1 /*
   2  * Copyright (c) 2008, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 // This file mirror as much as possible methodHandles_x86.cpp to ease
  26 // cross platform development for JSR292.
  27 // Last synchronization: changeset f8c9417e3571
  28 
  29 #include "precompiled.hpp"
  30 #include "jvm.h"
  31 #include "classfile/javaClasses.inline.hpp"
  32 #include "interpreter/interpreter.hpp"
  33 #include "interpreter/interpreterRuntime.hpp"
  34 #include "memory/allocation.inline.hpp"
  35 #include "memory/resourceArea.hpp"
  36 #include "prims/methodHandles.hpp"
  37 #include "runtime/frame.inline.hpp"
  38 #include "utilities/preserveException.hpp"
  39 
  40 #define __ _masm->
  41 
  42 #ifdef PRODUCT
  43 #define BLOCK_COMMENT(str) /* nothing */
  44 #else
  45 #define BLOCK_COMMENT(str) __ block_comment(str)
  46 #endif
  47 
  48 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
  49 
  50 void MethodHandles::load_klass_from_Class(MacroAssembler* _masm, Register klass_reg, Register temp1, Register temp2) {
  51   if (VerifyMethodHandles) {
  52     verify_klass(_masm, klass_reg, temp1, temp2, SystemDictionary::WK_KLASS_ENUM_NAME(java_lang_Class),
  53                  "MH argument is a Class");
  54   }
  55   __ ldr(klass_reg, Address(klass_reg, java_lang_Class::klass_offset_in_bytes()));
  56 }
  57 
  58 #ifdef ASSERT
  59 static int check_nonzero(const char* xname, int x) {
  60   assert(x != 0, "%s should be nonzero", xname);
  61   return x;
  62 }
  63 #define NONZERO(x) check_nonzero(#x, x)
  64 #else //ASSERT
  65 #define NONZERO(x) (x)
  66 #endif //ASSERT
  67 
  68 #ifdef ASSERT
  69 void MethodHandles::verify_klass(MacroAssembler* _masm,
  70                                  Register obj, Register temp1, Register temp2, SystemDictionary::WKID klass_id,
  71                                  const char* error_message) {
  72   InstanceKlass** klass_addr = SystemDictionary::well_known_klass_addr(klass_id);
  73   Klass* klass = SystemDictionary::well_known_klass(klass_id);
  74   Label L_ok, L_bad;
  75   BLOCK_COMMENT("verify_klass {");
  76   __ verify_oop(obj);
  77   __ cbz(obj, L_bad);
  78   __ load_klass(temp1, obj);
  79   __ lea(temp2, ExternalAddress((address) klass_addr));
  80   __ ldr(temp2, temp2); // the cmpptr on x86 dereferences the AddressLiteral (not lea)
  81   __ cmp(temp1, temp2);
  82   __ b(L_ok, eq);
  83   intptr_t super_check_offset = klass->super_check_offset();
  84   __ ldr(temp1, Address(temp1, super_check_offset));
  85   __ cmp(temp1, temp2);
  86   __ b(L_ok, eq);
  87 
  88   __ bind(L_bad);
  89   __ stop(error_message);
  90   __ BIND(L_ok);
  91   BLOCK_COMMENT("} verify_klass");
  92 }
  93 
  94 void MethodHandles::verify_ref_kind(MacroAssembler* _masm, int ref_kind, Register member_reg, Register temp) {
  95   Label L;
  96   BLOCK_COMMENT("verify_ref_kind {");
  97   __ ldr_u32(temp, Address(member_reg, NONZERO(java_lang_invoke_MemberName::flags_offset_in_bytes())));
  98   __ logical_shift_right(temp, temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT);
  99   __ andr(temp, temp, (unsigned)java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK);
 100   __ cmp(temp, ref_kind);
 101   __ b(L, eq);
 102   { char* buf = NEW_C_HEAP_ARRAY(char, 100, mtInternal);
 103   jio_snprintf(buf, 100, "verify_ref_kind expected %x", ref_kind);
 104   if (ref_kind == JVM_REF_invokeVirtual ||
 105       ref_kind == JVM_REF_invokeSpecial)
 106     // could do this for all ref_kinds, but would explode assembly code size
 107     trace_method_handle(_masm, buf);
 108   __ stop(buf);
 109   }
 110   BLOCK_COMMENT("} verify_ref_kind");
 111   __ bind(L);
 112 }
 113 
 114 #endif //ASSERT
 115 
 116 void MethodHandles::jump_from_method_handle(MacroAssembler* _masm, bool for_compiler_entry) {
 117   Label L_no_such_method;
 118   __ cbz(Rmethod, L_no_such_method);
 119 
 120   // Note: JVMTI overhead seems small enough compared to invocation
 121   // cost and is not worth the complexity or code size overhead of
 122   // supporting several variants of each adapter.
 123   if (!for_compiler_entry && (JvmtiExport::can_post_interpreter_events())) {
 124     // JVMTI events, such as single-stepping, are implemented partly by avoiding running
 125     // compiled code in threads for which the event is enabled.  Check here for
 126     // interp_only_mode if these events CAN be enabled.
 127     __ ldr_s32(Rtemp, Address(Rthread, JavaThread::interp_only_mode_offset()));
 128 #ifdef AARCH64
 129     Label L;
 130     __ cbz(Rtemp, L);
 131     __ indirect_jump(Address(Rmethod, Method::interpreter_entry_offset()), Rtemp);
 132     __ bind(L);
 133 #else
 134     __ cmp(Rtemp, 0);
 135     __ ldr(PC, Address(Rmethod, Method::interpreter_entry_offset()), ne);
 136 #endif // AARCH64
 137   }
 138   const ByteSize entry_offset = for_compiler_entry ? Method::from_compiled_offset() :
 139                                                      Method::from_interpreted_offset();
 140 
 141   __ indirect_jump(Address(Rmethod, entry_offset), Rtemp);
 142 
 143   __ bind(L_no_such_method);
 144   // throw exception
 145   __ jump(StubRoutines::throw_AbstractMethodError_entry(), relocInfo::runtime_call_type, Rtemp);
 146 }
 147 
 148 void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm,
 149                                         Register recv, Register tmp,
 150                                         bool for_compiler_entry) {
 151   BLOCK_COMMENT("jump_to_lambda_form {");
 152   // This is the initial entry point of a lazy method handle.
 153   // After type checking, it picks up the invoker from the LambdaForm.
 154   assert_different_registers(recv, tmp, Rmethod);
 155 
 156   // Load the invoker, as MH -> MH.form -> LF.vmentry
 157   __ load_heap_oop(tmp, Address(recv, NONZERO(java_lang_invoke_MethodHandle::form_offset_in_bytes())));
 158   __ verify_oop(tmp);
 159 
 160   __ load_heap_oop(tmp, Address(tmp, NONZERO(java_lang_invoke_LambdaForm::vmentry_offset_in_bytes())));
 161   __ verify_oop(tmp);
 162 
 163   __ load_heap_oop(Rmethod, Address(tmp, NONZERO(java_lang_invoke_MemberName::method_offset_in_bytes())));
 164   __ verify_oop(Rmethod);
 165   __ access_load_at(T_ADDRESS, IN_HEAP, Address(Rmethod, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset_in_bytes())), Rmethod, noreg, noreg, noreg);
 166 
 167   if (VerifyMethodHandles && !for_compiler_entry) {
 168     // make sure recv is already on stack
 169     __ ldr(tmp, Address(Rmethod, Method::const_offset()));
 170     __ load_sized_value(tmp,
 171                         Address(tmp, ConstMethod::size_of_parameters_offset()),
 172                         sizeof(u2), /*is_signed*/ false);
 173     // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
 174     Label L;
 175     __ ldr(tmp, __ receiver_argument_address(Rparams, tmp, tmp));
 176     __ cmp(tmp, recv);
 177     __ b(L, eq);
 178     __ stop("receiver not on stack");
 179     __ bind(L);
 180   }
 181 
 182   jump_from_method_handle(_masm, for_compiler_entry);
 183   BLOCK_COMMENT("} jump_to_lambda_form");
 184 }
 185 
 186 
 187 // Code generation
 188 address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,
 189                                                                 vmIntrinsics::ID iid) {
 190   const bool not_for_compiler_entry = false;  // this is the interpreter entry
 191   assert(is_signature_polymorphic(iid), "expected invoke iid");
 192   if (iid == vmIntrinsics::_invokeGeneric ||
 193       iid == vmIntrinsics::_compiledLambdaForm) {
 194     // Perhaps surprisingly, the user-visible names, and linkToCallSite, are not directly used.
 195     // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod.
 196     // They all require an extra argument.
 197     __ should_not_reach_here();           // empty stubs make SG sick
 198     return NULL;
 199   }
 200 
 201   // Rmethod: Method*
 202   // Rparams (SP on 32-bit ARM): pointer to parameters
 203   // Rsender_sp (R4/R19): sender SP (must preserve; see prepare_to_jump_from_interpreted)
 204   // R5_mh: receiver method handle (must load from sp[MethodTypeForm.vmslots])
 205   // R1, R2, Rtemp: garbage temp, blown away
 206 
 207   // Use same name as x86 to ease future merges
 208   Register rdx_temp       = R2_tmp;
 209   Register rdx_param_size = rdx_temp;  // size of parameters
 210   Register rax_temp       = R1_tmp;
 211   Register rcx_mh         = R5_mh;     // MH receiver; dies quickly and is recycled
 212   Register rbx_method     = Rmethod;   // eventual target of this invocation
 213   Register rdi_temp       = Rtemp;
 214 
 215   // here's where control starts out:
 216   __ align(CodeEntryAlignment);
 217   address entry_point = __ pc();
 218 
 219   if (VerifyMethodHandles) {
 220     Label L;
 221     BLOCK_COMMENT("verify_intrinsic_id {");
 222     __ ldrh(rdi_temp, Address(rbx_method, Method::intrinsic_id_offset_in_bytes()));
 223     __ sub_slow(rdi_temp, rdi_temp, (int) iid);
 224     __ cbz(rdi_temp, L);
 225     if (iid == vmIntrinsics::_linkToVirtual ||
 226         iid == vmIntrinsics::_linkToSpecial) {
 227       // could do this for all kinds, but would explode assembly code size
 228       trace_method_handle(_masm, "bad Method*::intrinsic_id");
 229     }
 230     __ stop("bad Method*::intrinsic_id");
 231     __ bind(L);
 232     BLOCK_COMMENT("} verify_intrinsic_id");
 233   }
 234 
 235   // First task:  Find out how big the argument list is.
 236   Address rdx_first_arg_addr;
 237   int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);
 238   assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic, "must be _invokeBasic or a linkTo intrinsic");
 239   if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {
 240     __ ldr(rdx_param_size, Address(rbx_method, Method::const_offset()));
 241     __ load_sized_value(rdx_param_size,
 242                         Address(rdx_param_size, ConstMethod::size_of_parameters_offset()),
 243                         sizeof(u2), /*is_signed*/ false);
 244     // assert(sizeof(u2) == sizeof(Method::_size_of_parameters), "");
 245     rdx_first_arg_addr = __ receiver_argument_address(Rparams, rdx_param_size, rdi_temp);
 246   } else {
 247     DEBUG_ONLY(rdx_param_size = noreg);
 248   }
 249 
 250   if (!is_signature_polymorphic_static(iid)) {
 251     __ ldr(rcx_mh, rdx_first_arg_addr);
 252     DEBUG_ONLY(rdx_param_size = noreg);
 253   }
 254 
 255   // rdx_first_arg_addr is live!
 256 
 257   trace_method_handle_interpreter_entry(_masm, iid);
 258 
 259   if (iid == vmIntrinsics::_invokeBasic) {
 260     generate_method_handle_dispatch(_masm, iid, rcx_mh, noreg, not_for_compiler_entry);
 261 
 262   } else {
 263     // Adjust argument list by popping the trailing MemberName argument.
 264     Register rcx_recv = noreg;
 265     if (MethodHandles::ref_kind_has_receiver(ref_kind)) {
 266       // Load the receiver (not the MH; the actual MemberName's receiver) up from the interpreter stack.
 267       __ ldr(rcx_recv = rcx_mh, rdx_first_arg_addr);
 268       DEBUG_ONLY(rdx_param_size = noreg);
 269     }
 270     Register rbx_member = rbx_method;  // MemberName ptr; incoming method ptr is dead now
 271 #ifdef AARCH64
 272     __ ldr(rbx_member, Address(Rparams, Interpreter::stackElementSize, post_indexed));
 273 #else
 274     __ pop(rbx_member);
 275 #endif
 276     generate_method_handle_dispatch(_masm, iid, rcx_recv, rbx_member, not_for_compiler_entry);
 277   }
 278   return entry_point;
 279 }
 280 
 281 void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm,
 282                                                     vmIntrinsics::ID iid,
 283                                                     Register receiver_reg,
 284                                                     Register member_reg,
 285                                                     bool for_compiler_entry) {
 286   assert(is_signature_polymorphic(iid), "expected invoke iid");
 287   // Use same name as x86 to ease future merges
 288   Register rbx_method = Rmethod;   // eventual target of this invocation
 289   // temps used in this code are not used in *either* compiled or interpreted calling sequences
 290   Register temp1 = (for_compiler_entry ? saved_last_sp_register() : R1_tmp);
 291   Register temp2 = AARCH64_ONLY(R9) NOT_AARCH64(R8);
 292   Register temp3 = Rtemp; // R12/R16
 293   Register temp4 = AARCH64_ONLY(Rtemp2) NOT_AARCH64(R5);
 294   if (for_compiler_entry) {
 295     assert(receiver_reg == (iid == vmIntrinsics::_linkToStatic ? noreg : j_rarg0), "only valid assignment");
 296 #ifdef AARCH64
 297     assert_different_registers(temp1, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
 298     assert_different_registers(temp2, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
 299     assert_different_registers(temp3, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
 300     assert_different_registers(temp4, j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5, j_rarg6, j_rarg7);
 301 #else
 302     assert_different_registers(temp1, j_rarg0, j_rarg1, j_rarg2, j_rarg3);
 303     assert_different_registers(temp2, j_rarg0, j_rarg1, j_rarg2, j_rarg3);
 304     assert_different_registers(temp3, j_rarg0, j_rarg1, j_rarg2, j_rarg3);
 305     assert_different_registers(temp4, j_rarg0, j_rarg1, j_rarg2, j_rarg3);
 306 #endif // AARCH64
 307   }
 308   assert_different_registers(temp1, temp2, temp3, receiver_reg);
 309   assert_different_registers(temp1, temp2, temp3, temp4, member_reg);
 310   if (!for_compiler_entry)
 311     assert_different_registers(temp1, temp2, temp3, temp4, saved_last_sp_register());  // don't trash lastSP
 312 
 313   if (iid == vmIntrinsics::_invokeBasic) {
 314     // indirect through MH.form.exactInvoker.vmtarget
 315     jump_to_lambda_form(_masm, receiver_reg, temp3, for_compiler_entry);
 316 
 317   } else {
 318     // The method is a member invoker used by direct method handles.
 319     if (VerifyMethodHandles) {
 320       // make sure the trailing argument really is a MemberName (caller responsibility)
 321       verify_klass(_masm, member_reg, temp2, temp3, SystemDictionary::WK_KLASS_ENUM_NAME(java_lang_invoke_MemberName),
 322                    "MemberName required for invokeVirtual etc.");
 323     }
 324 
 325     Address member_clazz(   member_reg, NONZERO(java_lang_invoke_MemberName::clazz_offset_in_bytes()));
 326     Address member_vmindex( member_reg, NONZERO(java_lang_invoke_MemberName::vmindex_offset_in_bytes()));
 327     Address member_vmtarget(member_reg, NONZERO(java_lang_invoke_MemberName::method_offset_in_bytes()));
 328     Address vmtarget_method(Rmethod, NONZERO(java_lang_invoke_ResolvedMethodName::vmtarget_offset_in_bytes()));
 329 
 330     Register temp1_recv_klass = temp1;
 331     if (iid != vmIntrinsics::_linkToStatic) {
 332       if (iid == vmIntrinsics::_linkToSpecial) {
 333         // Don't actually load the klass; just null-check the receiver.
 334         __ null_check(receiver_reg, temp3);
 335       } else {
 336         // load receiver klass itself
 337         __ null_check(receiver_reg, temp3, oopDesc::klass_offset_in_bytes());
 338         __ load_klass(temp1_recv_klass, receiver_reg);
 339         __ verify_klass_ptr(temp1_recv_klass);
 340       }
 341       BLOCK_COMMENT("check_receiver {");
 342       // The receiver for the MemberName must be in receiver_reg.
 343       // Check the receiver against the MemberName.clazz
 344       if (VerifyMethodHandles && iid == vmIntrinsics::_linkToSpecial) {
 345         // Did not load it above...
 346         __ load_klass(temp1_recv_klass, receiver_reg);
 347         __ verify_klass_ptr(temp1_recv_klass);
 348       }
 349       // Check the receiver against the MemberName.clazz
 350       if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) {
 351         Label L_ok;
 352         Register temp2_defc = temp2;
 353         __ load_heap_oop(temp2_defc, member_clazz);
 354         load_klass_from_Class(_masm, temp2_defc, temp3, temp4);
 355         __ verify_klass_ptr(temp2_defc);
 356 #ifdef AARCH64
 357         // TODO-AARCH64
 358         __ b(L_ok);
 359 #else
 360         __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, temp4, noreg, L_ok);
 361 #endif
 362         // If we get here, the type check failed!
 363         __ stop("receiver class disagrees with MemberName.clazz");
 364         __ bind(L_ok);
 365       }
 366       BLOCK_COMMENT("} check_receiver");
 367     }
 368     if (iid == vmIntrinsics::_linkToSpecial ||
 369         iid == vmIntrinsics::_linkToStatic) {
 370       DEBUG_ONLY(temp1_recv_klass = noreg);  // these guys didn't load the recv_klass
 371     }
 372 
 373     // Live registers at this point:
 374     //  member_reg - MemberName that was the extra argument
 375     //  temp1_recv_klass - klass of stacked receiver, if needed
 376 
 377     Label L_incompatible_class_change_error;
 378     switch (iid) {
 379     case vmIntrinsics::_linkToSpecial:
 380       if (VerifyMethodHandles) {
 381         verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp3);
 382       }
 383       __ load_heap_oop(Rmethod, member_vmtarget);
 384       __ access_load_at(T_ADDRESS, IN_HEAP, vmtarget_method, Rmethod, noreg, noreg, noreg);
 385       break;
 386 
 387     case vmIntrinsics::_linkToStatic:
 388       if (VerifyMethodHandles) {
 389         verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp3);
 390       }
 391       __ load_heap_oop(Rmethod, member_vmtarget);
 392       __ access_load_at(T_ADDRESS, IN_HEAP, vmtarget_method, Rmethod, noreg, noreg, noreg);
 393       break;
 394       break;
 395 
 396     case vmIntrinsics::_linkToVirtual:
 397     {
 398       // same as TemplateTable::invokevirtual,
 399       // minus the CP setup and profiling:
 400 
 401       if (VerifyMethodHandles) {
 402         verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp3);
 403       }
 404 
 405       // pick out the vtable index from the MemberName, and then we can discard it:
 406       Register temp2_index = temp2;
 407       __ access_load_at(T_ADDRESS, IN_HEAP, member_vmindex, temp2_index, noreg, noreg, noreg);
 408 
 409       if (VerifyMethodHandles) {
 410         Label L_index_ok;
 411         __ cmp(temp2_index, 0);
 412         __ b(L_index_ok, ge);
 413         __ stop("no virtual index");
 414         __ bind(L_index_ok);
 415       }
 416 
 417       // Note:  The verifier invariants allow us to ignore MemberName.clazz and vmtarget
 418       // at this point.  And VerifyMethodHandles has already checked clazz, if needed.
 419 
 420       // get target Method* & entry point
 421       __ lookup_virtual_method(temp1_recv_klass, temp2_index, Rmethod);
 422       break;
 423     }
 424 
 425     case vmIntrinsics::_linkToInterface:
 426     {
 427       // same as TemplateTable::invokeinterface
 428       // (minus the CP setup and profiling, with different argument motion)
 429       if (VerifyMethodHandles) {
 430         verify_ref_kind(_masm, JVM_REF_invokeInterface, member_reg, temp3);
 431       }
 432 
 433       Register temp3_intf = temp3;
 434       __ load_heap_oop(temp3_intf, member_clazz);
 435       load_klass_from_Class(_masm, temp3_intf, temp2, temp4);
 436       __ verify_klass_ptr(temp3_intf);
 437 
 438       Register rbx_index = rbx_method;
 439       __ access_load_at(T_ADDRESS, IN_HEAP, member_vmindex, rbx_index, noreg, noreg, noreg);
 440       if (VerifyMethodHandles) {
 441         Label L;
 442         __ cmp(rbx_index, 0);
 443         __ b(L, ge);
 444         __ stop("invalid vtable index for MH.invokeInterface");
 445         __ bind(L);
 446       }
 447 
 448       // given intf, index, and recv klass, dispatch to the implementation method
 449       Label L_no_such_interface;
 450       __ lookup_interface_method(temp1_recv_klass, temp3_intf,
 451                                  // note: next two args must be the same:
 452                                  rbx_index, rbx_method,
 453                                  temp2, temp4,
 454                                  L_incompatible_class_change_error);
 455       break;
 456     }
 457 
 458     default:
 459       fatal("unexpected intrinsic %d: %s", iid, vmIntrinsics::name_at(iid));
 460       break;
 461     }
 462 
 463     // Live at this point:
 464     //   Rmethod (target method)
 465     //   Rsender_sp, Rparams (if interpreted)
 466     //   register arguments (if compiled)
 467 
 468     // After figuring out which concrete method to call, jump into it.
 469     __ verify_method_ptr(Rmethod);
 470     jump_from_method_handle(_masm, for_compiler_entry);
 471 
 472     if (iid == vmIntrinsics::_linkToInterface) {
 473       __ bind(L_incompatible_class_change_error);
 474       __ jump(StubRoutines::throw_IncompatibleClassChangeError_entry(), relocInfo::runtime_call_type, Rtemp);
 475     }
 476   }
 477 }
 478 
 479 
 480 #ifndef PRODUCT
 481 enum {
 482   ARG_LIMIT = 255, SLOP = 4,
 483   // use this parameter for checking for garbage stack movements:
 484   UNREASONABLE_STACK_MOVE = (ARG_LIMIT + SLOP)
 485   // the slop defends against false alarms due to fencepost errors
 486 };
 487 
 488 #ifdef AARCH64
 489 const int trace_mh_nregs = 32; // R0-R30, PC
 490 #else
 491 const int trace_mh_nregs = 15;
 492 const Register trace_mh_regs[trace_mh_nregs] =
 493   {R0, R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, LR, PC};
 494 #endif // AARCH64
 495 
 496 void trace_method_handle_stub(const char* adaptername,
 497                               intptr_t* saved_regs,
 498                               intptr_t* saved_bp,
 499                               oop mh) {
 500   // called as a leaf from native code: do not block the JVM!
 501   bool has_mh = (strstr(adaptername, "/static") == NULL &&
 502                  strstr(adaptername, "linkTo") == NULL);    // static linkers don't have MH
 503   intptr_t* entry_sp = (intptr_t*) &saved_regs[trace_mh_nregs]; // just after the saved regs
 504   intptr_t* saved_sp = (intptr_t*)  saved_regs[Rsender_sp->encoding()]; // save of Rsender_sp
 505   intptr_t* last_sp  = (intptr_t*)  saved_bp[AARCH64_ONLY(frame::interpreter_frame_stack_top_offset) NOT_AARCH64(frame::interpreter_frame_last_sp_offset)];
 506   intptr_t* base_sp  = last_sp;
 507 
 508   intptr_t    mh_reg = (intptr_t)saved_regs[R5_mh->encoding()];
 509   const char* mh_reg_name = "R5_mh";
 510   if (!has_mh)  mh_reg_name = "R5";
 511   tty->print_cr("MH %s %s=" PTR_FORMAT " sp=(" PTR_FORMAT "+" INTX_FORMAT ") stack_size=" INTX_FORMAT " bp=" PTR_FORMAT,
 512                 adaptername, mh_reg_name, mh_reg,
 513                 (intptr_t)entry_sp, (intptr_t)saved_sp - (intptr_t)entry_sp, (intptr_t)(base_sp - last_sp), (intptr_t)saved_bp);
 514 
 515   if (last_sp != saved_sp && last_sp != NULL)
 516     tty->print_cr("*** last_sp=" INTPTR_FORMAT, p2i(last_sp));
 517   if (Verbose) {
 518     tty->print(" reg dump: ");
 519     int i;
 520     for (i = 0; i < trace_mh_nregs; i++) {
 521       if (i > 0 && i % AARCH64_ONLY(2) NOT_AARCH64(4) == 0)
 522         tty->print("\n   + dump: ");
 523 #ifdef AARCH64
 524       const char* reg_name = (i == trace_mh_nregs-1) ? "pc" : as_Register(i)->name();
 525 #else
 526       const char* reg_name = trace_mh_regs[i]->name();
 527 #endif
 528       tty->print(" %s: " INTPTR_FORMAT, reg_name, p2i((void *)saved_regs[i]));
 529     }
 530     tty->cr();
 531   }
 532 
 533   if (Verbose) {
 534     // dump last frame (from JavaThread::print_frame_layout)
 535 
 536     // Note: code is robust but the dumped informationm may not be
 537     // 100% correct, particularly with respect to the dumped
 538     // "unextended_sp". Getting it right for all trace_method_handle
 539     // call paths is not worth the complexity/risk. The correct slot
 540     // will be identified by *Rsender_sp anyway in the dump.
 541     JavaThread* p = JavaThread::active();
 542 
 543     ResourceMark rm;
 544     PRESERVE_EXCEPTION_MARK;
 545     FrameValues values;
 546 
 547     intptr_t* dump_fp = (intptr_t *) saved_bp;
 548     address dump_pc = (address) saved_regs[trace_mh_nregs-2]; // LR (with LR,PC last in saved_regs)
 549     frame dump_frame((intptr_t *)entry_sp, dump_fp, dump_pc);
 550 
 551     dump_frame.describe(values, 1);
 552     // mark Rsender_sp if seems valid
 553     if (has_mh) {
 554       if ((saved_sp >= entry_sp - UNREASONABLE_STACK_MOVE) && (saved_sp < dump_fp)) {
 555         values.describe(-1, saved_sp, "*Rsender_sp");
 556       }
 557     }
 558 
 559     // Note: the unextended_sp may not be correct
 560     tty->print_cr("  stack layout:");
 561     values.print(p);
 562   }
 563   if (Verbose) {
 564     if (has_mh && oopDesc::is_oop(mh)) {
 565       mh->print();
 566       if (java_lang_invoke_MethodHandle::is_instance(mh)) {
 567         if (java_lang_invoke_MethodHandle::form_offset_in_bytes() != 0)
 568           java_lang_invoke_MethodHandle::form(mh)->print();
 569       }
 570     }
 571   }
 572 }
 573 
 574 void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) {
 575   if (!TraceMethodHandles)  return;
 576   BLOCK_COMMENT("trace_method_handle {");
 577   // register saving
 578   //  must correspond to trace_mh_nregs and trace_mh_regs defined above
 579   int push_size = __ save_all_registers();
 580   assert(trace_mh_nregs*wordSize == push_size,"saved register count mismatch");
 581 
 582   __ mov_slow(R0, adaptername);
 583   __ mov(R1, SP); // entry_sp (after pushes)
 584   __ mov(R2, FP);
 585   if (R5_mh != R3) {
 586     assert_different_registers(R0, R1, R2, R5_mh);
 587     __ mov(R3, R5_mh);
 588   }
 589 
 590   __ call_VM_leaf(CAST_FROM_FN_PTR(address, trace_method_handle_stub), R0, R1, R2, R3);
 591 
 592   __ restore_all_registers();
 593   BLOCK_COMMENT("} trace_method_handle");
 594 }
 595 #endif //PRODUCT