1 /*
   2  * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright 2012, 2013 SAP AG. 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 #include "precompiled.hpp"
  27 #include "asm/macroAssembler.inline.hpp"
  28 #include "interpreter/interpreter.hpp"
  29 #include "memory/allocation.inline.hpp"
  30 #include "prims/methodHandles.hpp"
  31 
  32 #define __ _masm->
  33 
  34 #ifdef PRODUCT
  35 #define BLOCK_COMMENT(str) // nothing
  36 #define STOP(error) stop(error)
  37 #else
  38 #define BLOCK_COMMENT(str) __ block_comment(str)
  39 #define STOP(error) block_comment(error); __ stop(error)
  40 #endif
  41 
  42 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
  43 
  44 // Workaround for C++ overloading nastiness on '0' for RegisterOrConstant.
  45 inline static RegisterOrConstant constant(int value) {
  46   return RegisterOrConstant(value);
  47 }
  48 
  49 void MethodHandles::load_klass_from_Class(MacroAssembler* _masm, Register klass_reg, Register temp_reg, Register temp2_reg) {
  50   if (VerifyMethodHandles)
  51     verify_klass(_masm, klass_reg, SystemDictionary::WK_KLASS_ENUM_NAME(java_lang_Class), temp_reg, temp2_reg,
  52                  "MH argument is a Class");
  53   __ ld(klass_reg, java_lang_Class::klass_offset_in_bytes(), klass_reg);
  54 }
  55 
  56 #ifdef ASSERT
  57 static int check_nonzero(const char* xname, int x) {
  58   assert(x != 0, err_msg("%s should be nonzero", xname));
  59   return x;
  60 }
  61 #define NONZERO(x) check_nonzero(#x, x)
  62 #else //ASSERT
  63 #define NONZERO(x) (x)
  64 #endif //ASSERT
  65 
  66 #ifdef ASSERT
  67 void MethodHandles::verify_klass(MacroAssembler* _masm,
  68                                  Register obj_reg, SystemDictionary::WKID klass_id,
  69                                  Register temp_reg, Register temp2_reg,
  70                                  const char* error_message) {
  71   Klass** klass_addr = SystemDictionary::well_known_klass_addr(klass_id);
  72   KlassHandle klass = SystemDictionary::well_known_klass(klass_id);
  73   Label L_ok, L_bad;
  74   BLOCK_COMMENT("verify_klass {");
  75   __ verify_oop(obj_reg);
  76   __ cmpdi(CCR0, obj_reg, 0);
  77   __ beq(CCR0, L_bad);
  78   __ load_klass(temp_reg, obj_reg);
  79   __ load_const_optimized(temp2_reg, (address) klass_addr);
  80   __ ld(temp2_reg, 0, temp2_reg);
  81   __ cmpd(CCR0, temp_reg, temp2_reg);
  82   __ beq(CCR0, L_ok);
  83   __ ld(temp_reg, klass->super_check_offset(), temp_reg);
  84   __ cmpd(CCR0, temp_reg, temp2_reg);
  85   __ beq(CCR0, L_ok);
  86   __ BIND(L_bad);
  87   __ stop(error_message);
  88   __ BIND(L_ok);
  89   BLOCK_COMMENT("} verify_klass");
  90 }
  91 
  92 void MethodHandles::verify_ref_kind(MacroAssembler* _masm, int ref_kind, Register member_reg, Register temp) {
  93   Label L;
  94   BLOCK_COMMENT("verify_ref_kind {");
  95   __ load_sized_value(temp, NONZERO(java_lang_invoke_MemberName::flags_offset_in_bytes()), member_reg,
  96                       sizeof(u4), /*is_signed*/ false);
  97   // assert(sizeof(u4) == sizeof(java.lang.invoke.MemberName.flags), "");
  98   __ srwi( temp, temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_SHIFT);
  99   __ andi(temp, temp, java_lang_invoke_MemberName::MN_REFERENCE_KIND_MASK);
 100   __ cmpwi(CCR1, temp, ref_kind);
 101   __ beq(CCR1, L);
 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, Register method, Register target, Register temp,
 117                                             bool for_compiler_entry) {
 118   assert(method == R19_method, "interpreter calling convention");
 119   assert_different_registers(method, target, temp);
 120 
 121   if (!for_compiler_entry && JvmtiExport::can_post_interpreter_events()) {
 122     Label run_compiled_code;
 123     // JVMTI events, such as single-stepping, are implemented partly by avoiding running
 124     // compiled code in threads for which the event is enabled.  Check here for
 125     // interp_only_mode if these events CAN be enabled.
 126     __ verify_thread();
 127     __ lwz(temp, in_bytes(JavaThread::interp_only_mode_offset()), R16_thread);
 128     __ cmplwi(CCR0, temp, 0);
 129     __ beq(CCR0, run_compiled_code);
 130     __ ld(target, in_bytes(Method::interpreter_entry_offset()), R19_method);
 131     __ mtctr(target);
 132     __ bctr();
 133     __ BIND(run_compiled_code);
 134   }
 135 
 136   const ByteSize entry_offset = for_compiler_entry ? Method::from_compiled_offset() :
 137                                                      Method::from_interpreted_offset();
 138   __ ld(target, in_bytes(entry_offset), R19_method);
 139   __ mtctr(target);
 140   __ bctr();
 141 }
 142 
 143 
 144 void MethodHandles::jump_to_lambda_form(MacroAssembler* _masm,
 145                                         Register recv, Register method_temp,
 146                                         Register temp2, Register temp3,
 147                                         bool for_compiler_entry) {
 148   BLOCK_COMMENT("jump_to_lambda_form {");
 149   // This is the initial entry point of a lazy method handle.
 150   // After type checking, it picks up the invoker from the LambdaForm.
 151   assert_different_registers(recv, method_temp, temp2);  // temp3 is only passed on
 152   assert(method_temp == R19_method, "required register for loading method");
 153 
 154   // Load the invoker, as MH -> MH.form -> LF.vmentry
 155   __ verify_oop(recv);
 156   __ load_heap_oop_not_null(method_temp, NONZERO(java_lang_invoke_MethodHandle::form_offset_in_bytes()), recv);
 157   __ verify_oop(method_temp);
 158   __ load_heap_oop_not_null(method_temp, NONZERO(java_lang_invoke_LambdaForm::vmentry_offset_in_bytes()), method_temp);
 159   __ verify_oop(method_temp);
 160   // the following assumes that a Method* is normally compressed in the vmtarget field:
 161   __ ld(method_temp, NONZERO(java_lang_invoke_MemberName::vmtarget_offset_in_bytes()), method_temp);
 162 
 163   if (VerifyMethodHandles && !for_compiler_entry) {
 164     // make sure recv is already on stack
 165     __ ld(temp2, in_bytes(Method::const_offset()), method_temp);
 166     __ load_sized_value(temp2, in_bytes(ConstMethod::size_of_parameters_offset()), temp2,
 167                         sizeof(u2), /*is_signed*/ false);
 168     // assert(sizeof(u2) == sizeof(ConstMethod::_size_of_parameters), "");
 169     Label L;
 170     __ ld(temp2, __ argument_offset(temp2, temp2, 0), R17_tos);
 171     __ cmpd(CCR1, temp2, recv);
 172     __ beq(CCR1, L);
 173     __ stop("receiver not on stack");
 174     __ BIND(L);
 175   }
 176 
 177   jump_from_method_handle(_masm, method_temp, temp2, temp3, for_compiler_entry);
 178   BLOCK_COMMENT("} jump_to_lambda_form");
 179 }
 180 
 181 
 182 
 183 // Code generation
 184 address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* _masm,
 185                                                                 vmIntrinsics::ID iid) {
 186   const bool not_for_compiler_entry = false;  // this is the interpreter entry
 187   assert(is_signature_polymorphic(iid), "expected invoke iid");
 188   if (iid == vmIntrinsics::_invokeGeneric ||
 189       iid == vmIntrinsics::_compiledLambdaForm) {
 190     // Perhaps surprisingly, the symbolic references visible to Java are not directly used.
 191     // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod.
 192     // They all allow an appendix argument.
 193     __ stop("Should not reach here");           // empty stubs make SG sick
 194     return NULL;
 195   }
 196 
 197   Register argbase    = R17_tos; // parameter (preserved)
 198   Register argslot    = R3;
 199   Register temp1      = R6;
 200   Register param_size = R7;
 201 
 202   // here's where control starts out:
 203   __ align(CodeEntryAlignment);
 204   address entry_point = __ pc();
 205 
 206   if (VerifyMethodHandles) {
 207     Label L;
 208     BLOCK_COMMENT("verify_intrinsic_id {");
 209     __ load_sized_value(temp1, Method::intrinsic_id_offset_in_bytes(), R19_method,
 210                         sizeof(u1), /*is_signed*/ false);
 211     // assert(sizeof(u1) == sizeof(Method::_intrinsic_id), "");
 212     __ cmpwi(CCR1, temp1, (int) iid);
 213     __ beq(CCR1, L);
 214     if (iid == vmIntrinsics::_linkToVirtual ||
 215         iid == vmIntrinsics::_linkToSpecial) {
 216       // could do this for all kinds, but would explode assembly code size
 217       trace_method_handle(_masm, "bad Method*:intrinsic_id");
 218     }
 219     __ stop("bad Method*::intrinsic_id");
 220     __ BIND(L);
 221     BLOCK_COMMENT("} verify_intrinsic_id");
 222   }
 223 
 224   // First task:  Find out how big the argument list is.
 225   int ref_kind = signature_polymorphic_intrinsic_ref_kind(iid);
 226   assert(ref_kind != 0 || iid == vmIntrinsics::_invokeBasic, "must be _invokeBasic or a linkTo intrinsic");
 227   if (ref_kind == 0 || MethodHandles::ref_kind_has_receiver(ref_kind)) {
 228     __ ld(param_size, in_bytes(Method::const_offset()), R19_method);
 229     __ load_sized_value(param_size, in_bytes(ConstMethod::size_of_parameters_offset()), param_size,
 230                         sizeof(u2), /*is_signed*/ false);
 231     // assert(sizeof(u2) == sizeof(ConstMethod::_size_of_parameters), "");
 232   } else {
 233     DEBUG_ONLY(param_size = noreg);
 234   }
 235 
 236   Register tmp_mh = noreg;
 237   if (!is_signature_polymorphic_static(iid)) {
 238     __ ld(tmp_mh = temp1, __ argument_offset(param_size, param_size, 0), argbase);
 239     DEBUG_ONLY(param_size = noreg);
 240   }
 241 
 242   if (TraceMethodHandles) {
 243     if (tmp_mh != noreg)
 244       __ mr(R23_method_handle, tmp_mh);  // make stub happy
 245     trace_method_handle_interpreter_entry(_masm, iid);
 246   }
 247 
 248   if (iid == vmIntrinsics::_invokeBasic) {
 249     generate_method_handle_dispatch(_masm, iid, tmp_mh, noreg, not_for_compiler_entry);
 250 
 251   } else {
 252     // Adjust argument list by popping the trailing MemberName argument.
 253     Register tmp_recv = noreg;
 254     if (MethodHandles::ref_kind_has_receiver(ref_kind)) {
 255       // Load the receiver (not the MH; the actual MemberName's receiver) up from the interpreter stack.
 256       __ ld(tmp_recv = temp1, __ argument_offset(param_size, param_size, 0), argbase);
 257       DEBUG_ONLY(param_size = noreg);
 258     }
 259     Register R19_member = R19_method;  // MemberName ptr; incoming method ptr is dead now
 260     __ ld(R19_member, RegisterOrConstant((intptr_t)8), argbase);
 261     __ add(argbase, Interpreter::stackElementSize, argbase);
 262     generate_method_handle_dispatch(_masm, iid, tmp_recv, R19_member, not_for_compiler_entry);
 263   }
 264 
 265   return entry_point;
 266 }
 267 
 268 void MethodHandles::generate_method_handle_dispatch(MacroAssembler* _masm,
 269                                                     vmIntrinsics::ID iid,
 270                                                     Register receiver_reg,
 271                                                     Register member_reg,
 272                                                     bool for_compiler_entry) {
 273   assert(is_signature_polymorphic(iid), "expected invoke iid");
 274   Register temp1 = (for_compiler_entry ? R21_tmp1 : R7);
 275   Register temp2 = (for_compiler_entry ? R22_tmp2 : R8);
 276   Register temp3 = (for_compiler_entry ? R23_tmp3 : R9);
 277   Register temp4 = (for_compiler_entry ? R24_tmp4 : R10);
 278   if (receiver_reg != noreg)  assert_different_registers(temp1, temp2, temp3, temp4, receiver_reg);
 279   if (member_reg   != noreg)  assert_different_registers(temp1, temp2, temp3, temp4, member_reg);
 280 
 281   if (iid == vmIntrinsics::_invokeBasic) {
 282     // indirect through MH.form.vmentry.vmtarget
 283     jump_to_lambda_form(_masm, receiver_reg, R19_method, temp1, temp2, for_compiler_entry);
 284   } else {
 285     // The method is a member invoker used by direct method handles.
 286     if (VerifyMethodHandles) {
 287       // make sure the trailing argument really is a MemberName (caller responsibility)
 288       verify_klass(_masm, member_reg, SystemDictionary::WK_KLASS_ENUM_NAME(MemberName_klass),
 289                    temp1, temp2,
 290                    "MemberName required for invokeVirtual etc.");
 291     }
 292 
 293     Register temp1_recv_klass = temp1;
 294     if (iid != vmIntrinsics::_linkToStatic) {
 295       __ verify_oop(receiver_reg);
 296       if (iid == vmIntrinsics::_linkToSpecial) {
 297         // Don't actually load the klass; just null-check the receiver.
 298         __ null_check_throw(receiver_reg, 0, temp1, StubRoutines::throw_NullPointerException_at_call_entry());
 299       } else {
 300         // load receiver klass itself
 301         __ null_check_throw(receiver_reg, oopDesc::klass_offset_in_bytes(),
 302                                 temp1, StubRoutines::throw_NullPointerException_at_call_entry());
 303         __ load_klass(temp1_recv_klass, receiver_reg);
 304         __ verify_klass_ptr(temp1_recv_klass);
 305       }
 306       BLOCK_COMMENT("check_receiver {");
 307       // The receiver for the MemberName must be in receiver_reg.
 308       // Check the receiver against the MemberName.clazz
 309       if (VerifyMethodHandles && iid == vmIntrinsics::_linkToSpecial) {
 310         // Did not load it above...
 311         __ load_klass(temp1_recv_klass, receiver_reg);
 312         __ verify_klass_ptr(temp1_recv_klass);
 313       }
 314       if (VerifyMethodHandles && iid != vmIntrinsics::_linkToInterface) {
 315         Label L_ok;
 316         Register temp2_defc = temp2;
 317         __ load_heap_oop_not_null(temp2_defc, NONZERO(java_lang_invoke_MemberName::clazz_offset_in_bytes()), member_reg);
 318         load_klass_from_Class(_masm, temp2_defc, temp3, temp4);
 319         __ verify_klass_ptr(temp2_defc);
 320         __ check_klass_subtype(temp1_recv_klass, temp2_defc, temp3, temp4, L_ok);
 321         // If we get here, the type check failed!
 322         __ stop("receiver class disagrees with MemberName.clazz");
 323         __ BIND(L_ok);
 324       }
 325       BLOCK_COMMENT("} check_receiver");
 326     }
 327     if (iid == vmIntrinsics::_linkToSpecial ||
 328         iid == vmIntrinsics::_linkToStatic) {
 329       DEBUG_ONLY(temp1_recv_klass = noreg);  // these guys didn't load the recv_klass
 330     }
 331 
 332     // Live registers at this point:
 333     //  member_reg - MemberName that was the trailing argument
 334     //  temp1_recv_klass - klass of stacked receiver, if needed
 335     //  O5_savedSP - interpreter linkage (if interpreted)
 336     //  O0..O5 - compiler arguments (if compiled)
 337 
 338     Label L_incompatible_class_change_error;
 339     switch (iid) {
 340     case vmIntrinsics::_linkToSpecial:
 341       if (VerifyMethodHandles) {
 342         verify_ref_kind(_masm, JVM_REF_invokeSpecial, member_reg, temp2);
 343       }
 344       __ ld(R19_method, NONZERO(java_lang_invoke_MemberName::vmtarget_offset_in_bytes()), member_reg);
 345       break;
 346 
 347     case vmIntrinsics::_linkToStatic:
 348       if (VerifyMethodHandles) {
 349         verify_ref_kind(_masm, JVM_REF_invokeStatic, member_reg, temp2);
 350       }
 351       __ ld(R19_method, NONZERO(java_lang_invoke_MemberName::vmtarget_offset_in_bytes()), member_reg);
 352       break;
 353 
 354     case vmIntrinsics::_linkToVirtual:
 355     {
 356       // same as TemplateTable::invokevirtual,
 357       // minus the CP setup and profiling:
 358 
 359       if (VerifyMethodHandles) {
 360         verify_ref_kind(_masm, JVM_REF_invokeVirtual, member_reg, temp2);
 361       }
 362 
 363       // pick out the vtable index from the MemberName, and then we can discard it:
 364       Register temp2_index = temp2;
 365       __ ld(temp2_index, NONZERO(java_lang_invoke_MemberName::vmindex_offset_in_bytes()), member_reg);
 366 
 367       if (VerifyMethodHandles) {
 368         Label L_index_ok;
 369         __ cmpdi(CCR1, temp2_index, 0);
 370         __ bge(CCR1, L_index_ok);
 371         __ stop("no virtual index");
 372         __ BIND(L_index_ok);
 373       }
 374 
 375       // Note:  The verifier invariants allow us to ignore MemberName.clazz and vmtarget
 376       // at this point.  And VerifyMethodHandles has already checked clazz, if needed.
 377 
 378       // get target Method* & entry point
 379       __ lookup_virtual_method(temp1_recv_klass, temp2_index, R19_method);
 380       break;
 381     }
 382 
 383     case vmIntrinsics::_linkToInterface:
 384     {
 385       // same as TemplateTable::invokeinterface
 386       // (minus the CP setup and profiling, with different argument motion)
 387       if (VerifyMethodHandles) {
 388         verify_ref_kind(_masm, JVM_REF_invokeInterface, member_reg, temp2);
 389       }
 390 
 391       Register temp2_intf = temp2;
 392       __ load_heap_oop_not_null(temp2_intf, NONZERO(java_lang_invoke_MemberName::clazz_offset_in_bytes()), member_reg);
 393       load_klass_from_Class(_masm, temp2_intf, temp3, temp4);
 394       __ verify_klass_ptr(temp2_intf);
 395 
 396       Register vtable_index = R19_method;
 397       __ ld(vtable_index, NONZERO(java_lang_invoke_MemberName::vmindex_offset_in_bytes()), member_reg);
 398       if (VerifyMethodHandles) {
 399         Label L_index_ok;
 400         __ cmpdi(CCR1, vtable_index, 0);
 401         __ bge(CCR1, L_index_ok);
 402         __ stop("invalid vtable index for MH.invokeInterface");
 403         __ BIND(L_index_ok);
 404       }
 405 
 406       // given intf, index, and recv klass, dispatch to the implementation method
 407       __ lookup_interface_method(temp1_recv_klass, temp2_intf,
 408                                  // note: next two args must be the same:
 409                                  vtable_index, R19_method,
 410                                  temp3, temp4,
 411                                  L_incompatible_class_change_error);
 412       break;
 413     }
 414 
 415     default:
 416       fatal(err_msg_res("unexpected intrinsic %d: %s", iid, vmIntrinsics::name_at(iid)));
 417       break;
 418     }
 419 
 420     // Live at this point:
 421     //   R19_method
 422     //   O5_savedSP (if interpreted)
 423 
 424     // After figuring out which concrete method to call, jump into it.
 425     // Note that this works in the interpreter with no data motion.
 426     // But the compiled version will require that rcx_recv be shifted out.
 427     __ verify_method_ptr(R19_method);
 428     jump_from_method_handle(_masm, R19_method, temp1, temp2, for_compiler_entry);
 429 
 430     if (iid == vmIntrinsics::_linkToInterface) {
 431       __ BIND(L_incompatible_class_change_error);
 432       __ load_const_optimized(temp1, StubRoutines::throw_IncompatibleClassChangeError_entry());
 433       __ mtctr(temp1);
 434       __ bctr();
 435     }
 436   }
 437 }
 438 
 439 #ifndef PRODUCT
 440 void trace_method_handle_stub(const char* adaptername,
 441                               oopDesc* mh,
 442                               intptr_t* entry_sp,
 443                               intptr_t* saved_regs) {
 444 
 445   bool has_mh = (strstr(adaptername, "/static") == NULL &&
 446                  strstr(adaptername, "linkTo") == NULL);    // static linkers don't have MH
 447   const char* mh_reg_name = has_mh ? "R23_method_handle" : "G23";
 448   tty->print_cr("MH %s %s="INTPTR_FORMAT " sp=" INTPTR_FORMAT,
 449                 adaptername, mh_reg_name, (intptr_t) mh, entry_sp);
 450 
 451   if (Verbose) {
 452     tty->print_cr("Registers:");
 453     const int abi_offset = frame::abi_112_size / 8;
 454     for (int i = R3->encoding(); i <= R13->encoding(); i++) {
 455       Register r = as_Register(i);
 456       int count = i - R3->encoding();
 457       // The registers are stored in reverse order on the stack (by save_volatile_gprs(R1_SP, abi_112_size)).
 458       tty->print("%3s=" PTR_FORMAT, r->name(), saved_regs[abi_offset + count]);
 459       if ((count + 1) % 4 == 0) {
 460         tty->cr();
 461       } else {
 462         tty->print(", ");
 463       }
 464     }
 465     tty->cr();
 466 
 467     {
 468       // dumping last frame with frame::describe
 469 
 470       JavaThread* p = JavaThread::active();
 471 
 472       ResourceMark rm;
 473       PRESERVE_EXCEPTION_MARK; // may not be needed by safer and unexpensive here
 474       FrameValues values;
 475 
 476       // Note: We want to allow trace_method_handle from any call site.
 477       // While trace_method_handle creates a frame, it may be entered
 478       // without a PC on the stack top (e.g. not just after a call).
 479       // Walking that frame could lead to failures due to that invalid PC.
 480       // => carefully detect that frame when doing the stack walking
 481 
 482       // Current C frame
 483       frame cur_frame = os::current_frame();
 484 
 485       // Robust search of trace_calling_frame (independant of inlining).
 486       // Assumes saved_regs comes from a pusha in the trace_calling_frame.
 487       assert(cur_frame.sp() < saved_regs, "registers not saved on stack ?");
 488       frame trace_calling_frame = os::get_sender_for_C_frame(&cur_frame);
 489       while (trace_calling_frame.fp() < saved_regs) {
 490         trace_calling_frame = os::get_sender_for_C_frame(&trace_calling_frame);
 491       }
 492 
 493       // safely create a frame and call frame::describe
 494       intptr_t *dump_sp = trace_calling_frame.sender_sp();
 495 
 496       frame dump_frame = frame(dump_sp);
 497       dump_frame.describe(values, 1);
 498 
 499       values.describe(-1, saved_regs, "raw top of stack");
 500 
 501       tty->print_cr("Stack layout:");
 502       values.print(p);
 503     }
 504 
 505     if (has_mh && mh->is_oop()) {
 506       mh->print();
 507       if (java_lang_invoke_MethodHandle::is_instance(mh)) {
 508         if (java_lang_invoke_MethodHandle::form_offset_in_bytes() != 0)
 509           java_lang_invoke_MethodHandle::form(mh)->print();
 510       }
 511     }
 512   }
 513 }
 514 
 515 void MethodHandles::trace_method_handle(MacroAssembler* _masm, const char* adaptername) {
 516   if (!TraceMethodHandles) return;
 517 
 518   BLOCK_COMMENT("trace_method_handle {");
 519 
 520   int nbytes_save = 10 * 8;             // 10 volatile gprs
 521   __ save_LR_CR(R0);
 522   __ mr(R0, R1_SP);                     // saved_sp
 523   assert(Assembler::is_simm(-nbytes_save, 16), "Overwriting R0");
 524   // push_frame_abi112 only uses R0 if nbytes_save is wider than 16 bit
 525   __ push_frame_abi112(nbytes_save, R0);
 526   __ save_volatile_gprs(R1_SP, frame::abi_112_size); // Except R0.
 527 
 528   __ load_const(R3_ARG1, (address)adaptername);
 529   __ mr(R4_ARG2, R23_method_handle);
 530   __ mr(R5_ARG3, R0);        // saved_sp
 531   __ mr(R6_ARG4, R1_SP);
 532   __ call_VM_leaf(CAST_FROM_FN_PTR(address, trace_method_handle_stub));
 533 
 534   __ restore_volatile_gprs(R1_SP, 112); // except R0
 535   __ pop_frame();
 536   __ restore_LR_CR(R0);
 537 
 538   BLOCK_COMMENT("} trace_method_handle");
 539 }
 540 #endif // PRODUCT