_skip_barrier);
2175   }
2176 
2177 #ifdef COMPILER1
2178   // For Object.hashCode, System.identityHashCode try to pull hashCode from object header if available.
2179   if ((InlineObjectHash && method->intrinsic_id() == vmIntrinsics::_hashCode) || (method->intrinsic_id() == vmIntrinsics::_identityHashCode)) {
2180     inline_check_hashcode_from_object_header(masm, method, j_rarg0 /*obj_reg*/, rax /*result*/);
2181   }
2182 #endif // COMPILER1
2183 
2184   // The instruction at the verified entry point must be 5 bytes or longer
2185   // because it can be patched on the fly by make_non_entrant. The stack bang
2186   // instruction fits that requirement.
2187 
2188   // Generate stack overflow check
2189 
2190   if (UseStackBanging) {
2191     __ bang_stack_with_offset((int)JavaThread::stack_shadow_zone_size());
2192   } else {
2193     // need a 5 byte instruction to allow MT safe patching to non-entrant
2194     __ fat_nop();
2195   }
2196 
2197   // Generate a new frame for the wrapper.
2198   __ enter();
2199   // -2 because return address is already present and so is saved rbp
2200   __ subptr(rsp, stack_size - 2*wordSize);
2201 
2202   BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
2203   bs->nmethod_entry_barrier(masm);
2204 
2205   // Frame is now completed as far as size and linkage.
2206   int frame_complete = ((intptr_t)__ pc()) - start;
2207 
2208     if (UseRTMLocking) {
2209       // Abort RTM transaction before calling JNI
2210       // because critical section will be large and will be
2211       // aborted anyway. Also nmethod could be deoptimized.
2212       __ xabort(0);
2213     }
2214 
2215 #ifdef ASSERT
2216     {
2217       Label L;
2218       __ mov(rax, rsp);
2219       __ andptr(rax, -16); // must be 16 byte boundary (see amd64 ABI)
2220       __ cmpptr(rax, rsp);
2221       __ jcc(Assembler::equal, L);
2222       __ stop("improperly aligned stack");
2223       __ bind(L);
2224     }
2225 #endif /* ASSERT */
2226 
2227 
2228   // We use r14 as the oop handle for the receiver/klass
2229   // It is callee save so it survives the call to native
2230 
2231   const Register oop_handle_reg = r14;
2232 
2233   if (is_critical_native && !Universe::heap()->supports_object_pinning()) {
2234     check_needs_gc_for_critical_native(masm, stack_slots, total_c_args, total_in_args,
2235                                        oop_handle_offset, oop_maps, in_regs, in_sig_bt);
2236   }
2237 
2238   //
2239   // We immediately shuffle the arguments so that any vm call we have to
2240   // make from here on out (sync slow path, jvmti, etc.) we will have
2241   // captured the oops from our caller and have a valid oopMap for
2242   // them.
2243 
2244   // -----------------
2245   // The Grand Shuffle
2246 
2247   // The Java calling convention is either equal (linux) or denser (win64) than the
2248   // c calling convention. However the because of the jni_env argument the c calling
2249   // convention always has at least one more (and two for static) arguments than Java.
2250   // Therefore if we move the args from java -> c backwards then we will never have
2251   // a register->register conflict and we don't have to build a dependency graph
2252   // and figure out how to break any cycles.
2253   //
2254 
2255   // Record esp-based slot for receiver on stack for non-static methods
2256   int receiver_offset = -1;
2257 
2258   // This is a trick. We double the stack slots so we can claim
2259   // the oops in the caller's frame. Since we are sure to have
2260   // more args than the caller doubling is enough to make
2261   // sure we can capture all the incoming oop args from the
2262   // caller.
2263   //
2264   OopMap* map = new OopMap(stack_slots * 2, 0 /* arg_slots*/);
2265 
2266   // Mark location of rbp (someday)
2267   // map->set_callee_saved(VMRegImpl::stack2reg( stack_slots - 2), stack_slots * 2, 0, vmreg(rbp));
2268 
2269   // Use eax, ebx as temporaries during any memory-memory moves we have to do
2270   // All inbound args are referenced based on rbp and all outbound args via rsp.
2271 
2272 
2273 #ifdef ASSERT
2274   bool reg_destroyed[RegisterImpl::number_of_registers];
2275   bool freg_destroyed[XMMRegisterImpl::number_of_registers];
2276   for ( int r = 0 ; r < RegisterImpl::number_of_registers ; r++ ) {
2277     reg_destroyed[r] = false;
2278   }
2279   for ( int f = 0 ; f < XMMRegisterImpl::number_of_registers ; f++ ) {
2280     freg_destroyed[f] = false;
2281   }
2282 
2283 #endif /* ASSERT */
2284 
2285   // This may iterate in two different directions depending on the
2286   // kind of native it is.  The reason is that for regular JNI natives
2287   // the incoming and outgoing registers are offset upwards and for
2288   // critical natives they are offset down.
2289   GrowableArray<int> arg_order(2 * total_in_args);
2290   // Inbound arguments that need to be pinned for critical natives
2291   GrowableArray<int> pinned_args(total_in_args);
2292   // Current stack slot for storing register based array argument
2293   int pinned_slot = oop_handle_offset;
2294 
2295   VMRegPair tmp_vmreg;
2296   tmp_vmreg.set2(rbx->as_VMReg());
2297 
2298   if (!is_critical_native) {
2299     for (int i = total_in_args - 1, c_arg = total_c_args - 1; i >= 0; i--, c_arg--) {
2300       arg_order.push(i);
2301       arg_order.push(c_arg);
2302     }
2303   } else {
2304     // Compute a valid move order, using tmp_vmreg to break any cycles
2305     ComputeMoveOrder cmo(total_in_args, in_regs, total_c_args, out_regs, in_sig_bt, arg_order, tmp_vmreg);
2306   }
2307 
2308   int temploc = -1;
2309   for (int ai = 0; ai < arg_order.length(); ai += 2) {
2310     int i = arg_order.at(ai);
2311     int c_arg = arg_order.at(ai + 1);
2312     __ block_comment(err_msg("move %d -> %d", i, c_arg));
2313     if (c_arg == -1) {
2314       assert(is_critical_native, "should only be required for critical natives");
2315       // This arg needs to be moved to a temporary
2316       __ mov(tmp_vmreg.first()->as_Register(), in_regs[i].first()->as_Register());
2317       in_regs[i] = tmp_vmreg;
2318       temploc = i;
2319       continue;
2320     } else if (i == -1) {
2321       assert(is_critical_native, "should only be required for critical natives");
2322       // Read from the temporary location
2323       assert(temploc != -1, "must be valid");
2324       i = temploc;
2325       temploc = -1;
2326     }
2327 #ifdef ASSERT
2328     if (in_regs[i].first()->is_Register()) {
2329       assert(!reg_destroyed[in_regs[i].first()->as_Register()->encoding()], "destroyed reg!");
2330     } else if (in_regs[i].first()->is_XMMRegister()) {
2331       assert(!freg_destroyed[in_regs[i].first()->as_XMMRegister()->encoding()], "destroyed reg!");
2332     }
2333     if (out_regs[c_arg].first()->is_Register()) {
2334       reg_destroyed[out_regs[c_arg].first()->as_Register()->encoding()] = true;
2335     } else if (out_regs[c_arg].first()->is_XMMRegister()) {
2336       freg_destroyed[out_regs[c_arg].first()->as_XMMRegister()->encoding()] = true;
2337     }
2338 #endif /* ASSERT */
2339     switch (in_sig_bt[i]) {
2340       case T_ARRAY:
2341         if (is_critical_native) {
2342           // pin before unpack
2343           if (Universe::heap()->supports_object_pinning()) {
2344             save_args(masm, total_c_args, 0, out_regs);
2345             gen_pin_object(masm, in_regs[i]);
2346             pinned_args.append(i);
2347             restore_args(masm, total_c_args, 0, out_regs);
2348 
2349             // rax has pinned array
2350             VMRegPair result_reg;
2351             result_reg.set_ptr(rax->as_VMReg());
2352             move_ptr(masm, result_reg, in_regs[i]);
2353             if (!in_regs[i].first()->is_stack()) {
2354               assert(pinned_slot <= stack_slots, "overflow");
2355               move_ptr(masm, result_reg, VMRegImpl::stack2reg(pinned_slot));
2356               pinned_slot += VMRegImpl::slots_per_word;
2357             }
2358           }
2359           unpack_array_argument(masm, in_regs[i], in_elem_bt[i], out_regs[c_arg + 1], out_regs[c_arg]);
2360           c_arg++;
2361 #ifdef ASSERT
2362           if (out_regs[c_arg].first()->is_Register()) {
2363             reg_destroyed[out_regs[c_arg].first()->as_Register()->encoding()] = true;
2364           } else if (out_regs[c_arg].first()->is_XMMRegister()) {
2365             freg_destroyed[out_regs[c_arg].first()->as_XMMRegister()->encoding()] = true;
2366           }
2367 #endif
2368           break;
2369         }
2370       case T_OBJECT:
2371         assert(!is_critical_native, "no oop arguments");
2372         object_move(masm, map, oop_handle_offset, stack_slots, in_regs[i], out_regs[c_arg],
2373                     ((i == 0) && (!is_static)),
2374                     &receiver_offset);
2375         break;
2376       case T_VOID:
2377         break;
2378 
2379       case T_FLOAT:
2380         float_move(masm, in_regs[i], out_regs[c_arg]);
2381           break;
2382 
2383       case T_DOUBLE:
2384         assert( i + 1 < total_in_args &&
2385                 in_sig_bt[i + 1] == T_VOID &&
2386                 out_sig_bt[c_arg+1] == T_VOID, "bad arg list");
2387         double_move(masm, in_regs[i], out_regs[c_arg]);
2388         break;
2389 
2390       case T_LONG :
2391         long_move(masm, in_regs[i], out_regs[c_arg]);
2392         break;
2393 
2394       case T_ADDRESS: assert(false, "found T_ADDRESS in java args");
2395 
2396       default:
2397         move32_64(masm, in_regs[i], out_regs[c_arg]);
2398     }
2399   }
2400 
2401   int c_arg;
2402 
2403   // Pre-load a static method's oop into r14.  Used both by locking code and
2404   // the normal JNI call code.
2405   if (!is_critical_native) {
2406     // point c_arg at the first arg that is already loaded in case we
2407     // need to spill before we call out
2408     c_arg = total_c_args - total_in_args;
2409 
2410     if (method->is_static()) {
2411 
2412       //  load oop into a register
2413       __ movoop(oop_handle_reg, JNIHandles::make_local(method->method_holder()->java_mirror()));
2414 
2415       // Now handlize the static class mirror it's known not-null.
2416       __ movptr(Address(rsp, klass_offset), oop_handle_reg);
2417       map->set_oop(VMRegImpl::stack2reg(klass_slot_offset));
2418 
2419       // Now get the handle
2420       __ lea(oop_handle_reg, Address(rsp, klass_offset));
2421       // store the klass handle as second argument
2422       __ movptr(c_rarg1, oop_handle_reg);
2423       // and protect the arg if we must spill
2424       c_arg--;
2425     }
2426   } else {
2427     // For JNI critical methods we need to save all registers in save_args.
2428     c_arg = 0;
2429   }
2430 
2431   // Change state to native (we save the return address in the thread, since it might not
2432   // be pushed on the stack when we do a a stack traversal). It is enough that the pc()
2433   // points into the right code segment. It does not have to be the correct return pc.
2434   // We use the same pc/oopMap repeatedly when we call out
2435 
2436   intptr_t the_pc = (intptr_t) __ pc();
2437   oop_maps->add_gc_map(the_pc - start, map);
2438 
2439   __ set_last_Java_frame(rsp, noreg, (address)the_pc);
2440 
2441 
2442   // We have all of the arguments setup at this point. We must not touch any register
2443   // argument registers at this point (what if we save/restore them there are no oop?
2444 
2445   {
2446     SkipIfEqual skip(masm, &DTraceMethodProbes, false);
2447     // protect the args we've loaded
2448     save_args(masm, total_c_args, c_arg, out_regs);
2449     __ mov_metadata(c_rarg1, method());
2450     __ call_VM_leaf(
2451       CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_entry),
2452       r15_thread, c_rarg1);
2453     restore_args(masm, total_c_args, c_arg, out_regs);
2454   }
2455 
2456   // RedefineClasses() tracing support for obsolete method entry
2457   if (log_is_enabled(Trace, redefine, class, obsolete)) {
2458     // protect the args we've loaded
2459     save_args(masm, total_c_args, c_arg, out_regs);
2460     __ mov_metadata(c_rarg1, method());
2461     __ call_VM_leaf(
2462       CAST_FROM_FN_PTR(address, SharedRuntime::rc_trace_method_entry),
2463       r15_thread, c_rarg1);
2464     restore_args(masm, total_c_args, c_arg, out_regs);
2465   }
2466 
2467   // Lock a synchronized method
2468 
2469   // Register definitions used by locking and unlocking
2470 
2471   const Register swap_reg = rax;  // Must use rax for cmpxchg instruction
2472   const Register obj_reg  = rbx;  // Will contain the oop
2473   const Register lock_reg = r13;  // Address of compiler lock object (BasicLock)
2474   const Register old_hdr  = r13;  // value of old header at unlock time
2475 
2476   Label slow_path_lock;
2477   Label lock_done;
2478 
2479   if (method->is_synchronized()) {
2480     assert(!is_critical_native, "unhandled");
2481 
2482 
2483     const int mark_word_offset = BasicLock::displaced_header_offset_in_bytes();
2484 
2485     // Get the handle (the 2nd argument)
2486     __ mov(oop_handle_reg, c_rarg1);
2487 
2488     // Get address of the box
2489 
2490     __ lea(lock_reg, Address(rsp, lock_slot_offset * VMRegImpl::stack_slot_size));
2491 
2492     // Load the oop from the handle
2493     __ movptr(obj_reg, Address(oop_handle_reg, 0));
2494 
2495     __ resolve(IS_NOT_NULL, obj_reg);
2496     if (UseBiasedLocking) {
2497       __ biased_locking_enter(lock_reg, obj_reg, swap_reg, rscratch1, false, lock_done, &slow_path_lock);
2498     }
2499 
2500     // Load immediate 1 into swap_reg %rax
2501     __ movl(swap_reg, 1);
2502 
2503     // Load (object->mark() | 1) into swap_reg %rax
2504     __ orptr(swap_reg, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
2505 
2506     // Save (object->mark() | 1) into BasicLock's displaced header
2507     __ movptr(Address(lock_reg, mark_word_offset), swap_reg);
2508 
2509     // src -> dest iff dest == rax else rax <- dest
2510     __ lock();
2511     __ cmpxchgptr(lock_reg, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
2512     __ jcc(Assembler::equal, lock_done);
2513 
2514     // Hmm should this move to the slow path code area???
2515 
2516     // Test if the oopMark is an obvious stack pointer, i.e.,
2517     //  1) (mark & 3) == 0, and
2518     //  2) rsp <= mark < mark + os::pagesize()
2519     // These 3 tests can be done by evaluating the following
2520     // expression: ((mark - rsp) & (3 - os::vm_page_size())),
2521     // assuming both stack pointer and pagesize have their
2522     // least significant 2 bits clear.
2523     // NOTE: the oopMark is in swap_reg %rax as the result of cmpxchg
2524 
2525     __ subptr(swap_reg, rsp);
2526     __ andptr(swap_reg, 3 - os::vm_page_size());
2527 
2528     // Save the test result, for recursive case, the result is zero
2529     __ movptr(Address(lock_reg, mark_word_offset), swap_reg);
2530     __ jcc(Assembler::notEqual, slow_path_lock);
2531 
2532     // Slow path will re-enter here
2533 
2534     __ bind(lock_done);
2535   }
2536 
2537 
2538   // Finally just about ready to make the JNI call
2539 
2540 
2541   // get JNIEnv* which is first argument to native
2542   if (!is_critical_native) {
2543     __ lea(c_rarg0, Address(r15_thread, in_bytes(JavaThread::jni_environment_offset())));
2544   }
2545 
2546   // Now set thread in native
2547   __ movl(Address(r15_thread, JavaThread::thread_state_offset()), _thread_in_native);
2548 
2549   __ call(RuntimeAddress(native_func));
2550 
2551   // Verify or restore cpu control state after JNI call
2552   __ restore_cpu_control_state_after_jni();
2553 
2554   // Unpack native results.
2555   switch (ret_type) {
2556   case T_BOOLEAN: __ c2bool(rax);            break;
2557   case T_CHAR   : __ movzwl(rax, rax);      break;
2558   case T_BYTE   : __ sign_extend_byte (rax); break;
2559   case T_SHORT  : __ sign_extend_short(rax); break;
2560   case T_INT    : /* nothing to do */        break;
2561   case T_DOUBLE :
2562   case T_FLOAT  :
2563     // Result is in xmm0 we'll save as needed
2564     break;
2565   case T_ARRAY:                 // Really a handle
2566   case T_OBJECT:                // Really a handle
2567       break; // can't de-handlize until after safepoint check
2568   case T_VOID: break;
2569   case T_LONG: break;
2570   default       : ShouldNotReachHere();
2571   }
2572 
2573   // unpin pinned arguments
2574   pinned_slot = oop_handle_offset;
2575   if (pinned_args.length() > 0) {
2576     // save return value that may be overwritten otherwise.
2577     save_native_result(masm, ret_type, stack_slots);
2578     for (int index = 0; index < pinned_args.length(); index ++) {
2579       int i = pinned_args.at(index);
2580       assert(pinned_slot <= stack_slots, "overflow");
2581       if (!in_regs[i].first()->is_stack()) {
2582         int offset = pinned_slot * VMRegImpl::stack_slot_size;
2583         __ movq(in_regs[i].first()->as_Register(), Address(rsp, offset));
2584         pinned_slot += VMRegImpl::slots_per_word;
2585       }
2586       gen_unpin_object(masm, in_regs[i]);
2587     }
2588     restore_native_result(masm, ret_type, stack_slots);
2589   }
2590 
2591   // Switch thread to "native transition" state before reading the synchronization state.
2592   // This additional state is necessary because reading and testing the synchronization
2593   // state is not atomic w.r.t. GC, as this scenario demonstrates:
2594   //     Java thread A, in _thread_in_native state, loads _not_synchronized and is preempted.
2595   //     VM thread changes sync state to synchronizing and suspends threads for GC.
2596   //     Thread A is resumed to finish this native method, but doesn't block here since it
2597   //     didn't see any synchronization is progress, and escapes.
2598   __ movl(Address(r15_thread, JavaThread::thread_state_offset()), _thread_in_native_trans);
2599 
2600   // Force this write out before the read below
2601   __ membar(Assembler::Membar_mask_bits(
2602               Assembler::LoadLoad | Assembler::LoadStore |
2603               Assembler::StoreLoad | Assembler::StoreStore));
2604 
2605   Label after_transition;
2606 
2607   // check for safepoint operation in progress and/or pending suspend requests
2608   {
2609     Label Continue;
2610     Label slow_path;
2611 
2612     __ safepoint_poll(slow_path, r15_thread, rscratch1);
2613 
2614     __ cmpl(Address(r15_thread, JavaThread::suspend_flags_offset()), 0);
2615     __ jcc(Assembler::equal, Continue);
2616     __ bind(slow_path);
2617 
2618     // Don't use call_VM as it will see a possible pending exception and forward it
2619     // and never return here preventing us from clearing _last_native_pc down below.
2620     // Also can't use call_VM_leaf either as it will check to see if rsi & rdi are
2621     // preserved and correspond to the bcp/locals pointers. So we do a runtime call
2622     // by hand.
2623     //
2624     __ vzeroupper();
2625     save_native_result(masm, ret_type, stack_slots);
2626     __ mov(c_rarg0, r15_thread);
2627     __ mov(r12, rsp); // remember sp
2628     __ subptr(rsp, frame::arg_reg_save_area_bytes); // windows
2629     __ andptr(rsp, -16); // align stack as required by ABI
2630     if (!is_critical_native) {
2631       __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, JavaThread::check_special_condition_for_native_trans)));
2632     } else {
2633       __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, JavaThread::check_special_condition_for_native_trans_and_transition)));
2634     }
2635     __ mov(rsp, r12); // restore sp
2636     __ reinit_heapbase();
2637     // Restore any method result value
2638     restore_native_result(masm, ret_type, stack_slots);
2639 
2640     if (is_critical_native) {
2641       // The call above performed the transition to thread_in_Java so
2642       // skip the transition logic below.
2643       __ jmpb(after_transition);
2644     }
2645 
2646     __ bind(Continue);
2647   }
2648 
2649   // change thread state
2650   __ movl(Address(r15_thread, JavaThread::thread_state_offset()), _thread_in_Java);
2651   __ bind(after_transition);
2652 
2653   Label reguard;
2654   Label reguard_done;
2655   __ cmpl(Address(r15_thread, JavaThread::stack_guard_state_offset()), JavaThread::stack_guard_yellow_reserved_disabled);
2656   __ jcc(Assembler::equal, reguard);
2657   __ bind(reguard_done);
2658 
2659   // native result if any is live
2660 
2661   // Unlock
2662   Label unlock_done;
2663   Label slow_path_unlock;
2664   if (method->is_synchronized()) {
2665 
2666     // Get locked oop from the handle we passed to jni
2667     __ movptr(obj_reg, Address(oop_handle_reg, 0));
2668     __ resolve(IS_NOT_NULL, obj_reg);
2669 
2670     Label done;
2671 
2672     if (UseBiasedLocking) {
2673       __ biased_locking_exit(obj_reg, old_hdr, done);
2674     }
2675 
2676     // Simple recursive lock?
2677 
2678     __ cmpptr(Address(rsp, lock_slot_offset * VMRegImpl::stack_slot_size), (int32_t)NULL_WORD);
2679     __ jcc(Assembler::equal, done);
2680 
2681     // Must save rax if if it is live now because cmpxchg must use it
2682     if (ret_type != T_FLOAT && ret_type != T_DOUBLE && ret_type != T_VOID) {
2683       save_native_result(masm, ret_type, stack_slots);
2684     }
2685 
2686 
2687     // get address of the stack lock
2688     __ lea(rax, Address(rsp, lock_slot_offset * VMRegImpl::stack_slot_size));
2689     //  get old displaced header
2690     __ movptr(old_hdr, Address(rax, 0));
2691 
2692     // Atomic swap old header if oop still contains the stack lock
2693     __ lock();
2694     __ cmpxchgptr(old_hdr, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
2695     __ jcc(Assembler::notEqual, slow_path_unlock);
2696 
2697     // slow path re-enters here
2698     __ bind(unlock_done);
2699     if (ret_type != T_FLOAT && ret_type != T_DOUBLE && ret_type != T_VOID) {
2700       restore_native_result(masm, ret_type, stack_slots);
2701     }
2702 
2703     __ bind(done);
2704 
2705   }
2706   {
2707     SkipIfEqual skip(masm, &DTraceMethodProbes, false);
2708     save_native_result(masm, ret_type, stack_slots);
2709     __ mov_metadata(c_rarg1, method());
2710     __ call_VM_leaf(
2711          CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_exit),
2712          r15_thread, c_rarg1);
2713     restore_native_result(masm, ret_type, stack_slots);
2714   }
2715 
2716   __ reset_last_Java_frame(false);
2717 
2718   // Unbox oop result, e.g. JNIHandles::resolve value.
2719   if (is_reference_type(ret_type)) {
2720     __ resolve_jobject(rax /* value */,
2721                        r15_thread /* thread */,
2722                        rcx /* tmp */);
2723   }
2724 
2725   if (CheckJNICalls) {
2726     // clear_pending_jni_exception_check
2727     __ movptr(Address(r15_thread, JavaThread::pending_jni_exception_check_fn_offset()), NULL_WORD);
2728   }
2729 
2730   if (!is_critical_native) {
2731     // reset handle block
2732     __ movptr(rcx, Address(r15_thread, JavaThread::active_handles_offset()));
2733     __ movl(Address(rcx, JNIHandleBlock::top_offset_in_bytes()), (int32_t)NULL_WORD);
2734   }
2735 
2736   // pop our frame
2737 
2738   __ leave();
2739 
2740   if (!is_critical_native) {
2741     // Any exception pending?
2742     __ cmpptr(Address(r15_thread, in_bytes(Thread::pending_exception_offset())), (int32_t)NULL_WORD);
2743     __ jcc(Assembler::notEqual, exception_pending);
2744   }
2745 
2746   // Return
2747 
2748   __ ret(0);
2749 
2750   // Unexpected paths are out of line and go here
2751 
2752   if (!is_critical_native) {
2753     // forward the exception
2754     __ bind(exception_pending);
2755 
2756     // and forward the exception
2757     __ jump(RuntimeAddress(StubRoutines::forward_exception_entry()));
2758   }
2759 
2760   // Slow path locking & unlocking
2761   if (method->is_synchronized()) {
2762 
2763     // BEGIN Slow path lock
2764     __ bind(slow_path_lock);
2765 
2766     // has last_Java_frame setup. No exceptions so do vanilla call not call_VM
2767     // args are (oop obj, BasicLock* lock, JavaThread* thread)
2768 
2769     // protect the args we've loaded
2770     save_args(masm, total_c_args, c_arg, out_regs);
2771 
2772     __ mov(c_rarg0, obj_reg);
2773     __ mov(c_rarg1, lock_reg);
2774     __ mov(c_rarg2, r15_thread);
2775 
2776     // Not a leaf but we have last_Java_frame setup as we want
2777     __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_locking_C), 3);
2778     restore_args(masm, total_c_args, c_arg, out_regs);
2779 
2780 #ifdef ASSERT
2781     { Label L;
2782     __ cmpptr(Address(r15_thread, in_bytes(Thread::pending_exception_offset())), (int32_t)NULL_WORD);
2783     __ jcc(Assembler::equal, L);
2784     __ stop("no pending exception allowed on exit from monitorenter");
2785     __ bind(L);
2786     }
2787 #endif
2788     __ jmp(lock_done);
2789 
2790     // END Slow path lock
2791 
2792     // BEGIN Slow path unlock
2793     __ bind(slow_path_unlock);
2794 
2795     // If we haven't already saved the native result we must save it now as xmm registers
2796     // are still exposed.
2797     __ vzeroupper();
2798     if (ret_type == T_FLOAT || ret_type == T_DOUBLE ) {
2799       save_native_result(masm, ret_type, stack_slots);
2800     }
2801 
2802     __ lea(c_rarg1, Address(rsp, lock_slot_offset * VMRegImpl::stack_slot_size));
2803 
2804     __ mov(c_rarg0, obj_reg);
2805     __ mov(c_rarg2, r15_thread);
2806     __ mov(r12, rsp); // remember sp
2807     __ subptr(rsp, frame::arg_reg_save_area_bytes); // windows
2808     __ andptr(rsp, -16); // align stack as required by ABI
2809 
2810     // Save pending exception around call to VM (which contains an EXCEPTION_MARK)
2811     // NOTE that obj_reg == rbx currently
2812     __ movptr(rbx, Address(r15_thread, in_bytes(Thread::pending_exception_offset())));
2813     __ movptr(Address(r15_thread, in_bytes(Thread::pending_exception_offset())), (int32_t)NULL_WORD);
2814 
2815     // args are (oop obj, BasicLock* lock, JavaThread* thread)
2816     __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_unlocking_C)));
2817     __ mov(rsp, r12); // restore sp
2818     __ reinit_heapbase();
2819 #ifdef ASSERT
2820     {
2821       Label L;
2822       __ cmpptr(Address(r15_thread, in_bytes(Thread::pending_exception_offset())), (int)NULL_WORD);
2823       __ jcc(Assembler::equal, L);
2824       __ stop("no pending exception allowed on exit complete_monitor_unlocking_C");
2825       __ bind(L);
2826     }
2827 #endif /* ASSERT */
2828 
2829     __ movptr(Address(r15_thread, in_bytes(Thread::pending_exception_offset())), rbx);
2830 
2831     if (ret_type == T_FLOAT || ret_type == T_DOUBLE ) {
2832       restore_native_result(masm, ret_type, stack_slots);
2833     }
2834     __ jmp(unlock_done);
2835 
2836     // END Slow path unlock
2837 
2838   } // synchronized
2839 
2840   // SLOW PATH Reguard the stack if needed
2841 
2842   __ bind(reguard);
2843   __ vzeroupper();
2844   save_native_result(masm, ret_type, stack_slots);
2845   __ mov(r12, rsp); // remember sp
2846   __ subptr(rsp, frame::arg_reg_save_area_bytes); // windows
2847   __ andptr(rsp, -16); // align stack as required by ABI
2848   __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, SharedRuntime::reguard_yellow_pages)));
2849   __ mov(rsp, r12); // restore sp
2850   __ reinit_heapbase();
2851   restore_native_result(masm, ret_type, stack_slots);
2852   // and continue
2853   __ jmp(reguard_done);
2854 
2855 
2856 
2857   __ flush();
2858 
2859   nmethod *nm = nmethod::new_native_nmethod(method,
2860                                             compile_id,
2861                                             masm->code(),
2862                                             vep_offset,
2863                                             frame_complete,
2864                                             stack_slots / VMRegImpl::slots_per_word,
2865                                             (is_static ? in_ByteSize(klass_offset) : in_ByteSize(receiver_offset)),
2866                                             in_ByteSize(lock_slot_offset*VMRegImpl::stack_slot_size),
2867                                             oop_maps);
2868 
2869   if (is_critical_native) {
2870     nm->set_lazy_critical_native(true);
2871   }
2872 
2873   return nm;
2874 
2875 }
2876 
2877 // this function returns the adjust size (in number of words) to a c2i adapter
2878 // activation for use during deoptimization
2879 int Deoptimization::last_frame_adjust(int callee_parameters, int callee_locals ) {
2880   return (callee_locals - callee_parameters) * Interpreter::stackElementWords;
2881 }
2882 
2883 
2884 uint SharedRuntime::out_preserve_stack_slots() {
2885   return 0;
2886 }
2887 
2888 //------------------------------generate_deopt_blob----------------------------
2889 void SharedRuntime::generate_deopt_blob() {
2890   // Allocate space for the code
2891   ResourceMark rm;
2892   // Setup code generation tools
2893   int pad = 0;
2894 #if INCLUDE_JVMCI
2895   if (EnableJVMCI || UseAOT) {
2896     pad += 512; // Increase the buffer size when compiling for JVMCI
2897   }
2898 #endif
2899   CodeBuffer buffer("deopt_blob", 2048+pad, 1024);
2900   MacroAssembler* masm = new MacroAssembler(&buffer);
2901   int frame_size_in_words;
2902   OopMap* map = NULL;
2903   OopMapSet *oop_maps = new OopMapSet();
2904 
2905   // -------------
2906   // This code enters when returning to a de-optimized nmethod.  A return
2907   // address has been pushed on the the stack, and return values are in
2908   // registers.
2909   // If we are doing a normal deopt then we were called from the patched
2910   // nmethod from the point we returned to the nmethod. So the return
2911   // address on the stack is wrong by NativeCall::instruction_size
2912   // We will adjust the value so it looks like we have the original return
2913   // address on the stack (like when we eagerly deoptimized).
2914   // In the case of an exception pending when deoptimizing, we enter
2915   // with a return address on the stack that points after the call we patched
2916   // into the exception handler. We have the following register state from,
2917   // e.g., the forward exception stub (see stubGenerator_x86_64.cpp).
2918   //    rax: exception oop
2919   //    rbx: exception handler
2920   //    rdx: throwing pc
2921   // So in this case we simply jam rdx into the useless return address and
2922   // the stack looks just like we want.
2923   //
2924   // At this point we need to de-opt.  We save the argument return
2925   // registers.  We call the first C routine, fetch_unroll_info().  This
2926   // routine captures the return values and returns a structure which
2927   // describes the current frame size and the sizes of all replacement frames.
2928   // The current frame is compiled code and may contain many inlined
2929   // functions, each with their own JVM state.  We pop the current frame, then
2930   // push all the new frames.  Then we call the C routine unpack_frames() to
2931   // populate these frames.  Finally unpack_frames() returns us the new target
2932   // address.  Notice that callee-save registers are BLOWN here; they have
2933   // already been captured in the vframeArray at the time the return PC was
2934   // patched.
2935   address start = __ pc();
2936   Label cont;
2937 
2938   // Prolog for non exception case!
2939 
2940   // Save everything in sight.
2941   map = RegisterSaver::save_live_registers(masm, 0, &frame_size_in_words);
2942 
2943   // Normal deoptimization.  Save exec mode for unpack_frames.
2944   __ movl(r14, Deoptimization::Unpack_deopt); // callee-saved
2945   __ jmp(cont);
2946 
2947   int reexecute_offset = __ pc() - start;
2948 #if INCLUDE_JVMCI && !defined(COMPILER1)
2949   if (EnableJVMCI && UseJVMCICompiler) {
2950     // JVMCI does not use this kind of deoptimization
2951     __ should_not_reach_here();
2952   }
2953 #endif
2954 
2955   // Reexecute case
2956   // return address is the pc describes what bci to do re-execute at
2957 
2958   // No need to update map as each call to save_live_registers will produce identical oopmap
2959   (void) RegisterSaver::save_live_registers(masm, 0, &frame_size_in_words);
2960 
2961   __ movl(r14, Deoptimization::Unpack_reexecute); // callee-saved
2962   __ jmp(cont);
2963 
2964 #if INCLUDE_JVMCI
2965   Label after_fetch_unroll_info_call;
2966   int implicit_exception_uncommon_trap_offset = 0;
2967   int uncommon_trap_offset = 0;
2968 
2969   if (EnableJVMCI || UseAOT) {
2970     implicit_exception_uncommon_trap_offset = __ pc() - start;
2971 
2972     __ pushptr(Address(r15_thread, in_bytes(JavaThread::jvmci_implicit_exception_pc_offset())));
2973     __ movptr(Address(r15_thread, in_bytes(JavaThread::jvmci_implicit_exception_pc_offset())), (int32_t)NULL_WORD);
2974 
2975     uncommon_trap_offset = __ pc() - start;
2976 
2977     // Save everything in sight.
2978     RegisterSaver::save_live_registers(masm, 0, &frame_size_in_words);
2979     // fetch_unroll_info needs to call last_java_frame()
2980     __ set_last_Java_frame(noreg, noreg, NULL);
2981 
2982     __ movl(c_rarg1, Address(r15_thread, in_bytes(JavaThread::pending_deoptimization_offset())));
2983     __ movl(Address(r15_thread, in_bytes(JavaThread::pending_deoptimization_offset())), -1);
2984 
2985     __ movl(r14, (int32_t)Deoptimization::Unpack_reexecute);
2986     __ mov(c_rarg0, r15_thread);
2987     __ movl(c_rarg2, r14); // exec mode
2988     __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, Deoptimization::uncommon_trap)));
2989     oop_maps->add_gc_map( __ pc()-start, map->deep_copy());
2990 
2991     __ reset_last_Java_frame(false);
2992 
2993     __ jmp(after_fetch_unroll_info_call);
2994   } // EnableJVMCI
2995 #endif // INCLUDE_JVMCI
2996 
2997   int exception_offset = __ pc() - start;
2998 
2999   // Prolog for exception case
3000 
3001   // all registers are dead at this entry point, except for rax, and
3002   // rdx which contain the exception oop and exception pc
3003   // respectively.  Set them in TLS and fall thru to the
3004   // unpack_with_exception_in_tls entry point.
3005 
3006   __ movptr(Address(r15_thread, JavaThread::exception_pc_offset()), rdx);
3007   __ movptr(Address(r15_thread, JavaThread::exception_oop_offset()), rax);
3008 
3009   int exception_in_tls_offset = __ pc() - start;
3010 
3011   // new implementation because exception oop is now passed in JavaThread
3012 
3013   // Prolog for exception case
3014   // All registers must be preserved because they might be used by LinearScan
3015   // Exceptiop oop and throwing PC are passed in JavaThread
3016   // tos: stack at point of call to method that threw the exception (i.e. only
3017   // args are on the stack, no return address)
3018 
3019   // make room on stack for the return address
3020   // It will be patched later with the throwing pc. The correct value is not
3021   // available now because loading it from memory would destroy registers.
3022   __ push(0);
3023 
3024   // Save everything in sight.
3025   map = RegisterSaver::save_live_registers(masm, 0, &frame_size_in_words);
3026 
3027   // Now it is safe to overwrite any register
3028 
3029   // Deopt during an exception.  Save exec mode for unpack_frames.
3030   __ movl(r14, Deoptimization::Unpack_exception); // callee-saved
3031 
3032   // load throwing pc from JavaThread and patch it as the return address
3033   // of the current frame. Then clear the field in JavaThread
3034 
3035   __ movptr(rdx, Address(r15_thread, JavaThread::exception_pc_offset()));
3036   __ movptr(Address(rbp, wordSize), rdx);
3037   __ movptr(Address(r15_thread, JavaThread::exception_pc_offset()), (int32_t)NULL_WORD);
3038 
3039 #ifdef ASSERT
3040   // verify that there is really an exception oop in JavaThread
3041   __ movptr(rax, Address(r15_thread, JavaThread::exception_oop_offset()));
3042   __ verify_oop(rax);
3043 
3044   // verify that there is no pending exception
3045   Label no_pending_exception;
3046   __ movptr(rax, Address(r15_thread, Thread::pending_exception_offset()));
3047   __ testptr(rax, rax);
3048   __ jcc(Assembler::zero, no_pending_exception);
3049   __ stop("must not have pending exception here");
3050   __ bind(no_pending_exception);
3051 #endif
3052 
3053   __ bind(cont);
3054 
3055   // Call C code.  Need thread and this frame, but NOT official VM entry
3056   // crud.  We cannot block on this call, no GC can happen.
3057   //
3058   // UnrollBlock* fetch_unroll_info(JavaThread* thread)
3059 
3060   // fetch_unroll_info needs to call last_java_frame().
3061 
3062   __ set_last_Java_frame(noreg, noreg, NULL);
3063 #ifdef ASSERT
3064   { Label L;
3065     __ cmpptr(Address(r15_thread,
3066                     JavaThread::last_Java_fp_offset()),
3067             (int32_t)0);
3068     __ jcc(Assembler::equal, L);
3069     __ stop("SharedRuntime::generate_deopt_blob: last_Java_fp not cleared");
3070     __ bind(L);
3071   }
3072 #endif // ASSERT
3073   __ mov(c_rarg0, r15_thread);
3074   __ movl(c_rarg1, r14); // exec_mode
3075   __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, Deoptimization::fetch_unroll_info)));
3076 
3077   // Need to have an oopmap that tells fetch_unroll_info where to
3078   // find any register it might need.
3079   oop_maps->add_gc_map(__ pc() - start, map);
3080 
3081   __ reset_last_Java_frame(false);
3082 
3083 #if INCLUDE_JVMCI
3084   if (EnableJVMCI || UseAOT) {
3085     __ bind(after_fetch_unroll_info_call);
3086   }
3087 #endif
3088 
3089   // Load UnrollBlock* into rdi
3090   __ mov(rdi, rax);
3091 
3092   __ movl(r14, Address(rdi, Deoptimization::UnrollBlock::unpack_kind_offset_in_bytes()));
3093    Label noException;
3094   __ cmpl(r14, Deoptimization::Unpack_exception);   // Was exception pending?
3095   __ jcc(Assembler::notEqual, noException);
3096   __ movptr(rax, Address(r15_thread, JavaThread::exception_oop_offset()));
3097   // QQQ this is useless it was NULL above
3098   __ movptr(rdx, Address(r15_thread, JavaThread::exception_pc_offset()));
3099   __ movptr(Address(r15_thread, JavaThread::exception_oop_offset()), (int32_t)NULL_WORD);
3100   __ movptr(Address(r15_thread, JavaThread::exception_pc_offset()), (int32_t)NULL_WORD);
3101 
3102   __ verify_oop(rax);
3103 
3104   // Overwrite the result registers with the exception results.
3105   __ movptr(Address(rsp, RegisterSaver::rax_offset_in_bytes()), rax);
3106   // I think this is useless
3107   __ movptr(Address(rsp, RegisterSaver::rdx_offset_in_bytes()), rdx);
3108 
3109   __ bind(noException);
3110 
3111   // Only register save data is on the stack.
3112   // Now restore the result registers.  Everything else is either dead
3113   // or captured in the vframeArray.
3114   RegisterSaver::restore_result_registers(masm);
3115 
3116   // All of the register save area has been popped of the stack. Only the
3117   // return address remains.
3118 
3119   // Pop all the frames we must move/replace.
3120   //
3121   // Frame picture (youngest to oldest)
3122   // 1: self-frame (no frame link)
3123   // 2: deopting frame  (no frame link)
3124   // 3: caller of deopting frame (could be compiled/interpreted).
3125   //
3126   // Note: by leaving the return address of self-frame on the stack
3127   // and using the size of frame 2 to adjust the stack
3128   // when we are done the return to frame 3 will still be on the stack.
3129 
3130   // Pop deoptimized frame
3131   __ movl(rcx, Address(rdi, Deoptimization::UnrollBlock::size_of_deoptimized_frame_offset_in_bytes()));
3132   __ addptr(rsp, rcx);
3133 
3134   // rsp should be pointing at the return address to the caller (3)
3135 
3136   // Pick up the initial fp we should save
3137   // restore rbp before stack bang because if stack overflow is thrown it needs to be pushed (and preserved)
3138   __ movptr(rbp, Address(rdi, Deoptimization::UnrollBlock::initial_info_offset_in_bytes()));
3139 
3140 #ifdef ASSERT
3141   // Compilers generate code that bang the stack by as much as the
3142   // interpreter would need. So this stack banging should never
3143   // trigger a fault. Verify that it does not on non product builds.
3144   if (UseStackBanging) {
3145     __ movl(rbx, Address(rdi, Deoptimization::UnrollBlock::total_frame_sizes_offset_in_bytes()));
3146     __ bang_stack_size(rbx, rcx);
3147   }
3148 #endif
3149 
3150   // Load address of array of frame pcs into rcx
3151   __ movptr(rcx, Address(rdi, Deoptimization::UnrollBlock::frame_pcs_offset_in_bytes()));
3152 
3153   // Trash the old pc
3154   __ addptr(rsp, wordSize);
3155 
3156   // Load address of array of frame sizes into rsi
3157   __ movptr(rsi, Address(rdi, Deoptimization::UnrollBlock::frame_sizes_offset_in_bytes()));
3158 
3159   // Load counter into rdx
3160   __ movl(rdx, Address(rdi, Deoptimization::UnrollBlock::number_of_frames_offset_in_bytes()));
3161 
3162   // Now adjust the caller's stack to make up for the extra locals
3163   // but record the original sp so that we can save it in the skeletal interpreter
3164   // frame and the stack walking of interpreter_sender will get the unextended sp
3165   // value and not the "real" sp value.
3166 
3167   const Register sender_sp = r8;
3168 
3169   __ mov(sender_sp, rsp);
3170   __ movl(rbx, Address(rdi,
3171                        Deoptimization::UnrollBlock::
3172                        caller_adjustment_offset_in_bytes()));
3173   __ subptr(rsp, rbx);
3174 
3175   // Push interpreter frames in a loop
3176   Label loop;
3177   __ bind(loop);
3178   __ movptr(rbx, Address(rsi, 0));      // Load frame size
3179   __ subptr(rbx, 2*wordSize);           // We'll push pc and ebp by hand
3180   __ pushptr(Address(rcx, 0));          // Save return address
3181   __ enter();                           // Save old & set new ebp
3182   __ subptr(rsp, rbx);                  // Prolog
3183   // This value is corrected by layout_activation_impl
3184   __ movptr(Address(rbp, frame::interpreter_frame_last_sp_offset * wordSize), (int32_t)NULL_WORD );
3185   __ movptr(Address(rbp, frame::interpreter_frame_sender_sp_offset * wordSize), sender_sp); // Make it walkable
3186   __ mov(sender_sp, rsp);               // Pass sender_sp to next frame
3187   __ addptr(rsi, wordSize);             // Bump array pointer (sizes)
3188   __ addptr(rcx, wordSize);             // Bump array pointer (pcs)
3189   __ decrementl(rdx);                   // Decrement counter
3190   __ jcc(Assembler::notZero, loop);
3191   __ pushptr(Address(rcx, 0));          // Save final return address
3192 
3193   // Re-push self-frame
3194   __ enter();                           // Save old & set new ebp
3195 
3196   // Allocate a full sized register save area.
3197   // Return address and rbp are in place, so we allocate two less words.
3198   __ subptr(rsp, (frame_size_in_words - 2) * wordSize);
3199 
3200   // Restore frame locals after moving the frame
3201   __ movdbl(Address(rsp, RegisterSaver::xmm0_offset_in_bytes()), xmm0);
3202   __ movptr(Address(rsp, RegisterSaver::rax_offset_in_bytes()), rax);
3203 
3204   // Call C code.  Need thread but NOT official VM entry
3205   // crud.  We cannot block on this call, no GC can happen.  Call should
3206   // restore return values to their stack-slots with the new SP.
3207   //
3208   // void Deoptimization::unpack_frames(JavaThread* thread, int exec_mode)
3209 
3210   // Use rbp because the frames look interpreted now
3211   // Save "the_pc" since it cannot easily be retrieved using the last_java_SP after we aligned SP.
3212   // Don't need the precise return PC here, just precise enough to point into this code blob.
3213   address the_pc = __ pc();
3214   __ set_last_Java_frame(noreg, rbp, the_pc);
3215 
3216   __ andptr(rsp, -(StackAlignmentInBytes));  // Fix stack alignment as required by ABI
3217   __ mov(c_rarg0, r15_thread);
3218   __ movl(c_rarg1, r14); // second arg: exec_mode
3219   __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, Deoptimization::unpack_frames)));
3220   // Revert SP alignment after call since we're going to do some SP relative addressing below
3221   __ movptr(rsp, Address(r15_thread, JavaThread::last_Java_sp_offset()));
3222 
3223   // Set an oopmap for the call site
3224   // Use the same PC we used for the last java frame
3225   oop_maps->add_gc_map(the_pc - start,
3226                        new OopMap( frame_size_in_words, 0 ));
3227 
3228   // Clear fp AND pc
3229   __ reset_last_Java_frame(true);
3230 
3231   // Collect return values
3232   __ movdbl(xmm0, Address(rsp, RegisterSaver::xmm0_offset_in_bytes()));
3233   __ movptr(rax, Address(rsp, RegisterSaver::rax_offset_in_bytes()));
3234   // I think this is useless (throwing pc?)
3235   __ movptr(rdx, Address(rsp, RegisterSaver::rdx_offset_in_bytes()));
3236 
3237   // Pop self-frame.
3238   __ leave();                           // Epilog
3239 
3240   // Jump to interpreter
3241   __ ret(0);
3242 
3243   // Make sure all code is generated
3244   masm->flush();
3245 
3246   _deopt_blob = DeoptimizationBlob::create(&buffer, oop_maps, 0, exception_offset, reexecute_offset, frame_size_in_words);
3247   _deopt_blob->set_unpack_with_exception_in_tls_offset(exception_in_tls_offset);
3248 #if INCLUDE_JVMCI
3249   if (EnableJVMCI || UseAOT) {
3250     _deopt_blob->set_uncommon_trap_offset(uncommon_trap_offset);
3251     _deopt_blob->set_implicit_exception_uncommon_trap_offset(implicit_exception_uncommon_trap_offset);
3252   }
3253 #endif
3254 }
3255 
3256 #ifdef COMPILER2
3257 //------------------------------generate_uncommon_trap_blob--------------------
3258 void SharedRuntime::generate_uncommon_trap_blob() {
3259   // Allocate space for the code
3260   ResourceMark rm;
3261   // Setup code generation tools
3262   CodeBuffer buffer("uncommon_trap_blob", 2048, 1024);
3263   MacroAssembler* masm = new MacroAssembler(&buffer);
3264 
3265   assert(SimpleRuntimeFrame::framesize % 4 == 0, "sp not 16-byte aligned");
3266 
3267   address start = __ pc();
3268 
3269   if (UseRTMLocking) {
3270     // Abort RTM transaction before possible nmethod deoptimization.
3271     __ xabort(0);
3272   }
3273 
3274   // Push self-frame.  We get here with a return address on the
3275   // stack, so rsp is 8-byte aligned until we allocate our frame.
3276   __ subptr(rsp, SimpleRuntimeFrame::return_off << LogBytesPerInt); // Epilog!
3277 
3278   // No callee saved registers. rbp is assumed implicitly saved
3279   __ movptr(Address(rsp, SimpleRuntimeFrame::rbp_off << LogBytesPerInt), rbp);
3280 
3281   // compiler left unloaded_class_index in j_rarg0 move to where the
3282   // runtime expects it.
3283   __ movl(c_rarg1, j_rarg0);
3284 
3285   __ set_last_Java_frame(noreg, noreg, NULL);
3286 
3287   // Call C code.  Need thread but NOT official VM entry
3288   // crud.  We cannot block on this call, no GC can happen.  Call should
3289   // capture callee-saved registers as well as return values.
3290   // Thread is in rdi already.
3291   //
3292   // UnrollBlock* uncommon_trap(JavaThread* thread, jint unloaded_class_index);
3293 
3294   __ mov(c_rarg0, r15_thread);
3295   __ movl(c_rarg2, Deoptimization::Unpack_uncommon_trap);
3296   __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, Deoptimization::uncommon_trap)));
3297 
3298   // Set an oopmap for the call site
3299   OopMapSet* oop_maps = new OopMapSet();
3300   OopMap* map = new OopMap(SimpleRuntimeFrame::framesize, 0);
3301 
3302   // location of rbp is known implicitly by the frame sender code
3303 
3304   oop_maps->add_gc_map(__ pc() - start, map);
3305 
3306   __ reset_last_Java_frame(false);
3307 
3308   // Load UnrollBlock* into rdi
3309   __ mov(rdi, rax);
3310 
3311 #ifdef ASSERT
3312   { Label L;
3313     __ cmpptr(Address(rdi, Deoptimization::UnrollBlock::unpack_kind_offset_in_bytes()),
3314             (int32_t)Deoptimization::Unpack_uncommon_trap);
3315     __ jcc(Assembler::equal, L);
3316     __ stop("SharedRuntime::generate_deopt_blob: expected Unpack_uncommon_trap");
3317     __ bind(L);
3318   }
3319 #endif
3320 
3321   // Pop all the frames we must move/replace.
3322   //
3323   // Frame picture (youngest to oldest)
3324   // 1: self-frame (no frame link)
3325   // 2: deopting frame  (no frame link)
3326   // 3: caller of deopting frame (could be compiled/interpreted).
3327 
3328   // Pop self-frame.  We have no frame, and must rely only on rax and rsp.
3329   __ addptr(rsp, (SimpleRuntimeFrame::framesize - 2) << LogBytesPerInt); // Epilog!
3330 
3331   // Pop deoptimized frame (int)
3332   __ movl(rcx, Address(rdi,
3333                        Deoptimization::UnrollBlock::
3334                        size_of_deoptimized_frame_offset_in_bytes()));
3335   __ addptr(rsp, rcx);
3336 
3337   // rsp should be pointing at the return address to the caller (3)
3338 
3339   // Pick up the initial fp we should save
3340   // restore rbp before stack bang because if stack overflow is thrown it needs to be pushed (and preserved)
3341   __ movptr(rbp, Address(rdi, Deoptimization::UnrollBlock::initial_info_offset_in_bytes()));
3342 
3343 #ifdef ASSERT
3344   // Compilers generate code that bang the stack by as much as the
3345   // interpreter would need. So this stack banging should never
3346   // trigger a fault. Verify that it does not on non product builds.
3347   if (UseStackBanging) {
3348     __ movl(rbx, Address(rdi ,Deoptimization::UnrollBlock::total_frame_sizes_offset_in_bytes()));
3349     __ bang_stack_size(rbx, rcx);
3350   }
3351 #endif
3352 
3353   // Load address of array of frame pcs into rcx (address*)
3354   __ movptr(rcx, Address(rdi, Deoptimization::UnrollBlock::frame_pcs_offset_in_bytes()));
3355 
3356   // Trash the return pc
3357   __ addptr(rsp, wordSize);
3358 
3359   // Load address of array of frame sizes into rsi (intptr_t*)
3360   __ movptr(rsi, Address(rdi, Deoptimization::UnrollBlock:: frame_sizes_offset_in_bytes()));
3361 
3362   // Counter
3363   __ movl(rdx, Address(rdi, Deoptimization::UnrollBlock:: number_of_frames_offset_in_bytes())); // (int)
3364 
3365   // Now adjust the caller's stack to make up for the extra locals but
3366   // record the original sp so that we can save it in the skeletal
3367   // interpreter frame and the stack walking of interpreter_sender
3368   // will get the unextended sp value and not the "real" sp value.
3369 
3370   const Register sender_sp = r8;
3371 
3372   __ mov(sender_sp, rsp);
3373   __ movl(rbx, Address(rdi, Deoptimization::UnrollBlock:: caller_adjustment_offset_in_bytes())); // (int)
3374   __ subptr(rsp, rbx);
3375 
3376   // Push interpreter frames in a loop
3377   Label loop;
3378   __ bind(loop);
3379   __ movptr(rbx, Address(rsi, 0)); // Load frame size
3380   __ subptr(rbx, 2 * wordSize);    // We'll push pc and rbp by hand
3381   __ pushptr(Address(rcx, 0));     // Save return address
3382   __ enter();                      // Save old & set new rbp
3383   __ subptr(rsp, rbx);             // Prolog
3384   __ movptr(Address(rbp, frame::interpreter_frame_sender_sp_offset * wordSize),
3385             sender_sp);            // Make it walkable
3386   // This value is corrected by layout_activation_impl
3387   __ movptr(Address(rbp, frame::interpreter_frame_last_sp_offset * wordSize), (int32_t)NULL_WORD );
3388   __ mov(sender_sp, rsp);          // Pass sender_sp to next frame
3389   __ addptr(rsi, wordSize);        // Bump array pointer (sizes)
3390   __ addptr(rcx, wordSize);        // Bump array pointer (pcs)
3391   __ decrementl(rdx);              // Decrement counter
3392   __ jcc(Assembler::notZero, loop);
3393   __ pushptr(Address(rcx, 0));     // Save final return address
3394 
3395   // Re-push self-frame
3396   __ enter();                 // Save old & set new rbp
3397   __ subptr(rsp, (SimpleRuntimeFrame::framesize - 4) << LogBytesPerInt);
3398                               // Prolog
3399 
3400   // Use rbp because the frames look interpreted now
3401   // Save "the_pc" since it cannot easily be retrieved using the last_java_SP after we aligned SP.
3402   // Don't need the precise return PC here, just precise enough to point into this code blob.
3403   address the_pc = __ pc();
3404   __ set_last_Java_frame(noreg, rbp, the_pc);
3405 
3406   // Call C code.  Need thread but NOT official VM entry
3407   // crud.  We cannot block on this call, no GC can happen.  Call should
3408   // restore return values to their stack-slots with the new SP.
3409   // Thread is in rdi already.
3410   //
3411   // BasicType unpack_frames(JavaThread* thread, int exec_mode);
3412 
3413   __ andptr(rsp, -(StackAlignmentInBytes)); // Align SP as required by ABI
3414   __ mov(c_rarg0, r15_thread);
3415   __ movl(c_rarg1, Deoptimization::Unpack_uncommon_trap);
3416   __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, Deoptimization::unpack_frames)));
3417 
3418   // Set an oopmap for the call site
3419   // Use the same PC we used for the last java frame
3420   oop_maps->add_gc_map(the_pc - start, new OopMap(SimpleRuntimeFrame::framesize, 0));
3421 
3422   // Clear fp AND pc
3423   __ reset_last_Java_frame(true);
3424 
3425   // Pop self-frame.
3426   __ leave();                 // Epilog
3427 
3428   // Jump to interpreter
3429   __ ret(0);
3430 
3431   // Make sure all code is generated
3432   masm->flush();
3433 
3434   _uncommon_trap_blob =  UncommonTrapBlob::create(&buffer, oop_maps,
3435                                                  SimpleRuntimeFrame::framesize >> 1);
3436 }
3437 #endif // COMPILER2
3438 
3439 
3440 //------------------------------generate_handler_blob------
3441 //
3442 // Generate a special Compile2Runtime blob that saves all registers,
3443 // and setup oopmap.
3444 //
3445 SafepointBlob* SharedRuntime::generate_handler_blob(address call_ptr, int poll_type) {
3446   assert(StubRoutines::forward_exception_entry() != NULL,
3447          "must be generated before");
3448 
3449   ResourceMark rm;
3450   OopMapSet *oop_maps = new OopMapSet();
3451   OopMap* map;
3452 
3453   // Allocate space for the code.  Setup code generation tools.
3454   CodeBuffer buffer("handler_blob", 2048, 1024);
3455   MacroAssembler* masm = new MacroAssembler(&buffer);
3456 
3457   address start   = __ pc();
3458   address call_pc = NULL;
3459   int frame_size_in_words;
3460   bool cause_return = (poll_type == POLL_AT_RETURN);
3461   bool save_vectors = (poll_type == POLL_AT_VECTOR_LOOP);
3462 
3463   if (UseRTMLocking) {
3464     // Abort RTM transaction before calling runtime
3465     // because critical section will be large and will be
3466     // aborted anyway. Also nmethod could be deoptimized.
3467     __ xabort(0);
3468   }
3469 
3470   // Make room for return address (or push it again)
3471   if (!cause_return) {
3472     __ push(rbx);
3473   }
3474 
3475   // Save registers, fpu state, and flags
3476   map = RegisterSaver::save_live_registers(masm, 0, &frame_size_in_words, save_vectors);
3477 
3478   // The following is basically a call_VM.  However, we need the precise
3479   // address of the call in order to generate an oopmap. Hence, we do all the
3480   // work outselves.
3481 
3482   __ set_last_Java_frame(noreg, noreg, NULL);
3483 
3484   // The return address must always be correct so that frame constructor never
3485   // sees an invalid pc.
3486 
3487   if (!cause_return) {
3488     // Get the return pc saved by the signal handler and stash it in its appropriate place on the stack.
3489     // Additionally, rbx is a callee saved register and we can look at it later to determine
3490     // if someone changed the return address for us!
3491     __ movptr(rbx, Address(r15_thread, JavaThread::saved_exception_pc_offset()));
3492     __ movptr(Address(rbp, wordSize), rbx);
3493   }
3494 
3495   // Do the call
3496   __ mov(c_rarg0, r15_thread);
3497   __ call(RuntimeAddress(call_ptr));
3498 
3499   // Set an oopmap for the call site.  This oopmap will map all
3500   // oop-registers and debug-info registers as callee-saved.  This
3501   // will allow deoptimization at this safepoint to find all possible
3502   // debug-info recordings, as well as let GC find all oops.
3503 
3504   oop_maps->add_gc_map( __ pc() - start, map);
3505 
3506   Label noException;
3507 
3508   __ reset_last_Java_frame(false);
3509 
3510   __ cmpptr(Address(r15_thread, Thread::pending_exception_offset()), (int32_t)NULL_WORD);
3511   __ jcc(Assembler::equal, noException);
3512 
3513   // Exception pending
3514 
3515   RegisterSaver::restore_live_registers(masm, save_vectors);
3516 
3517   __ jump(RuntimeAddress(StubRoutines::forward_exception_entry()));
3518 
3519   // No exception case
3520   __ bind(noException);
3521 
3522   Label no_adjust;
3523 #ifdef ASSERT
3524   Label bail;
3525 #endif
3526   if (SafepointMechanism::uses_thread_local_poll() && !cause_return) {
3527     Label no_prefix, not_special;
3528 
3529     // If our stashed return pc was modified by the runtime we avoid touching it
3530     __ cmpptr(rbx, Address(rbp, wordSize));
3531     __ jccb(Assembler::notEqual, no_adjust);
3532 
3533     // Skip over the poll instruction.
3534     // See NativeInstruction::is_safepoint_poll()
3535     // Possible encodings:
3536     //      85 00       test   %eax,(%rax)
3537     //      85 01       test   %eax,(%rcx)
3538     //      85 02       test   %eax,(%rdx)
3539     //      85 03       test   %eax,(%rbx)
3540     //      85 06       test   %eax,(%rsi)
3541     //      85 07       test   %eax,(%rdi)
3542     //
3543     //   41 85 00       test   %eax,(%r8)
3544     //   41 85 01       test   %eax,(%r9)
3545     //   41 85 02       test   %eax,(%r10)
3546     //   41 85 03       test   %eax,(%r11)
3547     //   41 85 06       test   %eax,(%r14)
3548     //   41 85 07       test   %eax,(%r15)
3549     //
3550     //      85 04 24    test   %eax,(%rsp)
3551     //   41 85 04 24    test   %eax,(%r12)
3552     //      85 45 00    test   %eax,0x0(%rbp)
3553     //   41 85 45 00    test   %eax,0x0(%r13)
3554 
3555     __ cmpb(Address(rbx, 0), NativeTstRegMem::instruction_rex_b_prefix);
3556     __ jcc(Assembler::notEqual, no_prefix);
3557     __ addptr(rbx, 1);
3558     __ bind(no_prefix);
3559 #ifdef ASSERT
3560     __ movptr(rax, rbx); // remember where 0x85 should be, for verification below
3561 #endif
3562     // r12/r13/rsp/rbp base encoding takes 3 bytes with the following register values:
3563     // r12/rsp 0x04
3564     // r13/rbp 0x05
3565     __ movzbq(rcx, Address(rbx, 1));
3566     __ andptr(rcx, 0x07); // looking for 0x04 .. 0x05
3567     __ subptr(rcx, 4);    // looking for 0x00 .. 0x01
3568     __ cmpptr(rcx, 1);
3569     __ jcc(Assembler::above, not_special);
3570     __ addptr(rbx, 1);
3571     __ bind(not_special);
3572 #ifdef ASSERT
3573     // Verify the correct encoding of the poll we're about to skip.
3574     __ cmpb(Address(rax, 0), NativeTstRegMem::instruction_code_memXregl);
3575     __ jcc(Assembler::notEqual, bail);
3576     // Mask out the modrm bits
3577     __ testb(Address(rax, 1), NativeTstRegMem::modrm_mask);
3578     // rax encodes to 0, so if the bits are nonzero it's incorrect
3579     __ jcc(Assembler::notZero, bail);
3580 #endif
3581     // Adjust return pc forward to step over the safepoint poll instruction
3582     __ addptr(rbx, 2);
3583     __ movptr(Address(rbp, wordSize), rbx);
3584   }
3585 
3586   __ bind(no_adjust);
3587   // Normal exit, restore registers and exit.
3588   RegisterSaver::restore_live_registers(masm, save_vectors);
3589   __ ret(0);
3590 
3591 #ifdef ASSERT
3592   __ bind(bail);
3593   __ stop("Attempting to adjust pc to skip safepoint poll but the return point is not what we expected");
3594 #endif
3595 
3596   // Make sure all code is generated
3597   masm->flush();
3598 
3599   // Fill-out other meta info
3600   return SafepointBlob::create(&buffer, oop_maps, frame_size_in_words);
3601 }
3602 
3603 //
3604 // generate_resolve_blob - call resolution (static/virtual/opt-virtual/ic-miss
3605 //
3606 // Generate a stub that calls into vm to find out the proper destination
3607 // of a java call. All the argument registers are live at this point
3608 // but since this is generic code we don't know what they are and the caller
3609 // must do any gc of the args.
3610 //
3611 RuntimeStub* SharedRuntime::generate_resolve_blob(address destination, const char* name) {
3612   assert (StubRoutines::forward_exception_entry() != NULL, "must be generated before");
3613 
3614   // allocate space for the code
3615   ResourceMark rm;
3616 
3617   CodeBuffer buffer(name, 1000, 512);
3618   MacroAssembler* masm                = new MacroAssembler(&buffer);
3619 
3620   int frame_size_in_words;
3621 
3622   OopMapSet *oop_maps = new OopMapSet();
3623   OopMap* map = NULL;
3624 
3625   int start = __ offset();
3626 
3627   map = RegisterSaver::save_live_registers(masm, 0, &frame_size_in_words);
3628 
3629   int frame_complete = __ offset();
3630 
3631   __ set_last_Java_frame(noreg, noreg, NULL);
3632 
3633   __ mov(c_rarg0, r15_thread);
3634 
3635   __ call(RuntimeAddress(destination));
3636 
3637 
3638   // Set an oopmap for the call site.
3639   // We need this not only for callee-saved registers, but also for volatile
3640   // registers that the compiler might be keeping live across a safepoint.
3641 
3642   oop_maps->add_gc_map( __ offset() - start, map);
3643 
3644   // rax contains the address we are going to jump to assuming no exception got installed
3645 
3646   // clear last_Java_sp
3647   __ reset_last_Java_frame(false);
3648   // check for pending exceptions
3649   Label pending;
3650   __ cmpptr(Address(r15_thread, Thread::pending_exception_offset()), (int32_t)NULL_WORD);
3651   __ jcc(Assembler::notEqual, pending);
3652 
3653   // get the returned Method*
3654   __ get_vm_result_2(rbx, r15_thread);
3655   __ movptr(Address(rsp, RegisterSaver::rbx_offset_in_bytes()), rbx);
3656 
3657   __ movptr(Address(rsp, RegisterSaver::rax_offset_in_bytes()), rax);
3658 
3659   RegisterSaver::restore_live_registers(masm);
3660 
3661   // We are back the the original state on entry and ready to go.
3662 
3663   __ jmp(rax);
3664 
3665   // Pending exception after the safepoint
3666 
3667   __ bind(pending);
3668 
3669   RegisterSaver::restore_live_registers(masm);
3670 
3671   // exception pending => remove activation and forward to exception handler
3672 
3673   __ movptr(Address(r15_thread, JavaThread::vm_result_offset()), (int)NULL_WORD);
3674 
3675   __ movptr(rax, Address(r15_thread, Thread::pending_exception_offset()));
3676   __ jump(RuntimeAddress(StubRoutines::forward_exception_entry()));
3677 
3678   // -------------
3679   // make sure all code is generated
3680   masm->flush();
3681 
3682   // return the  blob
3683   // frame_size_words or bytes??
3684   return RuntimeStub::new_runtime_stub(name, &buffer, frame_complete, frame_size_in_words, oop_maps, true);
3685 }
3686 
3687 
3688 //------------------------------Montgomery multiplication------------------------
3689 //
3690 
3691 #ifndef _WINDOWS
3692 
3693 #define ASM_SUBTRACT
3694 
3695 #ifdef ASM_SUBTRACT
3696 // Subtract 0:b from carry:a.  Return carry.
3697 static unsigned long
3698 sub(unsigned long a[], unsigned long b[], unsigned long carry, long len) {
3699   long i = 0, cnt = len;
3700   unsigned long tmp;
3701   asm volatile("clc; "
3702                "0: ; "
3703                "mov (%[b], %[i], 8), %[tmp]; "
3704                "sbb %[tmp], (%[a], %[i], 8); "
3705                "inc %[i]; dec %[cnt]; "
3706                "jne 0b; "
3707                "mov %[carry], %[tmp]; sbb $0, %[tmp]; "
3708                : [i]"+r"(i), [cnt]"+r"(cnt), [tmp]"=&r"(tmp)
3709                : [a]"r"(a), [b]"r"(b), [carry]"r"(carry)
3710                : "memory");
3711   return tmp;
3712 }
3713 #else // ASM_SUBTRACT
3714 typedef int __attribute__((mode(TI))) int128;
3715 
3716 // Subtract 0:b from carry:a.  Return carry.
3717 static unsigned long
3718 sub(unsigned long a[], unsigned long b[], unsigned long carry, int len) {
3719   int128 tmp = 0;
3720   int i;
3721   for (i = 0; i < len; i++) {
3722     tmp += a[i];
3723     tmp -= b[i];
3724     a[i] = tmp;
3725     tmp >>= 64;
3726     assert(-1 <= tmp && tmp <= 0, "invariant");
3727   }
3728   return tmp + carry;
3729 }
3730 #endif // ! ASM_SUBTRACT
3731 
3732 // Multiply (unsigned) Long A by Long B, accumulating the double-
3733 // length result into the accumulator formed of T0, T1, and T2.
3734 #define MACC(A, B, T0, T1, T2)                                  \
3735 do {                                                            \
3736   unsigned long hi, lo;                                         \
3737   __asm__ ("mul %5; add %%rax, %2; adc %%rdx, %3; adc $0, %4"   \
3738            : "=&d"(hi), "=a"(lo), "+r"(T0), "+r"(T1), "+g"(T2)  \
3739            : "r"(A), "a"(B) : "cc");                            \
3740  } while(0)
3741 
3742 // As above, but add twice the double-length result into the
3743 // accumulator.
3744 #define MACC2(A, B, T0, T1, T2)                                 \
3745 do {                                                            \
3746   unsigned long hi, lo;                                         \
3747   __asm__ ("mul %5; add %%rax, %2; adc %%rdx, %3; adc $0, %4; " \
3748            "add %%rax, %2; adc %%rdx, %3; adc $0, %4"           \
3749            : "=&d"(hi), "=a"(lo), "+r"(T0), "+r"(T1), "+g"(T2)  \
3750            : "r"(A), "a"(B) : "cc");                            \
3751  } while(0)
3752 
3753 // Fast Montgomery multiplication.  The derivation of the algorithm is
3754 // in  A Cryptographic Library for the Motorola DSP56000,
3755 // Dusse and Kaliski, Proc. EUROCRYPT 90, pp. 230-237.
3756 
3757 static void __attribute__((noinline))
3758 montgomery_multiply(unsigned long a[], unsigned long b[], unsigned long n[],
3759                     unsigned long m[], unsigned long inv, int len) {
3760   unsigned long t0 = 0, t1 = 0, t2 = 0; // Triple-precision accumulator
3761   int i;
3762 
3763   assert(inv * n[0] == -1UL, "broken inverse in Montgomery multiply");
3764 
3765   for (i = 0; i < len; i++) {
3766     int j;
3767     for (j = 0; j < i; j++) {
3768       MACC(a[j], b[i-j], t0, t1, t2);
3769       MACC(m[j], n[i-j], t0, t1, t2);
3770     }
3771     MACC(a[i], b[0], t0, t1, t2);
3772     m[i] = t0 * inv;
3773     MACC(m[i], n[0], t0, t1, t2);
3774 
3775     assert(t0 == 0, "broken Montgomery multiply");
3776 
3777     t0 = t1; t1 = t2; t2 = 0;
3778   }
3779 
3780   for (i = len; i < 2*len; i++) {
3781     int j;
3782     for (j = i-len+1; j < len; j++) {
3783       MACC(a[j], b[i-j], t0, t1, t2);
3784       MACC(m[j], n[i-j], t0, t1, t2);
3785     }
3786     m[i-len] = t0;
3787     t0 = t1; t1 = t2; t2 = 0;
3788   }
3789 
3790   while (t0)
3791     t0 = sub(m, n, t0, len);
3792 }
3793 
3794 // Fast Montgomery squaring.  This uses asymptotically 25% fewer
3795 // multiplies so it should be up to 25% faster than Montgomery
3796 // multiplication.  However, its loop control is more complex and it
3797 // may actually run slower on some machines.
3798 
3799 static void __attribute__((noinline))
3800 montgomery_square(unsigned long a[], unsigned long n[],
3801                   unsigned long m[], unsigned long inv, int len) {
3802   unsigned long t0 = 0, t1 = 0, t2 = 0; // Triple-precision accumulator
3803   int i;
3804 
3805   assert(inv * n[0] == -1UL, "broken inverse in Montgomery multiply");
3806 
3807   for (i = 0; i < len; i++) {
3808     int j;
3809     int end = (i+1)/2;
3810     for (j = 0; j < end; j++) {
3811       MACC2(a[j], a[i-j], t0, t1, t2);
3812       MACC(m[j], n[i-j], t0, t1, t2);
3813     }
3814     if ((i & 1) == 0) {
3815       MACC(a[j], a[j], t0, t1, t2);
3816     }
3817     for (; j < i; j++) {
3818       MACC(m[j], n[i-j], t0, t1, t2);
3819     }
3820     m[i] = t0 * inv;
3821     MACC(m[i], n[0], t0, t1, t2);
3822 
3823     assert(t0 == 0, "broken Montgomery square");
3824 
3825     t0 = t1; t1 = t2; t2 = 0;
3826   }
3827 
3828   for (i = len; i < 2*len; i++) {
3829     int start = i-len+1;
3830     int end = start + (len - start)/2;
3831     int j;
3832     for (j = start; j < end; j++) {
3833       MACC2(a[j], a[i-j], t0, t1, t2);
3834       MACC(m[j], n[i-j], t0, t1, t2);
3835     }
3836     if ((i & 1) == 0) {
3837       MACC(a[j], a[j], t0, t1, t2);
3838     }
3839     for (; j < len; j++) {
3840       MACC(m[j], n[i-j], t0, t1, t2);
3841     }
3842     m[i-len] = t0;
3843     t0 = t1; t1 = t2; t2 = 0;
3844   }
3845 
3846   while (t0)
3847     t0 = sub(m, n, t0, len);
3848 }
3849 
3850 // Swap words in a longword.
3851 static unsigned long swap(unsigned long x) {
3852   return (x << 32) | (x >> 32);
3853 }
3854 
3855 // Copy len longwords from s to d, word-swapping as we go.  The
3856 // destination array is reversed.
3857 static void reverse_words(unsigned long *s, unsigned long *d, int len) {
3858   d += len;
3859   while(len-- > 0) {
3860     d--;
3861     *d = swap(*s);
3862     s++;
3863   }
3864 }
3865 
3866 // The threshold at which squaring is advantageous was determined
3867 // experimentally on an i7-3930K (Ivy Bridge) CPU @ 3.5GHz.
3868 #define MONTGOMERY_SQUARING_THRESHOLD 64
3869 
3870 void SharedRuntime::montgomery_multiply(jint *a_ints, jint *b_ints, jint *n_ints,
3871                                         jint len, jlong inv,
3872                                         jint *m_ints) {
3873   assert(len % 2 == 0, "array length in montgomery_multiply must be even");
3874   int longwords = len/2;
3875 
3876   // Make very sure we don't use so much space that the stack might
3877   // overflow.  512 jints corresponds to an 16384-bit integer and
3878   // will use here a total of 8k bytes of stack space.
3879   int total_allocation = longwords * sizeof (unsigned long) * 4;
3880   guarantee(total_allocation <= 8192, "must be");
3881   unsigned long *scratch = (unsigned long *)alloca(total_allocation);
3882 
3883   // Local scratch arrays
3884   unsigned long
3885     *a = scratch + 0 * longwords,
3886     *b = scratch + 1 * longwords,
3887     *n = scratch + 2 * longwords,
3888     *m = scratch + 3 * longwords;
3889 
3890   reverse_words((unsigned long *)a_ints, a, longwords);
3891   reverse_words((unsigned long *)b_ints, b, longwords);
3892   reverse_words((unsigned long *)n_ints, n, longwords);
3893 
3894   ::montgomery_multiply(a, b, n, m, (unsigned long)inv, longwords);
3895 
3896   reverse_words(m, (unsigned long *)m_ints, longwords);
3897 }
3898 
3899 void SharedRuntime::montgomery_square(jint *a_ints, jint *n_ints,
3900                                       jint len, jlong inv,
3901                                       jint *m_ints) {
3902   assert(len % 2 == 0, "array length in montgomery_square must be even");
3903   int longwords = len/2;
3904 
3905   // Make very sure we don't use so much space that the stack might
3906   // overflow.  512 jints corresponds to an 16384-bit integer and
3907   // will use here a total of 6k bytes of stack space.
3908   int total_allocation = longwords * sizeof (unsigned long) * 3;
3909   guarantee(total_allocation <= 8192, "must be");
3910   unsigned long *scratch = (unsigned long *)alloca(total_allocation);
3911 
3912   // Local scratch arrays
3913   unsigned long
3914     *a = scratch + 0 * longwords,
3915     *n = scratch + 1 * longwords,
3916     *m = scratch + 2 * longwords;
3917 
3918   reverse_words((unsigned long *)a_ints, a, longwords);
3919   reverse_words((unsigned long *)n_ints, n, longwords);
3920 
3921   if (len >= MONTGOMERY_SQUARING_THRESHOLD) {
3922     ::montgomery_square(a, n, m, (unsigned long)inv, longwords);
3923   } else {
3924     ::montgomery_multiply(a, a, n, m, (unsigned long)inv, longwords);
3925   }
3926 
3927   reverse_words(m, (unsigned long *)m_ints, longwords);
3928 }
3929 
3930 #endif // WINDOWS
3931 
3932 #ifdef COMPILER2
3933 // This is here instead of runtime_x86_64.cpp because it uses SimpleRuntimeFrame
3934 //
3935 //------------------------------generate_exception_blob---------------------------
3936 // creates exception blob at the end
3937 // Using exception blob, this code is jumped from a compiled method.
3938 // (see emit_exception_handler in x86_64.ad file)
3939 //
3940 // Given an exception pc at a call we call into the runtime for the
3941 // handler in this method. This handler might merely restore state
3942 // (i.e. callee save registers) unwind the frame and jump to the
3943 // exception handler for the nmethod if there is no Java level handler
3944 // for the nmethod.
3945 //
3946 // This code is entered with a jmp.
3947 //
3948 // Arguments:
3949 //   rax: exception oop
3950 //   rdx: exception pc
3951 //
3952 // Results:
3953 //   rax: exception oop
3954 //   rdx: exception pc in caller or ???
3955 //   destination: exception handler of caller
3956 //
3957 // Note: the exception pc MUST be at a call (precise debug information)
3958 //       Registers rax, rdx, rcx, rsi, rdi, r8-r11 are not callee saved.
3959 //
3960 
3961 void OptoRuntime::generate_exception_blob() {
3962   assert(!OptoRuntime::is_callee_saved_register(RDX_num), "");
3963   assert(!OptoRuntime::is_callee_saved_register(RAX_num), "");
3964   assert(!OptoRuntime::is_callee_saved_register(RCX_num), "");
3965 
3966   assert(SimpleRuntimeFrame::framesize % 4 == 0, "sp not 16-byte aligned");
3967 
3968   // Allocate space for the code
3969   ResourceMark rm;
3970   // Setup code generation tools
3971   CodeBuffer buffer("exception_blob", 2048, 1024);
3972   MacroAssembler* masm = new MacroAssembler(&buffer);
3973 
3974 
3975   address start = __ pc();
3976 
3977   // Exception pc is 'return address' for stack walker
3978   __ push(rdx);
3979   __ subptr(rsp, SimpleRuntimeFrame::return_off << LogBytesPerInt); // Prolog
3980 
3981   // Save callee-saved registers.  See x86_64.ad.
3982 
3983   // rbp is an implicitly saved callee saved register (i.e., the calling
3984   // convention will save/restore it in the prolog/epilog). Other than that
3985   // there are no callee save registers now that adapter frames are gone.
3986 
3987   __ movptr(Address(rsp, SimpleRuntimeFrame::rbp_off << LogBytesPerInt), rbp);
3988 
3989   // Store exception in Thread object. We cannot pass any arguments to the
3990   // handle_exception call, since we do not want to make any assumption
3991   // about the size of the frame where the exception happened in.
3992   // c_rarg0 is either rdi (Linux) or rcx (Windows).
3993   __ movptr(Address(r15_thread, JavaThread::exception_oop_offset()),rax);
3994   __ movptr(Address(r15_thread, JavaThread::exception_pc_offset()), rdx);
3995 
3996   // This call does all the hard work.  It checks if an exception handler
3997   // exists in the method.
3998   // If so, it returns the handler address.
3999   // If not, it prepares for stack-unwinding, restoring the callee-save
4000   // registers of the frame being removed.
4001   //
4002   // address OptoRuntime::handle_exception_C(JavaThread* thread)
4003 
4004   // At a method handle call, the stack may not be properly aligned
4005   // when returning with an exception.
4006   address the_pc = __ pc();
4007   __ set_last_Java_frame(noreg, noreg, the_pc);
4008   __ mov(c_rarg0, r15_thread);
4009   __ andptr(rsp, -(StackAlignmentInBytes));    // Align stack
4010   __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, OptoRuntime::handle_exception_C)));
4011 
4012   // Set an oopmap for the call site.  This oopmap will only be used if we
4013   // are unwinding the stack.  Hence, all locations will be dead.
4014   // Callee-saved registers will be the same as the frame above (i.e.,
4015   // handle_exception_stub), since they were restored when we got the
4016   // exception.
4017 
4018   OopMapSet* oop_maps = new OopMapSet();
4019 
4020   oop_maps->add_gc_map(the_pc - start, new OopMap(SimpleRuntimeFrame::framesize, 0));
4021 
4022   __ reset_last_Java_frame(false);
4023 
4024   // Restore callee-saved registers
4025 
4026   // rbp is an implicitly saved callee-saved register (i.e., the calling
4027   // convention will save restore it in prolog/epilog) Other than that
4028   // there are no callee save registers now that adapter frames are gone.
4029 
4030   __ movptr(rbp, Address(rsp, SimpleRuntimeFrame::rbp_off << LogBytesPerInt));
4031 
4032   __ addptr(rsp, SimpleRuntimeFrame::return_off << LogBytesPerInt); // Epilog
4033   __ pop(rdx);                  // No need for exception pc anymore
4034 
4035   // rax: exception handler
4036 
4037   // We have a handler in rax (could be deopt blob).
4038   __ mov(r8, rax);
4039 
4040   // Get the exception oop
4041   __ movptr(rax, Address(r15_thread, JavaThread::exception_oop_offset()));
4042   // Get the exception pc in case we are deoptimized
4043   __ movptr(rdx, Address(r15_thread, JavaThread::exception_pc_offset()));
4044 #ifdef ASSERT
4045   __ movptr(Address(r15_thread, JavaThread::exception_handler_pc_offset()), (int)NULL_WORD);
4046   __ movptr(Address(r15_thread, JavaThread::exception_pc_offset()), (int)NULL_WORD);
4047 #endif
4048   // Clear the exception oop so GC no longer processes it as a root.
4049   __ movptr(Address(r15_thread, JavaThread::exception_oop_offset()), (int)NULL_WORD);
4050 
4051   // rax: exception oop
4052   // r8:  exception handler
4053   // rdx: exception pc
4054   // Jump to handler
4055 
4056   __ jmp(r8);
4057 
4058   // Make sure all code is generated
4059   masm->flush();
4060 
4061   // Set exception blob
4062   _exception_blob =  ExceptionBlob::create(&buffer, oop_maps, SimpleRuntimeFrame::framesize >> 1);
4063 }
4064 #endif // COMPILER2