1 /*
   2  * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2016 SAP SE. All rights reserved.
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This code is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 only, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This code is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * version 2 for more details (a copy is included in the LICENSE file that
  14  * accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License version
  17  * 2 along with this work; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  21  * or visit www.oracle.com if you need additional information or have any
  22  * questions.
  23  *
  24  */
  25 
  26 // Major contributions by AHa, AS, JL, ML.
  27 
  28 #include "precompiled.hpp"
  29 #include "asm/macroAssembler.inline.hpp"
  30 #include "interp_masm_s390.hpp"
  31 #include "interpreter/interpreter.hpp"
  32 #include "interpreter/interpreterRuntime.hpp"
  33 #include "oops/arrayOop.hpp"
  34 #include "oops/markOop.hpp"
  35 #include "prims/jvmtiExport.hpp"
  36 #include "prims/jvmtiThreadState.hpp"
  37 #include "runtime/basicLock.hpp"
  38 #include "runtime/biasedLocking.hpp"
  39 #include "runtime/sharedRuntime.hpp"
  40 #include "runtime/thread.inline.hpp"
  41 
  42 // Implementation of InterpreterMacroAssembler.
  43 // This file specializes the assember with interpreter-specific macros.
  44 
  45 #ifdef PRODUCT
  46 #define BLOCK_COMMENT(str)
  47 #define BIND(label)        bind(label);
  48 #else
  49 #define BLOCK_COMMENT(str) block_comment(str)
  50 #define BIND(label)        bind(label); BLOCK_COMMENT(#label ":")
  51 #endif
  52 
  53 void InterpreterMacroAssembler::jump_to_entry(address entry, Register Rscratch) {
  54   assert(entry != NULL, "Entry must have been generated by now");
  55   assert(Rscratch != Z_R0, "Can't use R0 for addressing");
  56   branch_optimized(Assembler::bcondAlways, entry);
  57 }
  58 
  59 void InterpreterMacroAssembler::empty_expression_stack(void) {
  60   get_monitors(Z_R1_scratch);
  61   add2reg(Z_esp, -Interpreter::stackElementSize, Z_R1_scratch);
  62 }
  63 
  64 // Dispatch code executed in the prolog of a bytecode which does not do it's
  65 // own dispatch.
  66 void InterpreterMacroAssembler::dispatch_prolog(TosState state, int bcp_incr) {
  67   // On z/Architecture we are short on registers, therefore we do not preload the
  68   // dispatch address of the next bytecode.
  69 }
  70 
  71 // Dispatch code executed in the epilog of a bytecode which does not do it's
  72 // own dispatch.
  73 void InterpreterMacroAssembler::dispatch_epilog(TosState state, int step) {
  74   dispatch_next(state, step);
  75 }
  76 
  77 void InterpreterMacroAssembler::dispatch_next(TosState state, int bcp_incr) {
  78   z_llgc(Z_bytecode, bcp_incr, Z_R0, Z_bcp);  // Load next bytecode.
  79   add2reg(Z_bcp, bcp_incr);                   // Advance bcp. Add2reg produces optimal code.
  80   dispatch_base(state, Interpreter::dispatch_table(state));
  81 }
  82 
  83 // Common code to dispatch and dispatch_only.
  84 // Dispatch value in Lbyte_code and increment Lbcp.
  85 
  86 void InterpreterMacroAssembler::dispatch_base(TosState state, address* table) {
  87   verify_FPU(1, state);
  88 
  89 #ifdef ASSERT
  90   address reentry = NULL;
  91   { Label OK;
  92     // Check if the frame pointer in Z_fp is correct.
  93     z_cg(Z_fp, 0, Z_SP);
  94     z_bre(OK);
  95     reentry = stop_chain_static(reentry, "invalid frame pointer Z_fp: " FILE_AND_LINE);
  96     bind(OK);
  97   }
  98   { Label OK;
  99     // check if the locals pointer in Z_locals is correct
 100     z_cg(Z_locals, _z_ijava_state_neg(locals), Z_fp);
 101     z_bre(OK);
 102     reentry = stop_chain_static(reentry, "invalid locals pointer Z_locals: " FILE_AND_LINE);
 103     bind(OK);
 104   }
 105 #endif
 106 
 107   // TODO: Maybe implement +VerifyActivationFrameSize here.
 108   // verify_thread(); // Too slow. We will just verify on method entry & exit.
 109   verify_oop(Z_tos, state);
 110 #ifdef FAST_DISPATCH
 111   if (table == Interpreter::dispatch_table(state)) {
 112     // Use IdispatchTables.
 113     add(Lbyte_code, Interpreter::distance_from_dispatch_table(state), Lbyte_code);
 114                                                         // Add offset to correct dispatch table.
 115     sll(Lbyte_code, LogBytesPerWord, Lbyte_code);       // Multiply by wordSize.
 116     ld_ptr(IdispatchTables, Lbyte_code, G3_scratch);    // Get entry addr.
 117   } else
 118 #endif
 119   {
 120     // Dispatch table to use.
 121     load_absolute_address(Z_tmp_1, (address) table);  // Z_tmp_1 = table;
 122 
 123     // 0 <= Z_bytecode < 256 => Use a 32 bit shift, because it is shorter than sllg.
 124     // Z_bytecode must have been loaded zero-extended for this approach to be correct.
 125     z_sll(Z_bytecode, LogBytesPerWord, Z_R0);   // Multiply by wordSize.
 126     z_lg(Z_tmp_1, 0, Z_bytecode, Z_tmp_1);      // Get entry addr.
 127   }
 128   z_br(Z_tmp_1);
 129 }
 130 
 131 void InterpreterMacroAssembler::dispatch_only(TosState state) {
 132   dispatch_base(state, Interpreter::dispatch_table(state));
 133 }
 134 
 135 void InterpreterMacroAssembler::dispatch_only_normal(TosState state) {
 136   dispatch_base(state, Interpreter::normal_table(state));
 137 }
 138 
 139 void InterpreterMacroAssembler::dispatch_via(TosState state, address *table) {
 140   // Load current bytecode.
 141   z_llgc(Z_bytecode, Address(Z_bcp, (intptr_t)0));
 142   dispatch_base(state, table);
 143 }
 144 
 145 // The following call_VM*_base() methods overload and mask the respective
 146 // declarations/definitions in class MacroAssembler. They are meant as a "detour"
 147 // to perform additional, template interpreter specific tasks before actually
 148 // calling their MacroAssembler counterparts.
 149 
 150 void InterpreterMacroAssembler::call_VM_leaf_base(address entry_point) {
 151   bool allow_relocation = true; // Fenerally valid variant. Assume code is relocated.
 152   // interpreter specific
 153   // Note: No need to save/restore bcp (Z_R13) pointer since these are callee
 154   // saved registers and no blocking/ GC can happen in leaf calls.
 155 
 156   // super call
 157   MacroAssembler::call_VM_leaf_base(entry_point, allow_relocation);
 158 }
 159 
 160 void InterpreterMacroAssembler::call_VM_leaf_base(address entry_point, bool allow_relocation) {
 161   // interpreter specific
 162   // Note: No need to save/restore bcp (Z_R13) pointer since these are callee
 163   // saved registers and no blocking/ GC can happen in leaf calls.
 164 
 165   // super call
 166   MacroAssembler::call_VM_leaf_base(entry_point, allow_relocation);
 167 }
 168 
 169 void InterpreterMacroAssembler::call_VM_base(Register oop_result, Register last_java_sp,
 170                                              address entry_point, bool check_exceptions) {
 171   bool allow_relocation = true; // Fenerally valid variant. Assume code is relocated.
 172   // interpreter specific
 173 
 174   save_bcp();
 175   save_esp();
 176   // super call
 177   MacroAssembler::call_VM_base(oop_result, last_java_sp,
 178                                entry_point, allow_relocation, check_exceptions);
 179   restore_bcp();
 180 }
 181 
 182 void InterpreterMacroAssembler::call_VM_base(Register oop_result, Register last_java_sp,
 183                                              address entry_point, bool allow_relocation,
 184                                              bool check_exceptions) {
 185   // interpreter specific
 186 
 187   save_bcp();
 188   save_esp();
 189   // super call
 190   MacroAssembler::call_VM_base(oop_result, last_java_sp,
 191                                entry_point, allow_relocation, check_exceptions);
 192   restore_bcp();
 193 }
 194 
 195 void InterpreterMacroAssembler::check_and_handle_popframe(Register scratch_reg) {
 196   if (JvmtiExport::can_pop_frame()) {
 197     BLOCK_COMMENT("check_and_handle_popframe {");
 198     Label L;
 199     // Initiate popframe handling only if it is not already being
 200     // processed. If the flag has the popframe_processing bit set, it
 201     // means that this code is called *during* popframe handling - we
 202     // don't want to reenter.
 203     // TODO: Check if all four state combinations could be visible.
 204     // If (processing and !pending) is an invisible/impossible state,
 205     // there is optimization potential by testing both bits at once.
 206     // Then, All_Zeroes and All_Ones means skip, Mixed means doit.
 207     testbit(Address(Z_thread, JavaThread::popframe_condition_offset()),
 208             exact_log2(JavaThread::popframe_pending_bit));
 209     z_bfalse(L);
 210     testbit(Address(Z_thread, JavaThread::popframe_condition_offset()),
 211             exact_log2(JavaThread::popframe_processing_bit));
 212     z_btrue(L);
 213 
 214     // Call Interpreter::remove_activation_preserving_args_entry() to get the
 215     // address of the same-named entrypoint in the generated interpreter code.
 216     call_VM_leaf(CAST_FROM_FN_PTR(address, Interpreter::remove_activation_preserving_args_entry));
 217     // The above call should (as its only effect) return the contents of the field
 218     // _remove_activation_preserving_args_entry in Z_RET.
 219     // We just jump there to have the work done.
 220     z_br(Z_RET);
 221     // There is no way for control to fall thru here.
 222 
 223     bind(L);
 224     BLOCK_COMMENT("} check_and_handle_popframe");
 225   }
 226 }
 227 
 228 
 229 void InterpreterMacroAssembler::load_earlyret_value(TosState state) {
 230   Register RjvmtiState = Z_R1_scratch;
 231   int      tos_off     = in_bytes(JvmtiThreadState::earlyret_tos_offset());
 232   int      oop_off     = in_bytes(JvmtiThreadState::earlyret_oop_offset());
 233   int      val_off     = in_bytes(JvmtiThreadState::earlyret_value_offset());
 234   int      state_off   = in_bytes(JavaThread::jvmti_thread_state_offset());
 235 
 236   z_lg(RjvmtiState, state_off, Z_thread);
 237 
 238   switch (state) {
 239     case atos: z_lg(Z_tos, oop_off, RjvmtiState);
 240       store_const(Address(RjvmtiState, oop_off), 0L, 8, 8, Z_R0_scratch);
 241                                                     break;
 242     case ltos: z_lg(Z_tos, val_off, RjvmtiState);   break;
 243     case btos: // fall through
 244     case ztos: // fall through
 245     case ctos: // fall through
 246     case stos: // fall through
 247     case itos: z_llgf(Z_tos, val_off, RjvmtiState); break;
 248     case ftos: z_le(Z_ftos, val_off, RjvmtiState);  break;
 249     case dtos: z_ld(Z_ftos, val_off, RjvmtiState);  break;
 250     case vtos:   /* nothing to do */                break;
 251     default  : ShouldNotReachHere();
 252   }
 253 
 254   // Clean up tos value in the jvmti thread state.
 255   store_const(Address(RjvmtiState, val_off),   0L, 8, 8, Z_R0_scratch);
 256   // Set tos state field to illegal value.
 257   store_const(Address(RjvmtiState, tos_off), ilgl, 4, 1, Z_R0_scratch);
 258 }
 259 
 260 void InterpreterMacroAssembler::check_and_handle_earlyret(Register scratch_reg) {
 261   if (JvmtiExport::can_force_early_return()) {
 262     BLOCK_COMMENT("check_and_handle_earlyret {");
 263     Label L;
 264     // arg regs are save, because we are just behind the call in call_VM_base
 265     Register jvmti_thread_state = Z_ARG2;
 266     Register tmp                = Z_ARG3;
 267     load_and_test_long(jvmti_thread_state, Address(Z_thread, JavaThread::jvmti_thread_state_offset()));
 268     z_bre(L); // if (thread->jvmti_thread_state() == NULL) exit;
 269 
 270     // Initiate earlyret handling only if it is not already being processed.
 271     // If the flag has the earlyret_processing bit set, it means that this code
 272     // is called *during* earlyret handling - we don't want to reenter.
 273 
 274     assert((JvmtiThreadState::earlyret_pending != 0) && (JvmtiThreadState::earlyret_inactive == 0),
 275           "must fix this check, when changing the values of the earlyret enum");
 276     assert(JvmtiThreadState::earlyret_pending == 1, "must fix this check, when changing the values of the earlyret enum");
 277 
 278     load_and_test_int(tmp, Address(jvmti_thread_state, JvmtiThreadState::earlyret_state_offset()));
 279     z_brz(L); // if (thread->jvmti_thread_state()->_earlyret_state != JvmtiThreadState::earlyret_pending) exit;
 280 
 281     // Call Interpreter::remove_activation_early_entry() to get the address of the
 282     // same-named entrypoint in the generated interpreter code.
 283     assert(sizeof(TosState) == 4, "unexpected size");
 284     z_l(Z_ARG1, Address(jvmti_thread_state, JvmtiThreadState::earlyret_tos_offset()));
 285     call_VM_leaf(CAST_FROM_FN_PTR(address, Interpreter::remove_activation_early_entry), Z_ARG1);
 286     // The above call should (as its only effect) return the contents of the field
 287     // _remove_activation_preserving_args_entry in Z_RET.
 288     // We just jump there to have the work done.
 289     z_br(Z_RET);
 290     // There is no way for control to fall thru here.
 291 
 292     bind(L);
 293     BLOCK_COMMENT("} check_and_handle_earlyret");
 294   }
 295 }
 296 
 297 void InterpreterMacroAssembler::super_call_VM_leaf(address entry_point, Register arg_1, Register arg_2) {
 298   lgr_if_needed(Z_ARG1, arg_1);
 299   assert(arg_2 != Z_ARG1, "smashed argument");
 300   lgr_if_needed(Z_ARG2, arg_2);
 301   MacroAssembler::call_VM_leaf_base(entry_point, true);
 302 }
 303 
 304 void InterpreterMacroAssembler::get_cache_index_at_bcp(Register index, int bcp_offset, size_t index_size) {
 305   Address param(Z_bcp, bcp_offset);
 306 
 307   BLOCK_COMMENT("get_cache_index_at_bcp {");
 308   assert(bcp_offset > 0, "bcp is still pointing to start of bytecode");
 309   if (index_size == sizeof(u2)) {
 310     load_sized_value(index, param, 2, false /*signed*/);
 311   } else if (index_size == sizeof(u4)) {
 312 
 313     load_sized_value(index, param, 4, false);
 314 
 315     // Check if the secondary index definition is still ~x, otherwise
 316     // we have to change the following assembler code to calculate the
 317     // plain index.
 318     assert(ConstantPool::decode_invokedynamic_index(~123) == 123, "else change next line");
 319     not_(index);  // Convert to plain index.
 320   } else if (index_size == sizeof(u1)) {
 321     z_llgc(index, param);
 322   } else {
 323     ShouldNotReachHere();
 324   }
 325   BLOCK_COMMENT("}");
 326 }
 327 
 328 
 329 void InterpreterMacroAssembler::get_cache_and_index_at_bcp(Register cache, Register cpe_offset,
 330                                                            int bcp_offset, size_t index_size) {
 331   BLOCK_COMMENT("get_cache_and_index_at_bcp {");
 332   assert_different_registers(cache, cpe_offset);
 333   get_cache_index_at_bcp(cpe_offset, bcp_offset, index_size);
 334   z_lg(cache, Address(Z_fp, _z_ijava_state_neg(cpoolCache)));
 335   // Convert from field index to ConstantPoolCache offset in bytes.
 336   z_sllg(cpe_offset, cpe_offset, exact_log2(in_words(ConstantPoolCacheEntry::size()) * BytesPerWord));
 337   BLOCK_COMMENT("}");
 338 }
 339 
 340 // Kills Z_R0_scratch.
 341 void InterpreterMacroAssembler::get_cache_and_index_and_bytecode_at_bcp(Register cache,
 342                                                                         Register cpe_offset,
 343                                                                         Register bytecode,
 344                                                                         int byte_no,
 345                                                                         int bcp_offset,
 346                                                                         size_t index_size) {
 347   BLOCK_COMMENT("get_cache_and_index_and_bytecode_at_bcp {");
 348   get_cache_and_index_at_bcp(cache, cpe_offset, bcp_offset, index_size);
 349 
 350   // We want to load (from CP cache) the bytecode that corresponds to the passed-in byte_no.
 351   // It is located at (cache + cpe_offset + base_offset + indices_offset + (8-1) (last byte in DW) - (byte_no+1).
 352   // Instead of loading, shifting and masking a DW, we just load that one byte of interest with z_llgc (unsigned).
 353   const int base_ix_off = in_bytes(ConstantPoolCache::base_offset() + ConstantPoolCacheEntry::indices_offset());
 354   const int off_in_DW   = (8-1) - (1+byte_no);
 355   assert(ConstantPoolCacheEntry::bytecode_1_mask == ConstantPoolCacheEntry::bytecode_2_mask, "common mask");
 356   assert(ConstantPoolCacheEntry::bytecode_1_mask == 0xff, "");
 357   load_sized_value(bytecode, Address(cache, cpe_offset, base_ix_off+off_in_DW), 1, false /*signed*/);
 358 
 359   BLOCK_COMMENT("}");
 360 }
 361 
 362 // Load object from cpool->resolved_references(index).
 363 void InterpreterMacroAssembler::load_resolved_reference_at_index(Register result, Register index) {
 364   assert_different_registers(result, index);
 365   get_constant_pool(result);
 366 
 367   // Convert
 368   //  - from field index to resolved_references() index and
 369   //  - from word index to byte offset.
 370   // Since this is a java object, it is potentially compressed.
 371   Register tmp = index;  // reuse
 372   z_sllg(index, index, LogBytesPerHeapOop); // Offset into resolved references array.
 373   // Load pointer for resolved_references[] objArray.
 374   z_lg(result, ConstantPool::resolved_references_offset_in_bytes(), result);
 375   // JNIHandles::resolve(result)
 376   z_lg(result, 0, result); // Load resolved references array itself.
 377 #ifdef ASSERT
 378   NearLabel index_ok;
 379   z_lgf(Z_R0, Address(result, arrayOopDesc::length_offset_in_bytes()));
 380   z_sllg(Z_R0, Z_R0, LogBytesPerHeapOop);
 381   compare64_and_branch(tmp, Z_R0, Assembler::bcondLow, index_ok);
 382   stop("resolved reference index out of bounds", 0x09256);
 383   bind(index_ok);
 384 #endif
 385   z_agr(result, index);    // Address of indexed array element.
 386   load_heap_oop(result, arrayOopDesc::base_offset_in_bytes(T_OBJECT), result);
 387 }
 388 
 389 void InterpreterMacroAssembler::get_cache_entry_pointer_at_bcp(Register cache,
 390                                                                Register tmp,
 391                                                                int bcp_offset,
 392                                                                size_t index_size) {
 393   BLOCK_COMMENT("get_cache_entry_pointer_at_bcp {");
 394     get_cache_and_index_at_bcp(cache, tmp, bcp_offset, index_size);
 395     add2reg_with_index(cache, in_bytes(ConstantPoolCache::base_offset()), tmp, cache);
 396   BLOCK_COMMENT("}");
 397 }
 398 
 399 // Generate a subtype check: branch to ok_is_subtype if sub_klass is
 400 // a subtype of super_klass. Blows registers Rsuper_klass, Rsub_klass, tmp1, tmp2.
 401 void InterpreterMacroAssembler::gen_subtype_check(Register Rsub_klass,
 402                                                   Register Rsuper_klass,
 403                                                   Register Rtmp1,
 404                                                   Register Rtmp2,
 405                                                   Label &ok_is_subtype) {
 406   // Profile the not-null value's klass.
 407   profile_typecheck(Rtmp1, Rsub_klass, Rtmp2);
 408 
 409   // Do the check.
 410   check_klass_subtype(Rsub_klass, Rsuper_klass, Rtmp1, Rtmp2, ok_is_subtype);
 411 
 412   // Profile the failure of the check.
 413   profile_typecheck_failed(Rtmp1, Rtmp2);
 414 }
 415 
 416 // Pop topmost element from stack. It just disappears.
 417 // Useful if consumed previously by access via stackTop().
 418 void InterpreterMacroAssembler::popx(int len) {
 419   add2reg(Z_esp, len*Interpreter::stackElementSize);
 420   debug_only(verify_esp(Z_esp, Z_R1_scratch));
 421 }
 422 
 423 // Get Address object of stack top. No checks. No pop.
 424 // Purpose: - Provide address of stack operand to exploit reg-mem operations.
 425 //          - Avoid RISC-like mem2reg - reg-reg-op sequence.
 426 Address InterpreterMacroAssembler::stackTop() {
 427   return Address(Z_esp, Interpreter::expr_offset_in_bytes(0));
 428 }
 429 
 430 void InterpreterMacroAssembler::pop_i(Register r) {
 431   z_l(r, Interpreter::expr_offset_in_bytes(0), Z_esp);
 432   add2reg(Z_esp, Interpreter::stackElementSize);
 433   assert_different_registers(r, Z_R1_scratch);
 434   debug_only(verify_esp(Z_esp, Z_R1_scratch));
 435 }
 436 
 437 void InterpreterMacroAssembler::pop_ptr(Register r) {
 438   z_lg(r, Interpreter::expr_offset_in_bytes(0), Z_esp);
 439   add2reg(Z_esp, Interpreter::stackElementSize);
 440   assert_different_registers(r, Z_R1_scratch);
 441   debug_only(verify_esp(Z_esp, Z_R1_scratch));
 442 }
 443 
 444 void InterpreterMacroAssembler::pop_l(Register r) {
 445   z_lg(r, Interpreter::expr_offset_in_bytes(0), Z_esp);
 446   add2reg(Z_esp, 2*Interpreter::stackElementSize);
 447   assert_different_registers(r, Z_R1_scratch);
 448   debug_only(verify_esp(Z_esp, Z_R1_scratch));
 449 }
 450 
 451 void InterpreterMacroAssembler::pop_f(FloatRegister f) {
 452   mem2freg_opt(f, Address(Z_esp, Interpreter::expr_offset_in_bytes(0)), false);
 453   add2reg(Z_esp, Interpreter::stackElementSize);
 454   debug_only(verify_esp(Z_esp, Z_R1_scratch));
 455 }
 456 
 457 void InterpreterMacroAssembler::pop_d(FloatRegister f) {
 458   mem2freg_opt(f, Address(Z_esp, Interpreter::expr_offset_in_bytes(0)), true);
 459   add2reg(Z_esp, 2*Interpreter::stackElementSize);
 460   debug_only(verify_esp(Z_esp, Z_R1_scratch));
 461 }
 462 
 463 void InterpreterMacroAssembler::push_i(Register r) {
 464   assert_different_registers(r, Z_R1_scratch);
 465   debug_only(verify_esp(Z_esp, Z_R1_scratch));
 466   z_st(r, Address(Z_esp));
 467   add2reg(Z_esp, -Interpreter::stackElementSize);
 468 }
 469 
 470 void InterpreterMacroAssembler::push_ptr(Register r) {
 471   z_stg(r, Address(Z_esp));
 472   add2reg(Z_esp, -Interpreter::stackElementSize);
 473 }
 474 
 475 void InterpreterMacroAssembler::push_l(Register r) {
 476   assert_different_registers(r, Z_R1_scratch);
 477   debug_only(verify_esp(Z_esp, Z_R1_scratch));
 478   int offset = -Interpreter::stackElementSize;
 479   z_stg(r, Address(Z_esp, offset));
 480   clear_mem(Address(Z_esp), Interpreter::stackElementSize);
 481   add2reg(Z_esp, 2 * offset);
 482 }
 483 
 484 void InterpreterMacroAssembler::push_f(FloatRegister f) {
 485   debug_only(verify_esp(Z_esp, Z_R1_scratch));
 486   freg2mem_opt(f, Address(Z_esp), false);
 487   add2reg(Z_esp, -Interpreter::stackElementSize);
 488 }
 489 
 490 void InterpreterMacroAssembler::push_d(FloatRegister d) {
 491   debug_only(verify_esp(Z_esp, Z_R1_scratch));
 492   int offset = -Interpreter::stackElementSize;
 493   freg2mem_opt(d, Address(Z_esp, offset));
 494   add2reg(Z_esp, 2 * offset);
 495 }
 496 
 497 void InterpreterMacroAssembler::push(TosState state) {
 498   verify_oop(Z_tos, state);
 499   switch (state) {
 500     case atos: push_ptr();           break;
 501     case btos: push_i();             break;
 502     case ztos:
 503     case ctos:
 504     case stos: push_i();             break;
 505     case itos: push_i();             break;
 506     case ltos: push_l();             break;
 507     case ftos: push_f();             break;
 508     case dtos: push_d();             break;
 509     case vtos: /* nothing to do */   break;
 510     default  : ShouldNotReachHere();
 511   }
 512 }
 513 
 514 void InterpreterMacroAssembler::pop(TosState state) {
 515   switch (state) {
 516     case atos: pop_ptr(Z_tos);       break;
 517     case btos: pop_i(Z_tos);         break;
 518     case ztos:
 519     case ctos:
 520     case stos: pop_i(Z_tos);         break;
 521     case itos: pop_i(Z_tos);         break;
 522     case ltos: pop_l(Z_tos);         break;
 523     case ftos: pop_f(Z_ftos);        break;
 524     case dtos: pop_d(Z_ftos);        break;
 525     case vtos: /* nothing to do */   break;
 526     default  : ShouldNotReachHere();
 527   }
 528   verify_oop(Z_tos, state);
 529 }
 530 
 531 // Helpers for swap and dup.
 532 void InterpreterMacroAssembler::load_ptr(int n, Register val) {
 533   z_lg(val, Address(Z_esp, Interpreter::expr_offset_in_bytes(n)));
 534 }
 535 
 536 void InterpreterMacroAssembler::store_ptr(int n, Register val) {
 537   z_stg(val, Address(Z_esp, Interpreter::expr_offset_in_bytes(n)));
 538 }
 539 
 540 void InterpreterMacroAssembler::prepare_to_jump_from_interpreted(Register method) {
 541   // Satisfy interpreter calling convention (see generate_normal_entry()).
 542   z_lgr(Z_R10, Z_SP); // Set sender sp (aka initial caller sp, aka unextended sp).
 543   // Record top_frame_sp, because the callee might modify it, if it's compiled.
 544   z_stg(Z_SP, _z_ijava_state_neg(top_frame_sp), Z_fp);
 545   save_bcp();
 546   save_esp();
 547   z_lgr(Z_method, method); // Set Z_method (kills Z_fp!).
 548 }
 549 
 550 // Jump to from_interpreted entry of a call unless single stepping is possible
 551 // in this thread in which case we must call the i2i entry.
 552 void InterpreterMacroAssembler::jump_from_interpreted(Register method, Register temp) {
 553   assert_different_registers(method, Z_R10 /*used for initial_caller_sp*/, temp);
 554   prepare_to_jump_from_interpreted(method);
 555 
 556   if (JvmtiExport::can_post_interpreter_events()) {
 557     // JVMTI events, such as single-stepping, are implemented partly by avoiding running
 558     // compiled code in threads for which the event is enabled. Check here for
 559     // interp_only_mode if these events CAN be enabled.
 560     z_lg(Z_R1_scratch, Address(method, Method::from_interpreted_offset()));
 561     MacroAssembler::load_and_test_int(Z_R0_scratch, Address(Z_thread, JavaThread::interp_only_mode_offset()));
 562     z_bcr(bcondEqual, Z_R1_scratch); // Run compiled code if zero.
 563     // Run interpreted.
 564     z_lg(Z_R1_scratch, Address(method, Method::interpreter_entry_offset()));
 565     z_br(Z_R1_scratch);
 566   } else {
 567     // Run compiled code.
 568     z_lg(Z_R1_scratch, Address(method, Method::from_interpreted_offset()));
 569     z_br(Z_R1_scratch);
 570   }
 571 }
 572 
 573 #ifdef ASSERT
 574 void InterpreterMacroAssembler::verify_esp(Register Resp, Register Rtemp) {
 575   // About to read or write Resp[0].
 576   // Make sure it is not in the monitors or the TOP_IJAVA_FRAME_ABI.
 577   address reentry = NULL;
 578 
 579   {
 580     // Check if the frame pointer in Z_fp is correct.
 581     NearLabel OK;
 582     z_cg(Z_fp, 0, Z_SP);
 583     z_bre(OK);
 584     reentry = stop_chain_static(reentry, "invalid frame pointer Z_fp");
 585     bind(OK);
 586   }
 587   {
 588     // Resp must not point into or below the operand stack,
 589     // i.e. IJAVA_STATE.monitors > Resp.
 590     NearLabel OK;
 591     Register Rmonitors = Rtemp;
 592     z_lg(Rmonitors, _z_ijava_state_neg(monitors), Z_fp);
 593     compareU64_and_branch(Rmonitors, Resp, bcondHigh, OK);
 594     reentry = stop_chain_static(reentry, "too many pops: Z_esp points into monitor area");
 595     bind(OK);
 596   }
 597   {
 598     // Resp may point to the last word of TOP_IJAVA_FRAME_ABI, but not below
 599     // i.e. !(Z_SP + frame::z_top_ijava_frame_abi_size - Interpreter::stackElementSize > Resp).
 600     NearLabel OK;
 601     Register Rabi_bottom = Rtemp;
 602     add2reg(Rabi_bottom, frame::z_top_ijava_frame_abi_size - Interpreter::stackElementSize, Z_SP);
 603     compareU64_and_branch(Rabi_bottom, Resp, bcondNotHigh, OK);
 604     reentry = stop_chain_static(reentry, "too many pushes: Z_esp points into TOP_IJAVA_FRAME_ABI");
 605     bind(OK);
 606   }
 607 }
 608 
 609 void InterpreterMacroAssembler::asm_assert_ijava_state_magic(Register tmp) {
 610   Label magic_ok;
 611   load_const_optimized(tmp, frame::z_istate_magic_number);
 612   z_cg(tmp, Address(Z_fp, _z_ijava_state_neg(magic)));
 613   z_bre(magic_ok);
 614   stop_static("error: wrong magic number in ijava_state access");
 615   bind(magic_ok);
 616 }
 617 #endif // ASSERT
 618 
 619 void InterpreterMacroAssembler::save_bcp() {
 620   z_stg(Z_bcp, Address(Z_fp, _z_ijava_state_neg(bcp)));
 621   asm_assert_ijava_state_magic(Z_bcp);
 622   NOT_PRODUCT(z_lg(Z_bcp, Address(Z_fp, _z_ijava_state_neg(bcp))));
 623 }
 624 
 625 void InterpreterMacroAssembler::restore_bcp() {
 626   asm_assert_ijava_state_magic(Z_bcp);
 627   z_lg(Z_bcp, Address(Z_fp, _z_ijava_state_neg(bcp)));
 628 }
 629 
 630 void InterpreterMacroAssembler::save_esp() {
 631   z_stg(Z_esp, Address(Z_fp, _z_ijava_state_neg(esp)));
 632 }
 633 
 634 void InterpreterMacroAssembler::restore_esp() {
 635   asm_assert_ijava_state_magic(Z_esp);
 636   z_lg(Z_esp, Address(Z_fp, _z_ijava_state_neg(esp)));
 637 }
 638 
 639 void InterpreterMacroAssembler::get_monitors(Register reg) {
 640   asm_assert_ijava_state_magic(reg);
 641   mem2reg_opt(reg, Address(Z_fp, _z_ijava_state_neg(monitors)));
 642 }
 643 
 644 void InterpreterMacroAssembler::save_monitors(Register reg) {
 645   reg2mem_opt(reg, Address(Z_fp, _z_ijava_state_neg(monitors)));
 646 }
 647 
 648 void InterpreterMacroAssembler::get_mdp(Register mdp) {
 649   z_lg(mdp, _z_ijava_state_neg(mdx), Z_fp);
 650 }
 651 
 652 void InterpreterMacroAssembler::save_mdp(Register mdp) {
 653   z_stg(mdp, _z_ijava_state_neg(mdx), Z_fp);
 654 }
 655 
 656 // Values that are only read (besides initialization).
 657 void InterpreterMacroAssembler::restore_locals() {
 658   asm_assert_ijava_state_magic(Z_locals);
 659   z_lg(Z_locals, Address(Z_fp, _z_ijava_state_neg(locals)));
 660 }
 661 
 662 void InterpreterMacroAssembler::get_method(Register reg) {
 663   asm_assert_ijava_state_magic(reg);
 664   z_lg(reg, Address(Z_fp, _z_ijava_state_neg(method)));
 665 }
 666 
 667 void InterpreterMacroAssembler::get_2_byte_integer_at_bcp(Register Rdst, int bcp_offset,
 668                                                           signedOrNot is_signed) {
 669   // Rdst is an 8-byte return value!!!
 670 
 671   // Unaligned loads incur only a small penalty on z/Architecture. The penalty
 672   // is a few (2..3) ticks, even when the load crosses a cache line
 673   // boundary. In case of a cache miss, the stall could, of course, be
 674   // much longer.
 675 
 676   switch (is_signed) {
 677     case Signed:
 678       z_lgh(Rdst, bcp_offset, Z_R0, Z_bcp);
 679      break;
 680    case Unsigned:
 681      z_llgh(Rdst, bcp_offset, Z_R0, Z_bcp);
 682      break;
 683    default:
 684      ShouldNotReachHere();
 685   }
 686 }
 687 
 688 
 689 void InterpreterMacroAssembler::get_4_byte_integer_at_bcp(Register Rdst, int bcp_offset,
 690                                                           setCCOrNot set_cc) {
 691   // Rdst is an 8-byte return value!!!
 692 
 693   // Unaligned loads incur only a small penalty on z/Architecture. The penalty
 694   // is a few (2..3) ticks, even when the load crosses a cache line
 695   // boundary. In case of a cache miss, the stall could, of course, be
 696   // much longer.
 697 
 698   // Both variants implement a sign-extending int2long load.
 699   if (set_cc == set_CC) {
 700     load_and_test_int2long(Rdst, Address(Z_bcp, (intptr_t)bcp_offset));
 701   } else {
 702     mem2reg_signed_opt(    Rdst, Address(Z_bcp, (intptr_t)bcp_offset));
 703   }
 704 }
 705 
 706 void InterpreterMacroAssembler::get_constant_pool(Register Rdst) {
 707   get_method(Rdst);
 708   mem2reg_opt(Rdst, Address(Rdst, Method::const_offset()));
 709   mem2reg_opt(Rdst, Address(Rdst, ConstMethod::constants_offset()));
 710 }
 711 
 712 void InterpreterMacroAssembler::get_cpool_and_tags(Register Rcpool, Register Rtags) {
 713   get_constant_pool(Rcpool);
 714   mem2reg_opt(Rtags, Address(Rcpool, ConstantPool::tags_offset_in_bytes()));
 715 }
 716 
 717 // Unlock if synchronized method.
 718 //
 719 // Unlock the receiver if this is a synchronized method.
 720 // Unlock any Java monitors from syncronized blocks.
 721 //
 722 // If there are locked Java monitors
 723 //   If throw_monitor_exception
 724 //     throws IllegalMonitorStateException
 725 //   Else if install_monitor_exception
 726 //     installs IllegalMonitorStateException
 727 //   Else
 728 //     no error processing
 729 void InterpreterMacroAssembler::unlock_if_synchronized_method(TosState state,
 730                                                               bool throw_monitor_exception,
 731                                                               bool install_monitor_exception) {
 732   NearLabel unlocked, unlock, no_unlock;
 733 
 734   {
 735     Register R_method = Z_ARG2;
 736     Register R_do_not_unlock_if_synchronized = Z_ARG3;
 737 
 738     // Get the value of _do_not_unlock_if_synchronized into G1_scratch.
 739     const Address do_not_unlock_if_synchronized(Z_thread,
 740                                                 JavaThread::do_not_unlock_if_synchronized_offset());
 741     load_sized_value(R_do_not_unlock_if_synchronized, do_not_unlock_if_synchronized, 1, false /*unsigned*/);
 742     z_mvi(do_not_unlock_if_synchronized, false); // Reset the flag.
 743 
 744     // Check if synchronized method.
 745     get_method(R_method);
 746     verify_oop(Z_tos, state);
 747     push(state); // Save tos/result.
 748     testbit(method2_(R_method, access_flags), JVM_ACC_SYNCHRONIZED_BIT);
 749     z_bfalse(unlocked);
 750 
 751     // Don't unlock anything if the _do_not_unlock_if_synchronized flag
 752     // is set.
 753     compareU64_and_branch(R_do_not_unlock_if_synchronized, (intptr_t)0L, bcondNotEqual, no_unlock);
 754   }
 755 
 756   // unlock monitor
 757 
 758   // BasicObjectLock will be first in list, since this is a
 759   // synchronized method. However, need to check that the object has
 760   // not been unlocked by an explicit monitorexit bytecode.
 761   const Address monitor(Z_fp, -(frame::z_ijava_state_size + (int) sizeof(BasicObjectLock)));
 762   // We use Z_ARG2 so that if we go slow path it will be the correct
 763   // register for unlock_object to pass to VM directly.
 764   load_address(Z_ARG2, monitor); // Address of first monitor.
 765   z_lg(Z_ARG3, Address(Z_ARG2, BasicObjectLock::obj_offset_in_bytes()));
 766   compareU64_and_branch(Z_ARG3, (intptr_t)0L, bcondNotEqual, unlock);
 767 
 768   if (throw_monitor_exception) {
 769     // Entry already unlocked need to throw an exception.
 770     MacroAssembler::call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::throw_illegal_monitor_state_exception));
 771     should_not_reach_here();
 772   } else {
 773     // Monitor already unlocked during a stack unroll.
 774     // If requested, install an illegal_monitor_state_exception.
 775     // Continue with stack unrolling.
 776     if (install_monitor_exception) {
 777       MacroAssembler::call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::new_illegal_monitor_state_exception));
 778     }
 779    z_bru(unlocked);
 780   }
 781 
 782   bind(unlock);
 783 
 784   unlock_object(Z_ARG2);
 785 
 786   bind(unlocked);
 787 
 788   // I0, I1: Might contain return value
 789 
 790   // Check that all monitors are unlocked.
 791   {
 792     NearLabel loop, exception, entry, restart;
 793     const int entry_size = frame::interpreter_frame_monitor_size() * wordSize;
 794     // We use Z_ARG2 so that if we go slow path it will be the correct
 795     // register for unlock_object to pass to VM directly.
 796     Register R_current_monitor = Z_ARG2;
 797     Register R_monitor_block_bot = Z_ARG1;
 798     const Address monitor_block_top(Z_fp, _z_ijava_state_neg(monitors));
 799     const Address monitor_block_bot(Z_fp, -frame::z_ijava_state_size);
 800 
 801     bind(restart);
 802     // Starting with top-most entry.
 803     z_lg(R_current_monitor, monitor_block_top);
 804     // Points to word before bottom of monitor block.
 805     load_address(R_monitor_block_bot, monitor_block_bot);
 806     z_bru(entry);
 807 
 808     // Entry already locked, need to throw exception.
 809     bind(exception);
 810 
 811     if (throw_monitor_exception) {
 812       // Throw exception.
 813       MacroAssembler::call_VM(noreg,
 814                               CAST_FROM_FN_PTR(address, InterpreterRuntime::
 815                                                throw_illegal_monitor_state_exception));
 816       should_not_reach_here();
 817     } else {
 818       // Stack unrolling. Unlock object and install illegal_monitor_exception.
 819       // Unlock does not block, so don't have to worry about the frame.
 820       // We don't have to preserve c_rarg1 since we are going to throw an exception.
 821       unlock_object(R_current_monitor);
 822       if (install_monitor_exception) {
 823         call_VM(noreg, CAST_FROM_FN_PTR(address,
 824                                         InterpreterRuntime::
 825                                         new_illegal_monitor_state_exception));
 826       }
 827       z_bru(restart);
 828     }
 829 
 830     bind(loop);
 831     // Check if current entry is used.
 832     load_and_test_long(Z_R0_scratch, Address(R_current_monitor, BasicObjectLock::obj_offset_in_bytes()));
 833     z_brne(exception);
 834 
 835     add2reg(R_current_monitor, entry_size); // Otherwise advance to next entry.
 836     bind(entry);
 837     compareU64_and_branch(R_current_monitor, R_monitor_block_bot, bcondNotEqual, loop);
 838   }
 839 
 840   bind(no_unlock);
 841   pop(state);
 842   verify_oop(Z_tos, state);
 843 }
 844 
 845 // remove activation
 846 //
 847 // Unlock the receiver if this is a synchronized method.
 848 // Unlock any Java monitors from syncronized blocks.
 849 // Remove the activation from the stack.
 850 //
 851 // If there are locked Java monitors
 852 //   If throw_monitor_exception
 853 //     throws IllegalMonitorStateException
 854 //   Else if install_monitor_exception
 855 //     installs IllegalMonitorStateException
 856 //   Else
 857 //     no error processing
 858 void InterpreterMacroAssembler::remove_activation(TosState state,
 859                                                   Register return_pc,
 860                                                   bool throw_monitor_exception,
 861                                                   bool install_monitor_exception,
 862                                                   bool notify_jvmti) {
 863   BLOCK_COMMENT("remove_activation {");
 864   unlock_if_synchronized_method(state, throw_monitor_exception, install_monitor_exception);
 865 
 866   // Save result (push state before jvmti call and pop it afterwards) and notify jvmti.
 867   notify_method_exit(false, state, notify_jvmti ? NotifyJVMTI : SkipNotifyJVMTI);
 868 
 869   if (StackReservedPages > 0) {
 870     BLOCK_COMMENT("reserved_stack_check:");
 871     // Test if reserved zone needs to be enabled.
 872     Label no_reserved_zone_enabling;
 873 
 874     // Compare frame pointers. There is no good stack pointer, as with stack
 875     // frame compression we can get different SPs when we do calls. A subsequent
 876     // call could have a smaller SP, so that this compare succeeds for an
 877     // inner call of the method annotated with ReservedStack.
 878     z_lg(Z_R0, Address(Z_SP, (intptr_t)_z_abi(callers_sp)));
 879     z_clg(Z_R0, Address(Z_thread, JavaThread::reserved_stack_activation_offset())); // Compare with frame pointer in memory.
 880     z_brl(no_reserved_zone_enabling);
 881 
 882     // Enable reserved zone again, throw stack overflow exception.
 883     call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::enable_stack_reserved_zone), Z_thread);
 884     call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::throw_delayed_StackOverflowError));
 885 
 886     should_not_reach_here();
 887 
 888     bind(no_reserved_zone_enabling);
 889   }
 890 
 891   verify_oop(Z_tos, state);
 892   verify_thread();
 893 
 894   pop_interpreter_frame(return_pc, Z_ARG2, Z_ARG3);
 895   BLOCK_COMMENT("} remove_activation");
 896 }
 897 
 898 // lock object
 899 //
 900 // Registers alive
 901 //   monitor - Address of the BasicObjectLock to be used for locking,
 902 //             which must be initialized with the object to lock.
 903 //   object  - Address of the object to be locked.
 904 void InterpreterMacroAssembler::lock_object(Register monitor, Register object) {
 905 
 906   if (UseHeavyMonitors) {
 907     call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::monitorenter),
 908             monitor, /*check_for_exceptions=*/false);
 909     return;
 910   }
 911 
 912   // template code:
 913   //
 914   // markOop displaced_header = obj->mark().set_unlocked();
 915   // monitor->lock()->set_displaced_header(displaced_header);
 916   // if (Atomic::cmpxchg_ptr(/*ex=*/monitor, /*addr*/obj->mark_addr(), /*cmp*/displaced_header) == displaced_header) {
 917   //   // We stored the monitor address into the object's mark word.
 918   // } else if (THREAD->is_lock_owned((address)displaced_header))
 919   //   // Simple recursive case.
 920   //   monitor->lock()->set_displaced_header(NULL);
 921   // } else {
 922   //   // Slow path.
 923   //   InterpreterRuntime::monitorenter(THREAD, monitor);
 924   // }
 925 
 926   const Register displaced_header = Z_ARG5;
 927   const Register object_mark_addr = Z_ARG4;
 928   const Register current_header   = Z_ARG5;
 929 
 930   NearLabel done;
 931   NearLabel slow_case;
 932 
 933   // markOop displaced_header = obj->mark().set_unlocked();
 934 
 935   // Load markOop from object into displaced_header.
 936   z_lg(displaced_header, oopDesc::mark_offset_in_bytes(), object);
 937 
 938   if (UseBiasedLocking) {
 939     biased_locking_enter(object, displaced_header, Z_R1, Z_R0, done, &slow_case);
 940   }
 941 
 942   // Set displaced_header to be (markOop of object | UNLOCK_VALUE).
 943   z_oill(displaced_header, markOopDesc::unlocked_value);
 944 
 945   // monitor->lock()->set_displaced_header(displaced_header);
 946 
 947   // Initialize the box (Must happen before we update the object mark!).
 948   z_stg(displaced_header, BasicObjectLock::lock_offset_in_bytes() +
 949                           BasicLock::displaced_header_offset_in_bytes(), monitor);
 950 
 951   // if (Atomic::cmpxchg_ptr(/*ex=*/monitor, /*addr*/obj->mark_addr(), /*cmp*/displaced_header) == displaced_header) {
 952 
 953   // Store stack address of the BasicObjectLock (this is monitor) into object.
 954   add2reg(object_mark_addr, oopDesc::mark_offset_in_bytes(), object);
 955 
 956   z_csg(displaced_header, monitor, 0, object_mark_addr);
 957   assert(current_header==displaced_header, "must be same register"); // Identified two registers from z/Architecture.
 958 
 959   z_bre(done);
 960 
 961   // } else if (THREAD->is_lock_owned((address)displaced_header))
 962   //   // Simple recursive case.
 963   //   monitor->lock()->set_displaced_header(NULL);
 964 
 965   // We did not see an unlocked object so try the fast recursive case.
 966 
 967   // Check if owner is self by comparing the value in the markOop of object
 968   // (current_header) with the stack pointer.
 969   z_sgr(current_header, Z_SP);
 970 
 971   assert(os::vm_page_size() > 0xfff, "page size too small - change the constant");
 972 
 973   // The prior sequence "LGR, NGR, LTGR" can be done better
 974   // (Z_R1 is temp and not used after here).
 975   load_const_optimized(Z_R0, (~(os::vm_page_size()-1) | markOopDesc::lock_mask_in_place));
 976   z_ngr(Z_R0, current_header); // AND sets CC (result eq/ne 0)
 977 
 978   // If condition is true we are done and hence we can store 0 in the displaced
 979   // header indicating it is a recursive lock and be done.
 980   z_brne(slow_case);
 981   z_release();  // Membar unnecessary on zarch AND because the above csg does a sync before and after.
 982   z_stg(Z_R0/*==0!*/, BasicObjectLock::lock_offset_in_bytes() +
 983                       BasicLock::displaced_header_offset_in_bytes(), monitor);
 984   z_bru(done);
 985 
 986   // } else {
 987   //   // Slow path.
 988   //   InterpreterRuntime::monitorenter(THREAD, monitor);
 989 
 990   // None of the above fast optimizations worked so we have to get into the
 991   // slow case of monitor enter.
 992   bind(slow_case);
 993 
 994   call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::monitorenter),
 995           monitor, /*check_for_exceptions=*/false);
 996 
 997   // }
 998 
 999   bind(done);
1000 }
1001 
1002 // Unlocks an object. Used in monitorexit bytecode and remove_activation.
1003 //
1004 // Registers alive
1005 //   monitor - address of the BasicObjectLock to be used for locking,
1006 //             which must be initialized with the object to lock.
1007 //
1008 // Throw IllegalMonitorException if object is not locked by current thread.
1009 void InterpreterMacroAssembler::unlock_object(Register monitor, Register object) {
1010 
1011   if (UseHeavyMonitors) {
1012     call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::monitorexit),
1013             monitor, /*check_for_exceptions=*/ true);
1014     return;
1015   }
1016 
1017 // else {
1018   // template code:
1019   //
1020   // if ((displaced_header = monitor->displaced_header()) == NULL) {
1021   //   // Recursive unlock. Mark the monitor unlocked by setting the object field to NULL.
1022   //   monitor->set_obj(NULL);
1023   // } else if (Atomic::cmpxchg_ptr(displaced_header, obj->mark_addr(), monitor) == monitor) {
1024   //   // We swapped the unlocked mark in displaced_header into the object's mark word.
1025   //   monitor->set_obj(NULL);
1026   // } else {
1027   //   // Slow path.
1028   //   InterpreterRuntime::monitorexit(THREAD, monitor);
1029   // }
1030 
1031   const Register displaced_header = Z_ARG4;
1032   const Register current_header   = Z_R1;
1033   Address obj_entry(monitor, BasicObjectLock::obj_offset_in_bytes());
1034   Label done;
1035 
1036   if (object == noreg) {
1037     // In the template interpreter, we must assure that the object
1038     // entry in the monitor is cleared on all paths. Thus we move
1039     // loading up to here, and clear the entry afterwards.
1040     object = Z_ARG3; // Use Z_ARG3 if caller didn't pass object.
1041     z_lg(object, obj_entry);
1042   }
1043 
1044   assert_different_registers(monitor, object, displaced_header, current_header);
1045 
1046   // if ((displaced_header = monitor->displaced_header()) == NULL) {
1047   //   // Recursive unlock. Mark the monitor unlocked by setting the object field to NULL.
1048   //   monitor->set_obj(NULL);
1049 
1050   clear_mem(obj_entry, sizeof(oop));
1051 
1052   if (UseBiasedLocking) {
1053     // The object address from the monitor is in object.
1054     assert(oopDesc::mark_offset_in_bytes() == 0, "offset of _mark is not 0");
1055     biased_locking_exit(object, displaced_header, done);
1056   }
1057 
1058   // Test first if we are in the fast recursive case.
1059   MacroAssembler::load_and_test_long(displaced_header,
1060                                      Address(monitor, BasicObjectLock::lock_offset_in_bytes() +
1061                                                       BasicLock::displaced_header_offset_in_bytes()));
1062   z_bre(done); // displaced_header == 0 -> goto done
1063 
1064   // } else if (Atomic::cmpxchg_ptr(displaced_header, obj->mark_addr(), monitor) == monitor) {
1065   //   // We swapped the unlocked mark in displaced_header into the object's mark word.
1066   //   monitor->set_obj(NULL);
1067 
1068   // If we still have a lightweight lock, unlock the object and be done.
1069 
1070   // The markword is expected to be at offset 0.
1071   assert(oopDesc::mark_offset_in_bytes() == 0, "unlock_object: review code below");
1072 
1073   // We have the displaced header in displaced_header. If the lock is still
1074   // lightweight, it will contain the monitor address and we'll store the
1075   // displaced header back into the object's mark word.
1076   z_lgr(current_header, monitor);
1077   z_csg(current_header, displaced_header, 0, object);
1078   z_bre(done);
1079 
1080   // } else {
1081   //   // Slow path.
1082   //   InterpreterRuntime::monitorexit(THREAD, monitor);
1083 
1084   // The lock has been converted into a heavy lock and hence
1085   // we need to get into the slow case.
1086   z_stg(object, obj_entry);   // Restore object entry, has been cleared above.
1087   call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::monitorexit),
1088           monitor,  /*check_for_exceptions=*/false);
1089 
1090   // }
1091 
1092   bind(done);
1093 }
1094 
1095 void InterpreterMacroAssembler::test_method_data_pointer(Register mdp, Label& zero_continue) {
1096   assert(ProfileInterpreter, "must be profiling interpreter");
1097   load_and_test_long(mdp, Address(Z_fp, _z_ijava_state_neg(mdx)));
1098   z_brz(zero_continue);
1099 }
1100 
1101 // Set the method data pointer for the current bcp.
1102 void InterpreterMacroAssembler::set_method_data_pointer_for_bcp() {
1103   assert(ProfileInterpreter, "must be profiling interpreter");
1104   Label    set_mdp;
1105   Register mdp    = Z_ARG4;
1106   Register method = Z_ARG5;
1107 
1108   get_method(method);
1109   // Test MDO to avoid the call if it is NULL.
1110   load_and_test_long(mdp, method2_(method, method_data));
1111   z_brz(set_mdp);
1112 
1113   call_VM_leaf(CAST_FROM_FN_PTR(address, InterpreterRuntime::bcp_to_di), method, Z_bcp);
1114   // Z_RET: mdi
1115   // Mdo is guaranteed to be non-zero here, we checked for it before the call.
1116   assert(method->is_nonvolatile(), "choose nonvolatile reg or reload from frame");
1117   z_lg(mdp, method2_(method, method_data)); // Must reload, mdp is volatile reg.
1118   add2reg_with_index(mdp, in_bytes(MethodData::data_offset()), Z_RET, mdp);
1119 
1120   bind(set_mdp);
1121   save_mdp(mdp);
1122 }
1123 
1124 void InterpreterMacroAssembler::verify_method_data_pointer() {
1125   assert(ProfileInterpreter, "must be profiling interpreter");
1126 #ifdef ASSERT
1127   NearLabel verify_continue;
1128   Register bcp_expected = Z_ARG3;
1129   Register mdp    = Z_ARG4;
1130   Register method = Z_ARG5;
1131 
1132   test_method_data_pointer(mdp, verify_continue); // If mdp is zero, continue
1133   get_method(method);
1134 
1135   // If the mdp is valid, it will point to a DataLayout header which is
1136   // consistent with the bcp. The converse is highly probable also.
1137   load_sized_value(bcp_expected, Address(mdp, DataLayout::bci_offset()), 2, false /*signed*/);
1138   z_ag(bcp_expected, Address(method, Method::const_offset()));
1139   load_address(bcp_expected, Address(bcp_expected, ConstMethod::codes_offset()));
1140   compareU64_and_branch(bcp_expected, Z_bcp, bcondEqual, verify_continue);
1141   call_VM_leaf(CAST_FROM_FN_PTR(address, InterpreterRuntime::verify_mdp), method, Z_bcp, mdp);
1142   bind(verify_continue);
1143 #endif // ASSERT
1144 }
1145 
1146 void InterpreterMacroAssembler::set_mdp_data_at(Register mdp_in, int constant, Register value) {
1147   assert(ProfileInterpreter, "must be profiling interpreter");
1148   z_stg(value, constant, mdp_in);
1149 }
1150 
1151 void InterpreterMacroAssembler::increment_mdp_data_at(Register mdp_in,
1152                                                       int constant,
1153                                                       Register tmp,
1154                                                       bool decrement) {
1155   assert_different_registers(mdp_in, tmp);
1156   // counter address
1157   Address data(mdp_in, constant);
1158   const int delta = decrement ? -DataLayout::counter_increment : DataLayout::counter_increment;
1159   add2mem_64(Address(mdp_in, constant), delta, tmp);
1160 }
1161 
1162 void InterpreterMacroAssembler::set_mdp_flag_at(Register mdp_in,
1163                                                 int flag_byte_constant) {
1164   assert(ProfileInterpreter, "must be profiling interpreter");
1165   // Set the flag.
1166   z_oi(Address(mdp_in, DataLayout::flags_offset()), flag_byte_constant);
1167 }
1168 
1169 void InterpreterMacroAssembler::test_mdp_data_at(Register mdp_in,
1170                                                  int offset,
1171                                                  Register value,
1172                                                  Register test_value_out,
1173                                                  Label& not_equal_continue) {
1174   assert(ProfileInterpreter, "must be profiling interpreter");
1175   if (test_value_out == noreg) {
1176     z_cg(value, Address(mdp_in, offset));
1177     z_brne(not_equal_continue);
1178   } else {
1179     // Put the test value into a register, so caller can use it:
1180     z_lg(test_value_out, Address(mdp_in, offset));
1181     compareU64_and_branch(test_value_out, value, bcondNotEqual, not_equal_continue);
1182   }
1183 }
1184 
1185 void InterpreterMacroAssembler::update_mdp_by_offset(Register mdp_in, int offset_of_disp) {
1186   update_mdp_by_offset(mdp_in, noreg, offset_of_disp);
1187 }
1188 
1189 void InterpreterMacroAssembler::update_mdp_by_offset(Register mdp_in,
1190                                                      Register dataidx,
1191                                                      int offset_of_disp) {
1192   assert(ProfileInterpreter, "must be profiling interpreter");
1193   Address disp_address(mdp_in, dataidx, offset_of_disp);
1194   Assembler::z_ag(mdp_in, disp_address);
1195   save_mdp(mdp_in);
1196 }
1197 
1198 void InterpreterMacroAssembler::update_mdp_by_constant(Register mdp_in, int constant) {
1199   assert(ProfileInterpreter, "must be profiling interpreter");
1200   add2reg(mdp_in, constant);
1201   save_mdp(mdp_in);
1202 }
1203 
1204 void InterpreterMacroAssembler::update_mdp_for_ret(Register return_bci) {
1205   assert(ProfileInterpreter, "must be profiling interpreter");
1206   assert(return_bci->is_nonvolatile(), "choose nonvolatile reg or save/restore");
1207   call_VM(noreg,
1208           CAST_FROM_FN_PTR(address, InterpreterRuntime::update_mdp_for_ret),
1209           return_bci);
1210 }
1211 
1212 void InterpreterMacroAssembler::profile_taken_branch(Register mdp, Register bumped_count) {
1213   if (ProfileInterpreter) {
1214     Label profile_continue;
1215 
1216     // If no method data exists, go to profile_continue.
1217     // Otherwise, assign to mdp.
1218     test_method_data_pointer(mdp, profile_continue);
1219 
1220     // We are taking a branch. Increment the taken count.
1221     // We inline increment_mdp_data_at to return bumped_count in a register
1222     //increment_mdp_data_at(mdp, in_bytes(JumpData::taken_offset()));
1223     Address data(mdp, JumpData::taken_offset());
1224     z_lg(bumped_count, data);
1225     // 64-bit overflow is very unlikely. Saturation to 32-bit values is
1226     // performed when reading the counts.
1227     add2reg(bumped_count, DataLayout::counter_increment);
1228     z_stg(bumped_count, data); // Store back out
1229 
1230     // The method data pointer needs to be updated to reflect the new target.
1231     update_mdp_by_offset(mdp, in_bytes(JumpData::displacement_offset()));
1232     bind(profile_continue);
1233   }
1234 }
1235 
1236 // Kills Z_R1_scratch.
1237 void InterpreterMacroAssembler::profile_not_taken_branch(Register mdp) {
1238   if (ProfileInterpreter) {
1239     Label profile_continue;
1240 
1241     // If no method data exists, go to profile_continue.
1242     test_method_data_pointer(mdp, profile_continue);
1243 
1244     // We are taking a branch. Increment the not taken count.
1245     increment_mdp_data_at(mdp, in_bytes(BranchData::not_taken_offset()), Z_R1_scratch);
1246 
1247     // The method data pointer needs to be updated to correspond to
1248     // the next bytecode.
1249     update_mdp_by_constant(mdp, in_bytes(BranchData::branch_data_size()));
1250     bind(profile_continue);
1251   }
1252 }
1253 
1254 // Kills: Z_R1_scratch.
1255 void InterpreterMacroAssembler::profile_call(Register mdp) {
1256   if (ProfileInterpreter) {
1257     Label profile_continue;
1258 
1259     // If no method data exists, go to profile_continue.
1260     test_method_data_pointer(mdp, profile_continue);
1261 
1262     // We are making a call. Increment the count.
1263     increment_mdp_data_at(mdp, in_bytes(CounterData::count_offset()));
1264 
1265     // The method data pointer needs to be updated to reflect the new target.
1266     update_mdp_by_constant(mdp, in_bytes(CounterData::counter_data_size()));
1267     bind(profile_continue);
1268   }
1269 }
1270 
1271 void InterpreterMacroAssembler::profile_final_call(Register mdp) {
1272   if (ProfileInterpreter) {
1273     Label profile_continue;
1274 
1275     // If no method data exists, go to profile_continue.
1276     test_method_data_pointer(mdp, profile_continue);
1277 
1278     // We are making a call. Increment the count.
1279     increment_mdp_data_at(mdp, in_bytes(CounterData::count_offset()));
1280 
1281     // The method data pointer needs to be updated to reflect the new target.
1282     update_mdp_by_constant(mdp, in_bytes(VirtualCallData::virtual_call_data_size()));
1283     bind(profile_continue);
1284   }
1285 }
1286 
1287 void InterpreterMacroAssembler::profile_virtual_call(Register receiver,
1288                                                      Register mdp,
1289                                                      Register reg2,
1290                                                      bool receiver_can_be_null) {
1291   if (ProfileInterpreter) {
1292     NearLabel profile_continue;
1293 
1294     // If no method data exists, go to profile_continue.
1295     test_method_data_pointer(mdp, profile_continue);
1296 
1297     NearLabel skip_receiver_profile;
1298     if (receiver_can_be_null) {
1299       NearLabel not_null;
1300       compareU64_and_branch(receiver, (intptr_t)0L, bcondNotEqual, not_null);
1301       // We are making a call. Increment the count for null receiver.
1302       increment_mdp_data_at(mdp, in_bytes(CounterData::count_offset()));
1303       z_bru(skip_receiver_profile);
1304       bind(not_null);
1305     }
1306 
1307     // Record the receiver type.
1308     record_klass_in_profile(receiver, mdp, reg2, true);
1309     bind(skip_receiver_profile);
1310 
1311     // The method data pointer needs to be updated to reflect the new target.
1312     update_mdp_by_constant(mdp, in_bytes(VirtualCallData::virtual_call_data_size()));
1313     bind(profile_continue);
1314   }
1315 }
1316 
1317 // This routine creates a state machine for updating the multi-row
1318 // type profile at a virtual call site (or other type-sensitive bytecode).
1319 // The machine visits each row (of receiver/count) until the receiver type
1320 // is found, or until it runs out of rows. At the same time, it remembers
1321 // the location of the first empty row. (An empty row records null for its
1322 // receiver, and can be allocated for a newly-observed receiver type.)
1323 // Because there are two degrees of freedom in the state, a simple linear
1324 // search will not work; it must be a decision tree. Hence this helper
1325 // function is recursive, to generate the required tree structured code.
1326 // It's the interpreter, so we are trading off code space for speed.
1327 // See below for example code.
1328 void InterpreterMacroAssembler::record_klass_in_profile_helper(
1329                                         Register receiver, Register mdp,
1330                                         Register reg2, int start_row,
1331                                         Label& done, bool is_virtual_call) {
1332   if (TypeProfileWidth == 0) {
1333     if (is_virtual_call) {
1334       increment_mdp_data_at(mdp, in_bytes(CounterData::count_offset()));
1335     }
1336     return;
1337   }
1338 
1339   int last_row = VirtualCallData::row_limit() - 1;
1340   assert(start_row <= last_row, "must be work left to do");
1341   // Test this row for both the receiver and for null.
1342   // Take any of three different outcomes:
1343   //   1. found receiver => increment count and goto done
1344   //   2. found null => keep looking for case 1, maybe allocate this cell
1345   //   3. found something else => keep looking for cases 1 and 2
1346   // Case 3 is handled by a recursive call.
1347   for (int row = start_row; row <= last_row; row++) {
1348     NearLabel next_test;
1349     bool test_for_null_also = (row == start_row);
1350 
1351     // See if the receiver is receiver[n].
1352     int recvr_offset = in_bytes(VirtualCallData::receiver_offset(row));
1353     test_mdp_data_at(mdp, recvr_offset, receiver,
1354                      (test_for_null_also ? reg2 : noreg),
1355                      next_test);
1356     // (Reg2 now contains the receiver from the CallData.)
1357 
1358     // The receiver is receiver[n]. Increment count[n].
1359     int count_offset = in_bytes(VirtualCallData::receiver_count_offset(row));
1360     increment_mdp_data_at(mdp, count_offset);
1361     z_bru(done);
1362     bind(next_test);
1363 
1364     if (test_for_null_also) {
1365       Label found_null;
1366       // Failed the equality check on receiver[n]... Test for null.
1367       z_ltgr(reg2, reg2);
1368       if (start_row == last_row) {
1369         // The only thing left to do is handle the null case.
1370         if (is_virtual_call) {
1371           z_brz(found_null);
1372           // Receiver did not match any saved receiver and there is no empty row for it.
1373           // Increment total counter to indicate polymorphic case.
1374           increment_mdp_data_at(mdp, in_bytes(CounterData::count_offset()));
1375           z_bru(done);
1376           bind(found_null);
1377         } else {
1378           z_brnz(done);
1379         }
1380         break;
1381       }
1382       // Since null is rare, make it be the branch-taken case.
1383       z_brz(found_null);
1384 
1385       // Put all the "Case 3" tests here.
1386       record_klass_in_profile_helper(receiver, mdp, reg2, start_row + 1, done, is_virtual_call);
1387 
1388       // Found a null. Keep searching for a matching receiver,
1389       // but remember that this is an empty (unused) slot.
1390       bind(found_null);
1391     }
1392   }
1393 
1394   // In the fall-through case, we found no matching receiver, but we
1395   // observed the receiver[start_row] is NULL.
1396 
1397   // Fill in the receiver field and increment the count.
1398   int recvr_offset = in_bytes(VirtualCallData::receiver_offset(start_row));
1399   set_mdp_data_at(mdp, recvr_offset, receiver);
1400   int count_offset = in_bytes(VirtualCallData::receiver_count_offset(start_row));
1401   load_const_optimized(reg2, DataLayout::counter_increment);
1402   set_mdp_data_at(mdp, count_offset, reg2);
1403   if (start_row > 0) {
1404     z_bru(done);
1405   }
1406 }
1407 
1408 // Example state machine code for three profile rows:
1409 //   // main copy of decision tree, rooted at row[1]
1410 //   if (row[0].rec == rec) { row[0].incr(); goto done; }
1411 //   if (row[0].rec != NULL) {
1412 //     // inner copy of decision tree, rooted at row[1]
1413 //     if (row[1].rec == rec) { row[1].incr(); goto done; }
1414 //     if (row[1].rec != NULL) {
1415 //       // degenerate decision tree, rooted at row[2]
1416 //       if (row[2].rec == rec) { row[2].incr(); goto done; }
1417 //       if (row[2].rec != NULL) { count.incr(); goto done; } // overflow
1418 //       row[2].init(rec); goto done;
1419 //     } else {
1420 //       // remember row[1] is empty
1421 //       if (row[2].rec == rec) { row[2].incr(); goto done; }
1422 //       row[1].init(rec); goto done;
1423 //     }
1424 //   } else {
1425 //     // remember row[0] is empty
1426 //     if (row[1].rec == rec) { row[1].incr(); goto done; }
1427 //     if (row[2].rec == rec) { row[2].incr(); goto done; }
1428 //     row[0].init(rec); goto done;
1429 //   }
1430 //   done:
1431 
1432 void InterpreterMacroAssembler::record_klass_in_profile(Register receiver,
1433                                                         Register mdp, Register reg2,
1434                                                         bool is_virtual_call) {
1435   assert(ProfileInterpreter, "must be profiling");
1436   Label done;
1437 
1438   record_klass_in_profile_helper(receiver, mdp, reg2, 0, done, is_virtual_call);
1439 
1440   bind (done);
1441 }
1442 
1443 void InterpreterMacroAssembler::profile_ret(Register return_bci, Register mdp) {
1444   if (ProfileInterpreter) {
1445     NearLabel profile_continue;
1446     uint row;
1447 
1448     // If no method data exists, go to profile_continue.
1449     test_method_data_pointer(mdp, profile_continue);
1450 
1451     // Update the total ret count.
1452     increment_mdp_data_at(mdp, in_bytes(CounterData::count_offset()));
1453 
1454     for (row = 0; row < RetData::row_limit(); row++) {
1455       NearLabel next_test;
1456 
1457       // See if return_bci is equal to bci[n]:
1458       test_mdp_data_at(mdp,
1459                        in_bytes(RetData::bci_offset(row)),
1460                        return_bci, noreg,
1461                        next_test);
1462 
1463       // Return_bci is equal to bci[n]. Increment the count.
1464       increment_mdp_data_at(mdp, in_bytes(RetData::bci_count_offset(row)));
1465 
1466       // The method data pointer needs to be updated to reflect the new target.
1467       update_mdp_by_offset(mdp, in_bytes(RetData::bci_displacement_offset(row)));
1468       z_bru(profile_continue);
1469       bind(next_test);
1470     }
1471 
1472     update_mdp_for_ret(return_bci);
1473 
1474     bind(profile_continue);
1475   }
1476 }
1477 
1478 void InterpreterMacroAssembler::profile_null_seen(Register mdp) {
1479   if (ProfileInterpreter) {
1480     Label profile_continue;
1481 
1482     // If no method data exists, go to profile_continue.
1483     test_method_data_pointer(mdp, profile_continue);
1484 
1485     set_mdp_flag_at(mdp, BitData::null_seen_byte_constant());
1486 
1487     // The method data pointer needs to be updated.
1488     int mdp_delta = in_bytes(BitData::bit_data_size());
1489     if (TypeProfileCasts) {
1490       mdp_delta = in_bytes(VirtualCallData::virtual_call_data_size());
1491     }
1492     update_mdp_by_constant(mdp, mdp_delta);
1493 
1494     bind(profile_continue);
1495   }
1496 }
1497 
1498 void InterpreterMacroAssembler::profile_typecheck_failed(Register mdp, Register tmp) {
1499   if (ProfileInterpreter && TypeProfileCasts) {
1500     Label profile_continue;
1501 
1502     // If no method data exists, go to profile_continue.
1503     test_method_data_pointer(mdp, profile_continue);
1504 
1505     int count_offset = in_bytes(CounterData::count_offset());
1506     // Back up the address, since we have already bumped the mdp.
1507     count_offset -= in_bytes(VirtualCallData::virtual_call_data_size());
1508 
1509     // *Decrement* the counter. We expect to see zero or small negatives.
1510     increment_mdp_data_at(mdp, count_offset, tmp, true);
1511 
1512     bind (profile_continue);
1513   }
1514 }
1515 
1516 void InterpreterMacroAssembler::profile_typecheck(Register mdp, Register klass, Register reg2) {
1517   if (ProfileInterpreter) {
1518     Label profile_continue;
1519 
1520     // If no method data exists, go to profile_continue.
1521     test_method_data_pointer(mdp, profile_continue);
1522 
1523     // The method data pointer needs to be updated.
1524     int mdp_delta = in_bytes(BitData::bit_data_size());
1525     if (TypeProfileCasts) {
1526       mdp_delta = in_bytes(VirtualCallData::virtual_call_data_size());
1527 
1528       // Record the object type.
1529       record_klass_in_profile(klass, mdp, reg2, false);
1530     }
1531     update_mdp_by_constant(mdp, mdp_delta);
1532 
1533     bind(profile_continue);
1534   }
1535 }
1536 
1537 void InterpreterMacroAssembler::profile_switch_default(Register mdp) {
1538   if (ProfileInterpreter) {
1539     Label profile_continue;
1540 
1541     // If no method data exists, go to profile_continue.
1542     test_method_data_pointer(mdp, profile_continue);
1543 
1544     // Update the default case count.
1545     increment_mdp_data_at(mdp, in_bytes(MultiBranchData::default_count_offset()));
1546 
1547     // The method data pointer needs to be updated.
1548     update_mdp_by_offset(mdp, in_bytes(MultiBranchData::default_displacement_offset()));
1549 
1550     bind(profile_continue);
1551   }
1552 }
1553 
1554 // Kills: index, scratch1, scratch2.
1555 void InterpreterMacroAssembler::profile_switch_case(Register index,
1556                                                     Register mdp,
1557                                                     Register scratch1,
1558                                                     Register scratch2) {
1559   if (ProfileInterpreter) {
1560     Label profile_continue;
1561     assert_different_registers(index, mdp, scratch1, scratch2);
1562 
1563     // If no method data exists, go to profile_continue.
1564     test_method_data_pointer(mdp, profile_continue);
1565 
1566     // Build the base (index * per_case_size_in_bytes()) +
1567     // case_array_offset_in_bytes().
1568     z_sllg(index, index, exact_log2(in_bytes(MultiBranchData::per_case_size())));
1569     add2reg(index, in_bytes(MultiBranchData::case_array_offset()));
1570 
1571     // Add the calculated base to the mdp -> address of the case' data.
1572     Address case_data_addr(mdp, index);
1573     Register case_data = scratch1;
1574     load_address(case_data, case_data_addr);
1575 
1576     // Update the case count.
1577     increment_mdp_data_at(case_data,
1578                           in_bytes(MultiBranchData::relative_count_offset()),
1579                           scratch2);
1580 
1581     // The method data pointer needs to be updated.
1582     update_mdp_by_offset(mdp,
1583                          index,
1584                          in_bytes(MultiBranchData::relative_displacement_offset()));
1585 
1586     bind(profile_continue);
1587   }
1588 }
1589 
1590 // kills: R0, R1, flags, loads klass from obj (if not null)
1591 void InterpreterMacroAssembler::profile_obj_type(Register obj, Address mdo_addr, Register klass, bool cmp_done) {
1592   NearLabel null_seen, init_klass, do_nothing, do_update;
1593 
1594   // Klass = obj is allowed.
1595   const Register tmp = Z_R1;
1596   assert_different_registers(obj, mdo_addr.base(), tmp, Z_R0);
1597   assert_different_registers(klass, mdo_addr.base(), tmp, Z_R0);
1598 
1599   z_lg(tmp, mdo_addr);
1600   if (cmp_done) {
1601     z_brz(null_seen);
1602   } else {
1603     compareU64_and_branch(obj, (intptr_t)0, Assembler::bcondEqual, null_seen);
1604   }
1605 
1606   verify_oop(obj);
1607   load_klass(klass, obj);
1608 
1609   // Klass seen before, nothing to do (regardless of unknown bit).
1610   z_lgr(Z_R0, tmp);
1611   assert(Immediate::is_uimm(~TypeEntries::type_klass_mask, 16), "or change following instruction");
1612   z_nill(Z_R0, TypeEntries::type_klass_mask & 0xFFFF);
1613   compareU64_and_branch(Z_R0, klass, Assembler::bcondEqual, do_nothing);
1614 
1615   // Already unknown. Nothing to do anymore.
1616   z_tmll(tmp, TypeEntries::type_unknown);
1617   z_brc(Assembler::bcondAllOne, do_nothing);
1618 
1619   z_lgr(Z_R0, tmp);
1620   assert(Immediate::is_uimm(~TypeEntries::type_mask, 16), "or change following instruction");
1621   z_nill(Z_R0, TypeEntries::type_mask & 0xFFFF);
1622   compareU64_and_branch(Z_R0, (intptr_t)0, Assembler::bcondEqual, init_klass);
1623 
1624   // Different than before. Cannot keep accurate profile.
1625   z_oill(tmp, TypeEntries::type_unknown);
1626   z_bru(do_update);
1627 
1628   bind(init_klass);
1629   // Combine klass and null_seen bit (only used if (tmp & type_mask)==0).
1630   z_ogr(tmp, klass);
1631   z_bru(do_update);
1632 
1633   bind(null_seen);
1634   // Set null_seen if obj is 0.
1635   z_oill(tmp, TypeEntries::null_seen);
1636   // fallthru: z_bru(do_update);
1637 
1638   bind(do_update);
1639   z_stg(tmp, mdo_addr);
1640 
1641   bind(do_nothing);
1642 }
1643 
1644 void InterpreterMacroAssembler::profile_arguments_type(Register mdp, Register callee, Register tmp, bool is_virtual) {
1645   if (!ProfileInterpreter) {
1646     return;
1647   }
1648 
1649   assert_different_registers(mdp, callee, tmp);
1650 
1651   if (MethodData::profile_arguments() || MethodData::profile_return()) {
1652     Label profile_continue;
1653 
1654     test_method_data_pointer(mdp, profile_continue);
1655 
1656     int off_to_start = is_virtual ? in_bytes(VirtualCallData::virtual_call_data_size()) : in_bytes(CounterData::counter_data_size());
1657 
1658     z_cliy(in_bytes(DataLayout::tag_offset()) - off_to_start, mdp,
1659            is_virtual ? DataLayout::virtual_call_type_data_tag : DataLayout::call_type_data_tag);
1660     z_brne(profile_continue);
1661 
1662     if (MethodData::profile_arguments()) {
1663       NearLabel done;
1664       int off_to_args = in_bytes(TypeEntriesAtCall::args_data_offset());
1665       add2reg(mdp, off_to_args);
1666 
1667       for (int i = 0; i < TypeProfileArgsLimit; i++) {
1668         if (i > 0 || MethodData::profile_return()) {
1669           // If return value type is profiled we may have no argument to profile.
1670           z_lg(tmp, in_bytes(TypeEntriesAtCall::cell_count_offset())-off_to_args, mdp);
1671           add2reg(tmp, -i*TypeStackSlotEntries::per_arg_count());
1672           compare64_and_branch(tmp, TypeStackSlotEntries::per_arg_count(), Assembler::bcondLow, done);
1673         }
1674         z_lg(tmp, Address(callee, Method::const_offset()));
1675         z_lgh(tmp, Address(tmp, ConstMethod::size_of_parameters_offset()));
1676         // Stack offset o (zero based) from the start of the argument
1677         // list. For n arguments translates into offset n - o - 1 from
1678         // the end of the argument list. But there is an extra slot at
1679         // the top of the stack. So the offset is n - o from Lesp.
1680         z_sg(tmp, Address(mdp, in_bytes(TypeEntriesAtCall::stack_slot_offset(i))-off_to_args));
1681         z_sllg(tmp, tmp, Interpreter::logStackElementSize);
1682         Address stack_slot_addr(tmp, Z_esp);
1683         z_ltg(tmp, stack_slot_addr);
1684 
1685         Address mdo_arg_addr(mdp, in_bytes(TypeEntriesAtCall::argument_type_offset(i))-off_to_args);
1686         profile_obj_type(tmp, mdo_arg_addr, tmp, /*ltg did compare to 0*/ true);
1687 
1688         int to_add = in_bytes(TypeStackSlotEntries::per_arg_size());
1689         add2reg(mdp, to_add);
1690         off_to_args += to_add;
1691       }
1692 
1693       if (MethodData::profile_return()) {
1694         z_lg(tmp, in_bytes(TypeEntriesAtCall::cell_count_offset())-off_to_args, mdp);
1695         add2reg(tmp, -TypeProfileArgsLimit*TypeStackSlotEntries::per_arg_count());
1696       }
1697 
1698       bind(done);
1699 
1700       if (MethodData::profile_return()) {
1701         // We're right after the type profile for the last
1702         // argument. Tmp is the number of cells left in the
1703         // CallTypeData/VirtualCallTypeData to reach its end. Non null
1704         // if there's a return to profile.
1705         assert(ReturnTypeEntry::static_cell_count() < TypeStackSlotEntries::per_arg_count(), "can't move past ret type");
1706         z_sllg(tmp, tmp, exact_log2(DataLayout::cell_size));
1707         z_agr(mdp, tmp);
1708       }
1709       z_stg(mdp, _z_ijava_state_neg(mdx), Z_fp);
1710     } else {
1711       assert(MethodData::profile_return(), "either profile call args or call ret");
1712       update_mdp_by_constant(mdp, in_bytes(TypeEntriesAtCall::return_only_size()));
1713     }
1714 
1715     // Mdp points right after the end of the
1716     // CallTypeData/VirtualCallTypeData, right after the cells for the
1717     // return value type if there's one.
1718     bind(profile_continue);
1719   }
1720 }
1721 
1722 void InterpreterMacroAssembler::profile_return_type(Register mdp, Register ret, Register tmp) {
1723   assert_different_registers(mdp, ret, tmp);
1724   if (ProfileInterpreter && MethodData::profile_return()) {
1725     Label profile_continue;
1726 
1727     test_method_data_pointer(mdp, profile_continue);
1728 
1729     if (MethodData::profile_return_jsr292_only()) {
1730       // If we don't profile all invoke bytecodes we must make sure
1731       // it's a bytecode we indeed profile. We can't go back to the
1732       // beginning of the ProfileData we intend to update to check its
1733       // type because we're right after it and we don't known its
1734       // length.
1735       NearLabel do_profile;
1736       Address bc(Z_bcp);
1737       z_lb(tmp, bc);
1738       compare32_and_branch(tmp, Bytecodes::_invokedynamic, Assembler::bcondEqual, do_profile);
1739       compare32_and_branch(tmp, Bytecodes::_invokehandle, Assembler::bcondEqual, do_profile);
1740       get_method(tmp);
1741       // Supplement to 8139891: _intrinsic_id exceeded 1-byte size limit.
1742       if (Method::intrinsic_id_size_in_bytes() == 1) {
1743         z_cli(Method::intrinsic_id_offset_in_bytes(), tmp, vmIntrinsics::_compiledLambdaForm);
1744       } else {
1745         assert(Method::intrinsic_id_size_in_bytes() == 2, "size error: check Method::_intrinsic_id");
1746         z_lh(tmp, Method::intrinsic_id_offset_in_bytes(), Z_R0, tmp);
1747         z_chi(tmp, vmIntrinsics::_compiledLambdaForm);
1748       }
1749       z_brne(profile_continue);
1750 
1751       bind(do_profile);
1752     }
1753 
1754     Address mdo_ret_addr(mdp, -in_bytes(ReturnTypeEntry::size()));
1755     profile_obj_type(ret, mdo_ret_addr, tmp);
1756 
1757     bind(profile_continue);
1758   }
1759 }
1760 
1761 void InterpreterMacroAssembler::profile_parameters_type(Register mdp, Register tmp1, Register tmp2) {
1762   if (ProfileInterpreter && MethodData::profile_parameters()) {
1763     Label profile_continue, done;
1764 
1765     test_method_data_pointer(mdp, profile_continue);
1766 
1767     // Load the offset of the area within the MDO used for
1768     // parameters. If it's negative we're not profiling any parameters.
1769     Address parm_di_addr(mdp, in_bytes(MethodData::parameters_type_data_di_offset()) - in_bytes(MethodData::data_offset()));
1770     load_and_test_int2long(tmp1, parm_di_addr);
1771     z_brl(profile_continue);
1772 
1773     // Compute a pointer to the area for parameters from the offset
1774     // and move the pointer to the slot for the last
1775     // parameters. Collect profiling from last parameter down.
1776     // mdo start + parameters offset + array length - 1
1777 
1778     // Pointer to the parameter area in the MDO.
1779     z_agr(mdp, tmp1);
1780 
1781     // Offset of the current profile entry to update.
1782     const Register entry_offset = tmp1;
1783     // entry_offset = array len in number of cells.
1784     z_lg(entry_offset, Address(mdp, ArrayData::array_len_offset()));
1785     // entry_offset (number of cells) = array len - size of 1 entry
1786     add2reg(entry_offset, -TypeStackSlotEntries::per_arg_count());
1787     // entry_offset in bytes
1788     z_sllg(entry_offset, entry_offset, exact_log2(DataLayout::cell_size));
1789 
1790     Label loop;
1791     bind(loop);
1792 
1793     Address arg_off(mdp, entry_offset, ParametersTypeData::stack_slot_offset(0));
1794     Address arg_type(mdp, entry_offset, ParametersTypeData::type_offset(0));
1795 
1796     // Load offset on the stack from the slot for this parameter.
1797     z_lg(tmp2, arg_off);
1798     z_sllg(tmp2, tmp2, Interpreter::logStackElementSize);
1799     z_lcgr(tmp2); // Negate.
1800 
1801     // Profile the parameter.
1802     z_ltg(tmp2, Address(Z_locals, tmp2));
1803     profile_obj_type(tmp2, arg_type, tmp2, /*ltg did compare to 0*/ true);
1804 
1805     // Go to next parameter.
1806     z_aghi(entry_offset, -TypeStackSlotEntries::per_arg_count() * DataLayout::cell_size);
1807     z_brnl(loop);
1808 
1809     bind(profile_continue);
1810   }
1811 }
1812 
1813 // Jump if ((*counter_addr += increment) & mask) satisfies the condition.
1814 void InterpreterMacroAssembler::increment_mask_and_jump(Address          counter_addr,
1815                                                         int              increment,
1816                                                         Address          mask,
1817                                                         Register         scratch,
1818                                                         bool             preloaded,
1819                                                         branch_condition cond,
1820                                                         Label           *where) {
1821   assert_different_registers(counter_addr.base(), scratch);
1822   if (preloaded) {
1823     add2reg(scratch, increment);
1824     reg2mem_opt(scratch, counter_addr, false);
1825   } else {
1826     if (VM_Version::has_MemWithImmALUOps() && Immediate::is_simm8(increment) && counter_addr.is_RSYform()) {
1827       z_alsi(counter_addr.disp20(), counter_addr.base(), increment);
1828       mem2reg_signed_opt(scratch, counter_addr);
1829     } else {
1830       mem2reg_signed_opt(scratch, counter_addr);
1831       add2reg(scratch, increment);
1832       reg2mem_opt(scratch, counter_addr, false);
1833     }
1834   }
1835   z_n(scratch, mask);
1836   if (where) { z_brc(cond, *where); }
1837 }
1838 
1839 // Get MethodCounters object for given method. Lazily allocated if necessary.
1840 //   method    - Ptr to Method object.
1841 //   Rcounters - Ptr to MethodCounters object associated with Method object.
1842 //   skip      - Exit point if MethodCounters object can't be created (OOM condition).
1843 void InterpreterMacroAssembler::get_method_counters(Register Rmethod,
1844                                                     Register Rcounters,
1845                                                     Label& skip) {
1846   assert_different_registers(Rmethod, Rcounters);
1847 
1848   BLOCK_COMMENT("get MethodCounters object {");
1849 
1850   Label has_counters;
1851   load_and_test_long(Rcounters, Address(Rmethod, Method::method_counters_offset()));
1852   z_brnz(has_counters);
1853 
1854   call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::build_method_counters), Rmethod, false);
1855   z_ltgr(Rcounters, Z_RET); // Runtime call returns MethodCounters object.
1856   z_brz(skip); // No MethodCounters, out of memory.
1857 
1858   bind(has_counters);
1859 
1860   BLOCK_COMMENT("} get MethodCounters object");
1861 }
1862 
1863 // Increment invocation counter in MethodCounters object.
1864 // Return (invocation_counter+backedge_counter) as "result" in RctrSum.
1865 // Counter values are all unsigned.
1866 void InterpreterMacroAssembler::increment_invocation_counter(Register Rcounters, Register RctrSum) {
1867   assert(UseCompiler || LogTouchedMethods, "incrementing must be useful");
1868   assert_different_registers(Rcounters, RctrSum);
1869 
1870   int increment          = InvocationCounter::count_increment;
1871   int inv_counter_offset = in_bytes(MethodCounters::invocation_counter_offset() + InvocationCounter::counter_offset());
1872   int be_counter_offset  = in_bytes(MethodCounters::backedge_counter_offset()   + InvocationCounter::counter_offset());
1873 
1874   BLOCK_COMMENT("Increment invocation counter {");
1875 
1876   if (VM_Version::has_MemWithImmALUOps() && Immediate::is_simm8(increment)) {
1877     // Increment the invocation counter in place,
1878     // then add the incremented value to the backedge counter.
1879     z_l(RctrSum, be_counter_offset, Rcounters);
1880     z_alsi(inv_counter_offset, Rcounters, increment);     // Atomic increment @no extra cost!
1881     z_nilf(RctrSum, InvocationCounter::count_mask_value); // Mask off state bits.
1882     z_al(RctrSum, inv_counter_offset, Z_R0, Rcounters);
1883   } else {
1884     // This path is optimized for low register consumption
1885     // at the cost of somewhat higher operand delays.
1886     // It does not need an extra temp register.
1887 
1888     // Update the invocation counter.
1889     z_l(RctrSum, inv_counter_offset, Rcounters);
1890     if (RctrSum == Z_R0) {
1891       z_ahi(RctrSum, increment);
1892     } else {
1893       add2reg(RctrSum, increment);
1894     }
1895     z_st(RctrSum, inv_counter_offset, Rcounters);
1896 
1897     // Mask off the state bits.
1898     z_nilf(RctrSum, InvocationCounter::count_mask_value);
1899 
1900     // Add the backedge counter to the updated invocation counter to
1901     // form the result.
1902     z_al(RctrSum, be_counter_offset, Z_R0, Rcounters);
1903   }
1904 
1905   BLOCK_COMMENT("} Increment invocation counter");
1906 
1907   // Note that this macro must leave the backedge_count + invocation_count in Rtmp!
1908 }
1909 
1910 
1911 // increment backedge counter in MethodCounters object.
1912 // return (invocation_counter+backedge_counter) as "result" in RctrSum
1913 // counter values are all unsigned!
1914 void InterpreterMacroAssembler::increment_backedge_counter(Register Rcounters, Register RctrSum) {
1915   assert(UseCompiler, "incrementing must be useful");
1916   assert_different_registers(Rcounters, RctrSum);
1917 
1918   int increment          = InvocationCounter::count_increment;
1919   int inv_counter_offset = in_bytes(MethodCounters::invocation_counter_offset() + InvocationCounter::counter_offset());
1920   int be_counter_offset  = in_bytes(MethodCounters::backedge_counter_offset()   + InvocationCounter::counter_offset());
1921 
1922   BLOCK_COMMENT("Increment backedge counter {");
1923 
1924   if (VM_Version::has_MemWithImmALUOps() && Immediate::is_simm8(increment)) {
1925     // Increment the invocation counter in place,
1926     // then add the incremented value to the backedge counter.
1927     z_l(RctrSum, inv_counter_offset, Rcounters);
1928     z_alsi(be_counter_offset, Rcounters, increment);      // Atomic increment @no extra cost!
1929     z_nilf(RctrSum, InvocationCounter::count_mask_value); // Mask off state bits.
1930     z_al(RctrSum, be_counter_offset, Z_R0, Rcounters);
1931   } else {
1932     // This path is optimized for low register consumption
1933     // at the cost of somewhat higher operand delays.
1934     // It does not need an extra temp register.
1935 
1936     // Update the invocation counter.
1937     z_l(RctrSum, be_counter_offset, Rcounters);
1938     if (RctrSum == Z_R0) {
1939       z_ahi(RctrSum, increment);
1940     } else {
1941       add2reg(RctrSum, increment);
1942     }
1943     z_st(RctrSum, be_counter_offset, Rcounters);
1944 
1945     // Mask off the state bits.
1946     z_nilf(RctrSum, InvocationCounter::count_mask_value);
1947 
1948     // Add the backedge counter to the updated invocation counter to
1949     // form the result.
1950     z_al(RctrSum, inv_counter_offset, Z_R0, Rcounters);
1951   }
1952 
1953   BLOCK_COMMENT("} Increment backedge counter");
1954 
1955   // Note that this macro must leave the backedge_count + invocation_count in Rtmp!
1956 }
1957 
1958 // Add an InterpMonitorElem to stack (see frame_s390.hpp).
1959 void InterpreterMacroAssembler::add_monitor_to_stack(bool     stack_is_empty,
1960                                                      Register Rtemp1,
1961                                                      Register Rtemp2,
1962                                                      Register Rtemp3) {
1963 
1964   const Register Rcurr_slot = Rtemp1;
1965   const Register Rlimit     = Rtemp2;
1966   const jint delta = -frame::interpreter_frame_monitor_size() * wordSize;
1967 
1968   assert((delta & LongAlignmentMask) == 0,
1969          "sizeof BasicObjectLock must be even number of doublewords");
1970   assert(2 * wordSize == -delta, "this works only as long as delta == -2*wordSize");
1971   assert(Rcurr_slot != Z_R0, "Register must be usable as base register");
1972   assert_different_registers(Rlimit, Rcurr_slot, Rtemp3);
1973 
1974   get_monitors(Rlimit);
1975 
1976   // Adjust stack pointer for additional monitor entry.
1977   resize_frame(RegisterOrConstant((intptr_t) delta), Z_fp, false);
1978 
1979   if (!stack_is_empty) {
1980     // Must copy stack contents down.
1981     NearLabel next, done;
1982 
1983     // Rtemp := addr(Tos), Z_esp is pointing below it!
1984     add2reg(Rcurr_slot, wordSize, Z_esp);
1985 
1986     // Nothing to do, if already at monitor area.
1987     compareU64_and_branch(Rcurr_slot, Rlimit, bcondNotLow, done);
1988 
1989     bind(next);
1990 
1991     // Move one stack slot.
1992     mem2reg_opt(Rtemp3, Address(Rcurr_slot));
1993     reg2mem_opt(Rtemp3, Address(Rcurr_slot, delta));
1994     add2reg(Rcurr_slot, wordSize);
1995     compareU64_and_branch(Rcurr_slot, Rlimit, bcondLow, next); // Are we done?
1996 
1997     bind(done);
1998     // Done copying stack.
1999   }
2000 
2001   // Adjust expression stack and monitor pointers.
2002   add2reg(Z_esp, delta);
2003   add2reg(Rlimit, delta);
2004   save_monitors(Rlimit);
2005 }
2006 
2007 // Note: Index holds the offset in bytes afterwards.
2008 // You can use this to store a new value (with Llocals as the base).
2009 void InterpreterMacroAssembler::access_local_int(Register index, Register dst) {
2010   z_sllg(index, index, LogBytesPerWord);
2011   mem2reg_opt(dst, Address(Z_locals, index), false);
2012 }
2013 
2014 void InterpreterMacroAssembler::verify_oop(Register reg, TosState state) {
2015   if (state == atos) { MacroAssembler::verify_oop(reg); }
2016 }
2017 
2018 // Inline assembly for:
2019 //
2020 // if (thread is in interp_only_mode) {
2021 //   InterpreterRuntime::post_method_entry();
2022 // }
2023 
2024 void InterpreterMacroAssembler::notify_method_entry() {
2025 
2026   // JVMTI
2027   // Whenever JVMTI puts a thread in interp_only_mode, method
2028   // entry/exit events are sent for that thread to track stack
2029   // depth. If it is possible to enter interp_only_mode we add
2030   // the code to check if the event should be sent.
2031   if (JvmtiExport::can_post_interpreter_events()) {
2032     Label jvmti_post_done;
2033     MacroAssembler::load_and_test_int(Z_R0, Address(Z_thread, JavaThread::interp_only_mode_offset()));
2034     z_bre(jvmti_post_done);
2035     call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::post_method_entry), /*check_exceptions=*/false);
2036     bind(jvmti_post_done);
2037   }
2038 }
2039 
2040 // Inline assembly for:
2041 //
2042 // if (thread is in interp_only_mode) {
2043 //   if (!native_method) save result
2044 //   InterpreterRuntime::post_method_exit();
2045 //   if (!native_method) restore result
2046 // }
2047 // if (DTraceMethodProbes) {
2048 //   SharedRuntime::dtrace_method_exit(thread, method);
2049 // }
2050 //
2051 // For native methods their result is stored in z_ijava_state.lresult
2052 // and z_ijava_state.fresult before coming here.
2053 // Java methods have their result stored in the expression stack.
2054 //
2055 // Notice the dependency to frame::interpreter_frame_result().
2056 void InterpreterMacroAssembler::notify_method_exit(bool native_method,
2057                                                    TosState state,
2058                                                    NotifyMethodExitMode mode) {
2059   // JVMTI
2060   // Whenever JVMTI puts a thread in interp_only_mode, method
2061   // entry/exit events are sent for that thread to track stack
2062   // depth. If it is possible to enter interp_only_mode we add
2063   // the code to check if the event should be sent.
2064   if (mode == NotifyJVMTI && JvmtiExport::can_post_interpreter_events()) {
2065     Label jvmti_post_done;
2066     MacroAssembler::load_and_test_int(Z_R0, Address(Z_thread, JavaThread::interp_only_mode_offset()));
2067     z_bre(jvmti_post_done);
2068     if (!native_method) push(state); // see frame::interpreter_frame_result()
2069     call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::post_method_exit), /*check_exceptions=*/false);
2070     if (!native_method) pop(state);
2071     bind(jvmti_post_done);
2072   }
2073 
2074 #if 0
2075   // Dtrace currently not supported on z/Architecture.
2076   {
2077     SkipIfEqual skip(this, &DTraceMethodProbes, false);
2078     push(state);
2079     get_method(c_rarg1);
2080     call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_exit),
2081                  r15_thread, c_rarg1);
2082     pop(state);
2083   }
2084 #endif
2085 }
2086 
2087 void InterpreterMacroAssembler::skip_if_jvmti_mode(Label &Lskip, Register Rscratch) {
2088   if (!JvmtiExport::can_post_interpreter_events()) {
2089     return;
2090   }
2091 
2092   load_and_test_int(Rscratch, Address(Z_thread, JavaThread::interp_only_mode_offset()));
2093   z_brnz(Lskip);
2094 
2095 }
2096 
2097 // Pop the topmost TOP_IJAVA_FRAME and set it's sender_sp as new Z_SP.
2098 // The return pc is loaded into the register return_pc.
2099 //
2100 // Registers updated:
2101 //     return_pc  - The return pc of the calling frame.
2102 //     tmp1, tmp2 - scratch
2103 void InterpreterMacroAssembler::pop_interpreter_frame(Register return_pc, Register tmp1, Register tmp2) {
2104   // F0  Z_SP -> caller_sp (F1's)
2105   //             ...
2106   //             sender_sp (F1's)
2107   //             ...
2108   // F1  Z_fp -> caller_sp (F2's)
2109   //             return_pc (Continuation after return from F0.)
2110   //             ...
2111   // F2          caller_sp
2112 
2113   // Remove F0's activation. Restoring Z_SP to sender_sp reverts modifications
2114   // (a) by a c2i adapter and (b) by generate_fixed_frame().
2115   // In case (a) the new top frame F1 is an unextended compiled frame.
2116   // In case (b) F1 is converted from PARENT_IJAVA_FRAME to TOP_IJAVA_FRAME.
2117 
2118   // Case (b) seems to be redundant when returning to a interpreted caller,
2119   // because then the caller's top_frame_sp is installed as sp (see
2120   // TemplateInterpreterGenerator::generate_return_entry_for ()). But
2121   // pop_interpreter_frame() is also used in exception handling and there the
2122   // frame type of the caller is unknown, therefore top_frame_sp cannot be used,
2123   // so it is important that sender_sp is the caller's sp as TOP_IJAVA_FRAME.
2124 
2125   Register R_f1_sender_sp = tmp1;
2126   Register R_f2_sp = tmp2;
2127 
2128   // Tirst check the for the interpreter frame's magic.
2129   asm_assert_ijava_state_magic(R_f2_sp/*tmp*/);
2130   z_lg(R_f2_sp, _z_parent_ijava_frame_abi(callers_sp), Z_fp);
2131   z_lg(R_f1_sender_sp, _z_ijava_state_neg(sender_sp), Z_fp);
2132   if (return_pc->is_valid())
2133     z_lg(return_pc, _z_parent_ijava_frame_abi(return_pc), Z_fp);
2134   // Pop F0 by resizing to R_f1_sender_sp and using R_f2_sp as fp.
2135   resize_frame_absolute(R_f1_sender_sp, R_f2_sp, false/*load fp*/);
2136 
2137 #ifdef ASSERT
2138   // The return_pc in the new top frame is dead... at least that's my
2139   // current understanding; to assert this I overwrite it.
2140   load_const_optimized(Z_ARG3, 0xb00b1);
2141   z_stg(Z_ARG3, _z_parent_ijava_frame_abi(return_pc), Z_SP);
2142 #endif
2143 }
2144 
2145 void InterpreterMacroAssembler::verify_FPU(int stack_depth, TosState state) {
2146   if (VerifyFPU) {
2147     unimplemented("verfiyFPU");
2148   }
2149 }
2150