Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  *

  */

 #include "precompiled.hpp"

 #include "asm/assembler.hpp"

 #include "assembler_x86.inline.hpp"

 #include "code/debugInfoRec.hpp"

 #include "code/icBuffer.hpp"

 #include "code/vtableStubs.hpp"

 #include "interpreter/interpreter.hpp"

 #include "oops/compiledICHolderOop.hpp"

 #include "prims/jvmtiRedefineClassesTrace.hpp"

 #include "runtime/sharedRuntime.hpp"

 #include "runtime/vframeArray.hpp"

 #include "vmreg_x86.inline.hpp"

 #ifdef COMPILER1

 #include "c1/c1_Runtime1.hpp"

 #endif

 #ifdef COMPILER2

 #include "opto/runtime.hpp"

 #endif

 #define __ masm->

 const int StackAlignmentInSlots = StackAlignmentInBytes / VMRegImpl::stack_slot_size;

 class SimpleRuntimeFrame {

   public:

   // Most of the runtime stubs have this simple frame layout.

   // This class exists to make the layout shared in one place.

   // Offsets are for compiler stack slots, which are jints.

   enum layout {

     // The frame sender code expects that rbp will be in the "natural" place and

     // will override any oopMap setting for it. We must therefore force the layout

     // so that it agrees with the frame sender code.

     rbp_off = frame::arg_reg_save_area_bytes/BytesPerInt,

     rbp_off2,

     return_off, return_off2,

     framesize

   };

 };

 class RegisterSaver {

   // Capture info about frame layout.  Layout offsets are in jint

   // units because compiler frame slots are jints.

 #define DEF_XMM_OFFS(regnum) xmm ## regnum ## _off = xmm_off + (regnum)*16/BytesPerInt, xmm ## regnum ## H_off

   enum layout {

     fpu_state_off = frame::arg_reg_save_area_bytes/BytesPerInt, // fxsave save area

     xmm_off       = fpu_state_off + 160/BytesPerInt,            // offset in fxsave save area

     DEF_XMM_OFFS(0),

     DEF_XMM_OFFS(1),

     DEF_XMM_OFFS(2),

     DEF_XMM_OFFS(3),

     DEF_XMM_OFFS(4),

     DEF_XMM_OFFS(5),

     DEF_XMM_OFFS(6),

     DEF_XMM_OFFS(7),

     DEF_XMM_OFFS(8),

     DEF_XMM_OFFS(9),

     DEF_XMM_OFFS(10),

     DEF_XMM_OFFS(11),

     DEF_XMM_OFFS(12),

     DEF_XMM_OFFS(13),

     DEF_XMM_OFFS(14),

     DEF_XMM_OFFS(15),

     fpu_state_end = fpu_state_off + ((FPUStateSizeInWords-1)*wordSize / BytesPerInt),

     fpu_stateH_end,

     r15_off, r15H_off,

     r14_off, r14H_off,

     r13_off, r13H_off,

     r12_off, r12H_off,

     r11_off, r11H_off,

     r10_off, r10H_off,

     r9_off,  r9H_off,

     r8_off,  r8H_off,

     rdi_off, rdiH_off,

     rsi_off, rsiH_off,

     ignore_off, ignoreH_off,  // extra copy of rbp

     rsp_off, rspH_off,

     rbx_off, rbxH_off,

     rdx_off, rdxH_off,

     rcx_off, rcxH_off,

     rax_off, raxH_off,

     // 16-byte stack alignment fill word: see MacroAssembler::push/pop_IU_state

     align_off, alignH_off,

     flags_off, flagsH_off,

     // The frame sender code expects that rbp will be in the "natural" place and

     // will override any oopMap setting for it. We must therefore force the layout

     // so that it agrees with the frame sender code.

     rbp_off, rbpH_off,        // copy of rbp we will restore

     return_off, returnH_off,  // slot for return address

     reg_save_size             // size in compiler stack slots

   };

  public:

   static OopMap* save_live_registers(MacroAssembler* masm, int additional_frame_words, int* total_frame_words);

   static void restore_live_registers(MacroAssembler* masm);

   // Offsets into the register save area

   // Used by deoptimization when it is managing result register

   // values on its own

   static int rax_offset_in_bytes(void)    { return BytesPerInt * rax_off; }

   static int rdx_offset_in_bytes(void)    { return BytesPerInt * rdx_off; }

   static int rbx_offset_in_bytes(void)    { return BytesPerInt * rbx_off; }

   static int xmm0_offset_in_bytes(void)   { return BytesPerInt * xmm0_off; }

   static int return_offset_in_bytes(void) { return BytesPerInt * return_off; }

   // During deoptimization only the result registers need to be restored,

   // all the other values have already been extracted.

   static void restore_result_registers(MacroAssembler* masm);

 };

 OopMap* RegisterSaver::save_live_registers(MacroAssembler* masm, int additional_frame_words, int* total_frame_words) {

   // Always make the frame size 16-byte aligned

   int frame_size_in_bytes = round_to(additional_frame_words*wordSize +

                                      reg_save_size*BytesPerInt, 16);

   // OopMap frame size is in compiler stack slots (jint's) not bytes or words

   int frame_size_in_slots = frame_size_in_bytes / BytesPerInt;

   // The caller will allocate additional_frame_words

   int additional_frame_slots = additional_frame_words*wordSize / BytesPerInt;

   // CodeBlob frame size is in words.

   int frame_size_in_words = frame_size_in_bytes / wordSize;

   *total_frame_words = frame_size_in_words;

   // Save registers, fpu state, and flags.

   // We assume caller has already pushed the return address onto the

   // stack, so rsp is 8-byte aligned here.

   // We push rpb twice in this sequence because we want the real rbp

   // to be under the return like a normal enter.

   __ enter();          // rsp becomes 16-byte aligned here

   __ push_CPU_state(); // Push a multiple of 16 bytes

   if (frame::arg_reg_save_area_bytes != 0) {

     // Allocate argument register save area

     __ subptr(rsp, frame::arg_reg_save_area_bytes);

   }

   // Set an oopmap for the call site.  This oopmap will map all

   // oop-registers and debug-info registers as callee-saved.  This

   // will allow deoptimization at this safepoint to find all possible

   // debug-info recordings, as well as let GC find all oops.

   OopMapSet *oop_maps = new OopMapSet();

   OopMap* map = new OopMap(frame_size_in_slots, 0);

   map->set_callee_saved(VMRegImpl::stack2reg( rax_off  + additional_frame_slots), rax->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg( rcx_off  + additional_frame_slots), rcx->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg( rdx_off  + additional_frame_slots), rdx->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg( rbx_off  + additional_frame_slots), rbx->as_VMReg());

   // rbp location is known implicitly by the frame sender code, needs no oopmap

   // and the location where rbp was saved by is ignored

   map->set_callee_saved(VMRegImpl::stack2reg( rsi_off  + additional_frame_slots), rsi->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg( rdi_off  + additional_frame_slots), rdi->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg( r8_off   + additional_frame_slots), r8->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg( r9_off   + additional_frame_slots), r9->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg( r10_off  + additional_frame_slots), r10->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg( r11_off  + additional_frame_slots), r11->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg( r12_off  + additional_frame_slots), r12->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg( r13_off  + additional_frame_slots), r13->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg( r14_off  + additional_frame_slots), r14->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg( r15_off  + additional_frame_slots), r15->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg(xmm0_off  + additional_frame_slots), xmm0->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg(xmm1_off  + additional_frame_slots), xmm1->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg(xmm2_off  + additional_frame_slots), xmm2->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg(xmm3_off  + additional_frame_slots), xmm3->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg(xmm4_off  + additional_frame_slots), xmm4->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg(xmm5_off  + additional_frame_slots), xmm5->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg(xmm6_off  + additional_frame_slots), xmm6->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg(xmm7_off  + additional_frame_slots), xmm7->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg(xmm8_off  + additional_frame_slots), xmm8->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg(xmm9_off  + additional_frame_slots), xmm9->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg(xmm10_off + additional_frame_slots), xmm10->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg(xmm11_off + additional_frame_slots), xmm11->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg(xmm12_off + additional_frame_slots), xmm12->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg(xmm13_off + additional_frame_slots), xmm13->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg(xmm14_off + additional_frame_slots), xmm14->as_VMReg());

   map->set_callee_saved(VMRegImpl::stack2reg(xmm15_off + additional_frame_slots), xmm15->as_VMReg());

   // %%% These should all be a waste but we'll keep things as they were for now

   if (true) {

     map->set_callee_saved(VMRegImpl::stack2reg( raxH_off  + additional_frame_slots),

                           rax->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg( rcxH_off  + additional_frame_slots),

                           rcx->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg( rdxH_off  + additional_frame_slots),

                           rdx->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg( rbxH_off  + additional_frame_slots),

                           rbx->as_VMReg()->next());

     // rbp location is known implicitly by the frame sender code, needs no oopmap

     map->set_callee_saved(VMRegImpl::stack2reg( rsiH_off  + additional_frame_slots),

                           rsi->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg( rdiH_off  + additional_frame_slots),

                           rdi->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg( r8H_off   + additional_frame_slots),

                           r8->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg( r9H_off   + additional_frame_slots),

                           r9->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg( r10H_off  + additional_frame_slots),

                           r10->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg( r11H_off  + additional_frame_slots),

                           r11->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg( r12H_off  + additional_frame_slots),

                           r12->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg( r13H_off  + additional_frame_slots),

                           r13->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg( r14H_off  + additional_frame_slots),

                           r14->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg( r15H_off  + additional_frame_slots),

                           r15->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg(xmm0H_off  + additional_frame_slots),

                           xmm0->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg(xmm1H_off  + additional_frame_slots),

                           xmm1->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg(xmm2H_off  + additional_frame_slots),

                           xmm2->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg(xmm3H_off  + additional_frame_slots),

                           xmm3->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg(xmm4H_off  + additional_frame_slots),

                           xmm4->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg(xmm5H_off  + additional_frame_slots),

                           xmm5->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg(xmm6H_off  + additional_frame_slots),

                           xmm6->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg(xmm7H_off  + additional_frame_slots),

                           xmm7->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg(xmm8H_off  + additional_frame_slots),

                           xmm8->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg(xmm9H_off  + additional_frame_slots),

                           xmm9->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg(xmm10H_off + additional_frame_slots),

                           xmm10->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg(xmm11H_off + additional_frame_slots),

                           xmm11->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg(xmm12H_off + additional_frame_slots),

                           xmm12->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg(xmm13H_off + additional_frame_slots),

                           xmm13->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg(xmm14H_off + additional_frame_slots),

                           xmm14->as_VMReg()->next());

     map->set_callee_saved(VMRegImpl::stack2reg(xmm15H_off + additional_frame_slots),

                           xmm15->as_VMReg()->next());

   }

   return map;

 }

 void RegisterSaver::restore_live_registers(MacroAssembler* masm) {

   if (frame::arg_reg_save_area_bytes != 0) {

     // Pop arg register save area

     __ addptr(rsp, frame::arg_reg_save_area_bytes);

   }

   // Recover CPU state

   __ pop_CPU_state();

   // Get the rbp described implicitly by the calling convention (no oopMap)

   __ pop(rbp);

 }

 void RegisterSaver::restore_result_registers(MacroAssembler* masm) {

   // Just restore result register. Only used by deoptimization. By

   // now any callee save register that needs to be restored to a c2

   // caller of the deoptee has been extracted into the vframeArray

   // and will be stuffed into the c2i adapter we create for later

   // restoration so only result registers need to be restored here.

   // Restore fp result register

   __ movdbl(xmm0, Address(rsp, xmm0_offset_in_bytes()));

   // Restore integer result register

   __ movptr(rax, Address(rsp, rax_offset_in_bytes()));

   __ movptr(rdx, Address(rsp, rdx_offset_in_bytes()));

   // Pop all of the register save are off the stack except the return address

   __ addptr(rsp, return_offset_in_bytes());

 }

 // The java_calling_convention describes stack locations as ideal slots on

 // a frame with no abi restrictions. Since we must observe abi restrictions

 // (like the placement of the register window) the slots must be biased by

 // the following value.

 static int reg2offset_in(VMReg r) {

   // Account for saved rbp and return address

   // This should really be in_preserve_stack_slots

   return (r->reg2stack() + 4) * VMRegImpl::stack_slot_size;

 }

 static int reg2offset_out(VMReg r) {

   return (r->reg2stack() + SharedRuntime::out_preserve_stack_slots()) * VMRegImpl::stack_slot_size;

 }

 // ---------------------------------------------------------------------------

 // Read the array of BasicTypes from a signature, and compute where the

 // arguments should go.  Values in the VMRegPair regs array refer to 4-byte

 // quantities.  Values less than VMRegImpl::stack0 are registers, those above

 // refer to 4-byte stack slots.  All stack slots are based off of the stack pointer

 // as framesizes are fixed.

 // VMRegImpl::stack0 refers to the first slot 0(sp).

 // and VMRegImpl::stack0+1 refers to the memory word 4-byes higher.  Register

 // up to RegisterImpl::number_of_registers) are the 64-bit

 // integer registers.

 // Note: the INPUTS in sig_bt are in units of Java argument words, which are

 // either 32-bit or 64-bit depending on the build.  The OUTPUTS are in 32-bit

 // units regardless of build. Of course for i486 there is no 64 bit build

 // The Java calling convention is a "shifted" version of the C ABI.

 // By skipping the first C ABI register we can call non-static jni methods

 // with small numbers of arguments without having to shuffle the arguments

 // at all. Since we control the java ABI we ought to at least get some

 // advantage out of it.

 int SharedRuntime::java_calling_convention(const BasicType *sig_bt,

                                            VMRegPair *regs,

                                            int total_args_passed,

                                            int is_outgoing) {

   // Create the mapping between argument positions and

   // registers.

   static const Register INT_ArgReg[Argument::n_int_register_parameters_j] = {

     j_rarg0, j_rarg1, j_rarg2, j_rarg3, j_rarg4, j_rarg5

   };

   static const XMMRegister FP_ArgReg[Argument::n_float_register_parameters_j] = {

     j_farg0, j_farg1, j_farg2, j_farg3,

     j_farg4, j_farg5, j_farg6, j_farg7

   };

   uint int_args = 0;

   uint fp_args = 0;

   uint stk_args = 0; // inc by 2 each time

   for (int i = 0; i < total_args_passed; i++) {

     switch (sig_bt[i]) {

     case T_BOOLEAN:

     case T_CHAR:

     case T_BYTE:

     case T_SHORT:

     case T_INT:

       if (int_args < Argument::n_int_register_parameters_j) {

         regs[i].set1(INT_ArgReg[int_args++]->as_VMReg());

       } else {

         regs[i].set1(VMRegImpl::stack2reg(stk_args));

         stk_args += 2;

       }

       break;

     case T_VOID:

       // halves of T_LONG or T_DOUBLE

       assert(i != 0 && (sig_bt[i - 1] == T_LONG || sig_bt[i - 1] == T_DOUBLE), "expecting half");

       regs[i].set_bad();

       break;

     case T_LONG:

       assert(sig_bt[i + 1] == T_VOID, "expecting half");

       // fall through

     case T_OBJECT:

     case T_ARRAY:

     case T_ADDRESS:

       if (int_args < Argument::n_int_register_parameters_j) {

         regs[i].set2(INT_ArgReg[int_args++]->as_VMReg());

       } else {

         regs[i].set2(VMRegImpl::stack2reg(stk_args));

         stk_args += 2;

       }

       break;

     case T_FLOAT:

       if (fp_args < Argument::n_float_register_parameters_j) {

         regs[i].set1(FP_ArgReg[fp_args++]->as_VMReg());

       } else {

         regs[i].set1(VMRegImpl::stack2reg(stk_args));

         stk_args += 2;

       }

       break;

     case T_DOUBLE:

       assert(sig_bt[i + 1] == T_VOID, "expecting half");

       if (fp_args < Argument::n_float_register_parameters_j) {

         regs[i].set2(FP_ArgReg[fp_args++]->as_VMReg());

       } else {

         regs[i].set2(VMRegImpl::stack2reg(stk_args));

         stk_args += 2;

       }

       break;

     default:

       ShouldNotReachHere();

       break;

     }

   }

   return round_to(stk_args, 2);

 }

 // Patch the callers callsite with entry to compiled code if it exists.

 static void patch_callers_callsite(MacroAssembler *masm) {

   Label L;

   __ verify_oop(rbx);

   __ cmpptr(Address(rbx, in_bytes(methodOopDesc::code_offset())), (int32_t)NULL_WORD);

   __ jcc(Assembler::equal, L);

   // Save the current stack pointer

   __ mov(r13, rsp);

   // Schedule the branch target address early.

   // Call into the VM to patch the caller, then jump to compiled callee

   // rax isn't live so capture return address while we easily can

   __ movptr(rax, Address(rsp, 0));

   // align stack so push_CPU_state doesn't fault

   __ andptr(rsp, -(StackAlignmentInBytes));

   __ push_CPU_state();

   __ verify_oop(rbx);

   // VM needs caller's callsite

   // VM needs target method

   // This needs to be a long call since we will relocate this adapter to

   // the codeBuffer and it may not reach

   // Allocate argument register save area

   if (frame::arg_reg_save_area_bytes != 0) {

     __ subptr(rsp, frame::arg_reg_save_area_bytes);

   }

   __ mov(c_rarg0, rbx);

   __ mov(c_rarg1, rax);

   __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, SharedRuntime::fixup_callers_callsite)));

   // De-allocate argument register save area

   if (frame::arg_reg_save_area_bytes != 0) {

     __ addptr(rsp, frame::arg_reg_save_area_bytes);

   }

   __ pop_CPU_state();

   // restore sp

   __ mov(rsp, r13);

   __ bind(L);

 }

 static void gen_c2i_adapter(MacroAssembler *masm,

                             int total_args_passed,

                             int comp_args_on_stack,

                             const BasicType *sig_bt,

                             const VMRegPair *regs,

                             Label& skip_fixup) {

   // Before we get into the guts of the C2I adapter, see if we should be here

   // at all.  We've come from compiled code and are attempting to jump to the

   // interpreter, which means the caller made a static call to get here

   // (vcalls always get a compiled target if there is one).  Check for a

   // compiled target.  If there is one, we need to patch the caller's call.

   patch_callers_callsite(masm);

   __ bind(skip_fixup);

   // Since all args are passed on the stack, total_args_passed *

   // Interpreter::stackElementSize is the space we need. Plus 1 because

   // we also account for the return address location since

   // we store it first rather than hold it in rax across all the shuffling

   int extraspace = (total_args_passed * Interpreter::stackElementSize) + wordSize;

   // stack is aligned, keep it that way

   extraspace = round_to(extraspace, 2*wordSize);

   // Get return address

   __ pop(rax);

   // set senderSP value

   __ mov(r13, rsp);

   __ subptr(rsp, extraspace);

   // Store the return address in the expected location

   __ movptr(Address(rsp, 0), rax);

   // Now write the args into the outgoing interpreter space

   for (int i = 0; i < total_args_passed; i++) {

     if (sig_bt[i] == T_VOID) {

       assert(i > 0 && (sig_bt[i-1] == T_LONG || sig_bt[i-1] == T_DOUBLE), "missing half");

       continue;

     }

     // offset to start parameters

     int st_off   = (total_args_passed - i) * Interpreter::stackElementSize;

     int next_off = st_off - Interpreter::stackElementSize;

     // Say 4 args:

     // i   st_off

     // 0   32 T_LONG

     // 1   24 T_VOID

     // 2   16 T_OBJECT

     // 3    8 T_BOOL

     // -    0 return address

     //

     // However to make thing extra confusing. Because we can fit a long/double in

     // a single slot on a 64 bt vm and it would be silly to break them up, the interpreter

     // leaves one slot empty and only stores to a single slot. In this case the

     // slot that is occupied is the T_VOID slot. See I said it was confusing.

     VMReg r_1 = regs[i].first();

     VMReg r_2 = regs[i].second();

     if (!r_1->is_valid()) {

       assert(!r_2->is_valid(), "");

       continue;

     }

     if (r_1->is_stack()) {

       // memory to memory use rax

       int ld_off = r_1->reg2stack() * VMRegImpl::stack_slot_size + extraspace;

       if (!r_2->is_valid()) {

         // sign extend??

         __ movl(rax, Address(rsp, ld_off));

         __ movptr(Address(rsp, st_off), rax);

       } else {

         __ movq(rax, Address(rsp, ld_off));

         // Two VMREgs|OptoRegs can be T_OBJECT, T_ADDRESS, T_DOUBLE, T_LONG

         // T_DOUBLE and T_LONG use two slots in the interpreter

         if ( sig_bt[i] == T_LONG || sig_bt[i] == T_DOUBLE) {

           // ld_off == LSW, ld_off+wordSize == MSW

           // st_off == MSW, next_off == LSW

           __ movq(Address(rsp, next_off), rax);

 #ifdef ASSERT

           // Overwrite the unused slot with known junk

           __ mov64(rax, CONST64(0xdeadffffdeadaaaa));

           __ movptr(Address(rsp, st_off), rax);

 #endif /* ASSERT */

         } else {

           __ movq(Address(rsp, st_off), rax);

         }

       }

     } else if (r_1->is_Register()) {

       Register r = r_1->as_Register();

       if (!r_2->is_valid()) {

         // must be only an int (or less ) so move only 32bits to slot

         // why not sign extend??

         __ movl(Address(rsp, st_off), r);

       } else {

         // Two VMREgs|OptoRegs can be T_OBJECT, T_ADDRESS, T_DOUBLE, T_LONG

         // T_DOUBLE and T_LONG use two slots in the interpreter

         if ( sig_bt[i] == T_LONG || sig_bt[i] == T_DOUBLE) {

           // long/double in gpr

 #ifdef ASSERT

           // Overwrite the unused slot with known junk

           __ mov64(rax, CONST64(0xdeadffffdeadaaab));

           __ movptr(Address(rsp, st_off), rax);

 #endif /* ASSERT */

           __ movq(Address(rsp, next_off), r);

         } else {

           __ movptr(Address(rsp, st_off), r);

         }

       }

     } else {

       assert(r_1->is_XMMRegister(), "");

       if (!r_2->is_valid()) {

         // only a float use just part of the slot

         __ movflt(Address(rsp, st_off), r_1->as_XMMRegister());

       } else {

 #ifdef ASSERT

         // Overwrite the unused slot with known junk

         __ mov64(rax, CONST64(0xdeadffffdeadaaac));

         __ movptr(Address(rsp, st_off), rax);

 #endif /* ASSERT */

         __ movdbl(Address(rsp, next_off), r_1->as_XMMRegister());

       }

     }

   }

   // Schedule the branch target address early.

   __ movptr(rcx, Address(rbx, in_bytes(methodOopDesc::interpreter_entry_offset())));

   __ jmp(rcx);

 }

 static void gen_i2c_adapter(MacroAssembler *masm,

                             int total_args_passed,

                             int comp_args_on_stack,

                             const BasicType *sig_bt,

                             const VMRegPair *regs) {

   // Note: r13 contains the senderSP on entry. We must preserve it since

   // we may do a i2c -> c2i transition if we lose a race where compiled

   // code goes non-entrant while we get args ready.

   // In addition we use r13 to locate all the interpreter args as

   // we must align the stack to 16 bytes on an i2c entry else we

   // lose alignment we expect in all compiled code and register

   // save code can segv when fxsave instructions find improperly

   // aligned stack pointer.

   // Pick up the return address

   __ movptr(rax, Address(rsp, 0));

   // Must preserve original SP for loading incoming arguments because

   // we need to align the outgoing SP for compiled code.

   __ movptr(r11, rsp);

   // Cut-out for having no stack args.  Since up to 2 int/oop args are passed

   // in registers, we will occasionally have no stack args.

   int comp_words_on_stack = 0;

   if (comp_args_on_stack) {

     // Sig words on the stack are greater-than VMRegImpl::stack0.  Those in

     // registers are below.  By subtracting stack0, we either get a negative

     // number (all values in registers) or the maximum stack slot accessed.

     // Convert 4-byte c2 stack slots to words.

     comp_words_on_stack = round_to(comp_args_on_stack*VMRegImpl::stack_slot_size, wordSize)>>LogBytesPerWord;

     // Round up to miminum stack alignment, in wordSize

     comp_words_on_stack = round_to(comp_words_on_stack, 2);

     __ subptr(rsp, comp_words_on_stack * wordSize);

   }

   // Ensure compiled code always sees stack at proper alignment

   __ andptr(rsp, -16);

   // push the return address and misalign the stack that youngest frame always sees

   // as far as the placement of the call instruction

   __ push(rax);

   // Put saved SP in another register

   const Register saved_sp = rax;

   __ movptr(saved_sp, r11);

   // Will jump to the compiled code just as if compiled code was doing it.

   // Pre-load the register-jump target early, to schedule it better.

   __ movptr(r11, Address(rbx, in_bytes(methodOopDesc::from_compiled_offset())));

   // Now generate the shuffle code.  Pick up all register args and move the

   // rest through the floating point stack top.

   for (int i = 0; i < total_args_passed; i++) {

     if (sig_bt[i] == T_VOID) {

       // Longs and doubles are passed in native word order, but misaligned

       // in the 32-bit build.

       assert(i > 0 && (sig_bt[i-1] == T_LONG || sig_bt[i-1] == T_DOUBLE), "missing half");

       continue;

     }

     // Pick up 0, 1 or 2 words from SP+offset.

     assert(!regs[i].second()->is_valid() || regs[i].first()->next() == regs[i].second(),

             "scrambled load targets?");

     // Load in argument order going down.

     int ld_off = (total_args_passed - i)*Interpreter::stackElementSize;

     // Point to interpreter value (vs. tag)

     int next_off = ld_off - Interpreter::stackElementSize;

     //

     //

     //

     VMReg r_1 = regs[i].first();

     VMReg r_2 = regs[i].second();

     if (!r_1->is_valid()) {

       assert(!r_2->is_valid(), "");

       continue;

     }

     if (r_1->is_stack()) {

       // Convert stack slot to an SP offset (+ wordSize to account for return address )

       int st_off = regs[i].first()->reg2stack()*VMRegImpl::stack_slot_size + wordSize;

       // We can use r13 as a temp here because compiled code doesn't need r13 as an input

       // and if we end up going thru a c2i because of a miss a reasonable value of r13

       // will be generated.

       if (!r_2->is_valid()) {

         // sign extend???

         __ movl(r13, Address(saved_sp, ld_off));

         __ movptr(Address(rsp, st_off), r13);

       } else {

         //

         // We are using two optoregs. This can be either T_OBJECT, T_ADDRESS, T_LONG, or T_DOUBLE

         // the interpreter allocates two slots but only uses one for thr T_LONG or T_DOUBLE case

         // So we must adjust where to pick up the data to match the interpreter.

         //

         // Interpreter local[n] == MSW, local[n+1] == LSW however locals

         // are accessed as negative so LSW is at LOW address

         // ld_off is MSW so get LSW

         const int offset = (sig_bt[i]==T_LONG||sig_bt[i]==T_DOUBLE)?

                            next_off : ld_off;

         __ movq(r13, Address(saved_sp, offset));

         // st_off is LSW (i.e. reg.first())

         __ movq(Address(rsp, st_off), r13);

       }

     } else if (r_1->is_Register()) {  // Register argument

       Register r = r_1->as_Register();

       assert(r != rax, "must be different");

       if (r_2->is_valid()) {

         //

         // We are using two VMRegs. This can be either T_OBJECT, T_ADDRESS, T_LONG, or T_DOUBLE

         // the interpreter allocates two slots but only uses one for thr T_LONG or T_DOUBLE case

         // So we must adjust where to pick up the data to match the interpreter.

         const int offset = (sig_bt[i]==T_LONG||sig_bt[i]==T_DOUBLE)?

                            next_off : ld_off;

         // this can be a misaligned move

         __ movq(r, Address(saved_sp, offset));

       } else {

         // sign extend and use a full word?

         __ movl(r, Address(saved_sp, ld_off));

       }

     } else {

       if (!r_2->is_valid()) {

         __ movflt(r_1->as_XMMRegister(), Address(saved_sp, ld_off));

       } else {

         __ movdbl(r_1->as_XMMRegister(), Address(saved_sp, next_off));

       }

     }

   }

   // 6243940 We might end up in handle_wrong_method if

   // the callee is deoptimized as we race thru here. If that

   // happens we don't want to take a safepoint because the

   // caller frame will look interpreted and arguments are now

   // "compiled" so it is much better to make this transition

   // invisible to the stack walking code. Unfortunately if

   // we try and find the callee by normal means a safepoint

   // is possible. So we stash the desired callee in the thread

   // and the vm will find there should this case occur.

   __ movptr(Address(r15_thread, JavaThread::callee_target_offset()), rbx);

   // put methodOop where a c2i would expect should we end up there

   // only needed becaus eof c2 resolve stubs return methodOop as a result in

   // rax

   __ mov(rax, rbx);

   __ jmp(r11);

 }

 // ---------------------------------------------------------------

 AdapterHandlerEntry* SharedRuntime::generate_i2c2i_adapters(MacroAssembler *masm,

                                                             int total_args_passed,

                                                             int comp_args_on_stack,

                                                             const BasicType *sig_bt,

                                                             const VMRegPair *regs,

                                                             AdapterFingerPrint* fingerprint) {

   address i2c_entry = __ pc();

   gen_i2c_adapter(masm, total_args_passed, comp_args_on_stack, sig_bt, regs);

   // -------------------------------------------------------------------------

   // Generate a C2I adapter.  On entry we know rbx holds the methodOop during calls

   // to the interpreter.  The args start out packed in the compiled layout.  They

   // need to be unpacked into the interpreter layout.  This will almost always

   // require some stack space.  We grow the current (compiled) stack, then repack

   // the args.  We  finally end in a jump to the generic interpreter entry point.

   // On exit from the interpreter, the interpreter will restore our SP (lest the

   // compiled code, which relys solely on SP and not RBP, get sick).

   address c2i_unverified_entry = __ pc();

   Label skip_fixup;

   Label ok;

   Register holder = rax;

   Register receiver = j_rarg0;

   Register temp = rbx;

   {

     __ verify_oop(holder);

     __ load_klass(temp, receiver);

     __ verify_oop(temp);

     __ cmpptr(temp, Address(holder, compiledICHolderOopDesc::holder_klass_offset()));

     __ movptr(rbx, Address(holder, compiledICHolderOopDesc::holder_method_offset()));

     __ jcc(Assembler::equal, ok);

     __ jump(RuntimeAddress(SharedRuntime::get_ic_miss_stub()));

     __ bind(ok);

     // Method might have been compiled since the call site was patched to

     // interpreted if that is the case treat it as a miss so we can get

     // the call site corrected.

     __ cmpptr(Address(rbx, in_bytes(methodOopDesc::code_offset())), (int32_t)NULL_WORD);

     __ jcc(Assembler::equal, skip_fixup);

     __ jump(RuntimeAddress(SharedRuntime::get_ic_miss_stub()));

   }

   address c2i_entry = __ pc();

   gen_c2i_adapter(masm, total_args_passed, comp_args_on_stack, sig_bt, regs, skip_fixup);

   __ flush();

   return AdapterHandlerLibrary::new_entry(fingerprint, i2c_entry, c2i_entry, c2i_unverified_entry);

 }

 int SharedRuntime::c_calling_convention(const BasicType *sig_bt,

                                          VMRegPair *regs,

                                          int total_args_passed) {

 // We return the amount of VMRegImpl stack slots we need to reserve for all

 // the arguments NOT counting out_preserve_stack_slots.

 // NOTE: These arrays will have to change when c1 is ported

 #ifdef _WIN64

     static const Register INT_ArgReg[Argument::n_int_register_parameters_c] = {

       c_rarg0, c_rarg1, c_rarg2, c_rarg3

     };

     static const XMMRegister FP_ArgReg[Argument::n_float_register_parameters_c] = {

       c_farg0, c_farg1, c_farg2, c_farg3

     };

 #else

     static const Register INT_ArgReg[Argument::n_int_register_parameters_c] = {

       c_rarg0, c_rarg1, c_rarg2, c_rarg3, c_rarg4, c_rarg5

     };

     static const XMMRegister FP_ArgReg[Argument::n_float_register_parameters_c] = {

       c_farg0, c_farg1, c_farg2, c_farg3,

       c_farg4, c_farg5, c_farg6, c_farg7

     };

 #endif // _WIN64

     uint int_args = 0;

     uint fp_args = 0;

     uint stk_args = 0; // inc by 2 each time

     for (int i = 0; i < total_args_passed; i++) {

       switch (sig_bt[i]) {

       case T_BOOLEAN:

       case T_CHAR:

       case T_BYTE:

       case T_SHORT:

       case T_INT:

         if (int_args < Argument::n_int_register_parameters_c) {

           regs[i].set1(INT_ArgReg[int_args++]->as_VMReg());

 #ifdef _WIN64

           fp_args++;

           // Allocate slots for callee to stuff register args the stack.

           stk_args += 2;

 #endif

         } else {

           regs[i].set1(VMRegImpl::stack2reg(stk_args));

           stk_args += 2;

         }

         break;

       case T_LONG:

         assert(sig_bt[i + 1] == T_VOID, "expecting half");

         // fall through

       case T_OBJECT:

       case T_ARRAY:

       case T_ADDRESS:

         if (int_args < Argument::n_int_register_parameters_c) {

           regs[i].set2(INT_ArgReg[int_args++]->as_VMReg());

 #ifdef _WIN64

           fp_args++;

           stk_args += 2;

 #endif

         } else {

           regs[i].set2(VMRegImpl::stack2reg(stk_args));

           stk_args += 2;

         }

         break;

       case T_FLOAT:

         if (fp_args < Argument::n_float_register_parameters_c) {

           regs[i].set1(FP_ArgReg[fp_args++]->as_VMReg());

 #ifdef _WIN64

           int_args++;

           // Allocate slots for callee to stuff register args the stack.

           stk_args += 2;

 #endif

         } else {

           regs[i].set1(VMRegImpl::stack2reg(stk_args));

           stk_args += 2;

         }

         break;

       case T_DOUBLE:

         assert(sig_bt[i + 1] == T_VOID, "expecting half");

         if (fp_args < Argument::n_float_register_parameters_c) {

           regs[i].set2(FP_ArgReg[fp_args++]->as_VMReg());

 #ifdef _WIN64

           int_args++;

           // Allocate slots for callee to stuff register args the stack.

           stk_args += 2;

 #endif

         } else {

           regs[i].set2(VMRegImpl::stack2reg(stk_args));

           stk_args += 2;

         }

         break;

       case T_VOID: // Halves of longs and doubles

         assert(i != 0 && (sig_bt[i - 1] == T_LONG || sig_bt[i - 1] == T_DOUBLE), "expecting half");

         regs[i].set_bad();

         break;

       default:

         ShouldNotReachHere();

         break;

       }

     }

 #ifdef _WIN64

   // windows abi requires that we always allocate enough stack space

   // for 4 64bit registers to be stored down.

   if (stk_args < 8) {

     stk_args = 8;

   }

 #endif // _WIN64

   return stk_args;

 }

 // On 64 bit we will store integer like items to the stack as

 // 64 bits items (sparc abi) even though java would only store

 // 32bits for a parameter. On 32bit it will simply be 32 bits

 // So this routine will do 32->32 on 32bit and 32->64 on 64bit

 static void move32_64(MacroAssembler* masm, VMRegPair src, VMRegPair dst) {

   if (src.first()->is_stack()) {

     if (dst.first()->is_stack()) {

       // stack to stack

       __ movslq(rax, Address(rbp, reg2offset_in(src.first())));

       __ movq(Address(rsp, reg2offset_out(dst.first())), rax);

     } else {

       // stack to reg

       __ movslq(dst.first()->as_Register(), Address(rbp, reg2offset_in(src.first())));

     }

   } else if (dst.first()->is_stack()) {

     // reg to stack

     // Do we really have to sign extend???

     // __ movslq(src.first()->as_Register(), src.first()->as_Register());

     __ movq(Address(rsp, reg2offset_out(dst.first())), src.first()->as_Register());

   } else {

     // Do we really have to sign extend???

     // __ movslq(dst.first()->as_Register(), src.first()->as_Register());

     if (dst.first() != src.first()) {

       __ movq(dst.first()->as_Register(), src.first()->as_Register());

     }

   }

 }

 // An oop arg. Must pass a handle not the oop itself

 static void object_move(MacroAssembler* masm,

                         OopMap* map,

                         int oop_handle_offset,

                         int framesize_in_slots,

                         VMRegPair src,

                         VMRegPair dst,

                         bool is_receiver,

                         int* receiver_offset) {

   // must pass a handle. First figure out the location we use as a handle

   Register rHandle = dst.first()->is_stack() ? rax : dst.first()->as_Register();

   // See if oop is NULL if it is we need no handle

   if (src.first()->is_stack()) {

     // Oop is already on the stack as an argument

     int offset_in_older_frame = src.first()->reg2stack() + SharedRuntime::out_preserve_stack_slots();

     map->set_oop(VMRegImpl::stack2reg(offset_in_older_frame + framesize_in_slots));

     if (is_receiver) {

       *receiver_offset = (offset_in_older_frame + framesize_in_slots) * VMRegImpl::stack_slot_size;

     }

     __ cmpptr(Address(rbp, reg2offset_in(src.first())), (int32_t)NULL_WORD);

     __ lea(rHandle, Address(rbp, reg2offset_in(src.first())));

     // conditionally move a NULL

     __ cmovptr(Assembler::equal, rHandle, Address(rbp, reg2offset_in(src.first())));

   } else {

     // Oop is in an a register we must store it to the space we reserve

     // on the stack for oop_handles and pass a handle if oop is non-NULL

     const Register rOop = src.first()->as_Register();

     int oop_slot;

     if (rOop == j_rarg0)

       oop_slot = 0;

     else if (rOop == j_rarg1)

       oop_slot = 1;

     else if (rOop == j_rarg2)

       oop_slot = 2;

     else if (rOop == j_rarg3)

       oop_slot = 3;

     else if (rOop == j_rarg4)

       oop_slot = 4;

     else {

       assert(rOop == j_rarg5, "wrong register");

       oop_slot = 5;

     }

     oop_slot = oop_slot * VMRegImpl::slots_per_word + oop_handle_offset;

     int offset = oop_slot*VMRegImpl::stack_slot_size;

     map->set_oop(VMRegImpl::stack2reg(oop_slot));

     // Store oop in handle area, may be NULL

     __ movptr(Address(rsp, offset), rOop);

     if (is_receiver) {

       *receiver_offset = offset;

     }

     __ cmpptr(rOop, (int32_t)NULL_WORD);

     __ lea(rHandle, Address(rsp, offset));

     // conditionally move a NULL from the handle area where it was just stored

     __ cmovptr(Assembler::equal, rHandle, Address(rsp, offset));

   }

   // If arg is on the stack then place it otherwise it is already in correct reg.

   if (dst.first()->is_stack()) {

     __ movptr(Address(rsp, reg2offset_out(dst.first())), rHandle);

   }

 }

 // A float arg may have to do float reg int reg conversion

 static void float_move(MacroAssembler* masm, VMRegPair src, VMRegPair dst) {

   assert(!src.second()->is_valid() && !dst.second()->is_valid(), "bad float_move");

   // The calling conventions assures us that each VMregpair is either

   // all really one physical register or adjacent stack slots.

   // This greatly simplifies the cases here compared to sparc.

   if (src.first()->is_stack()) {

     if (dst.first()->is_stack()) {

       __ movl(rax, Address(rbp, reg2offset_in(src.first())));

       __ movptr(Address(rsp, reg2offset_out(dst.first())), rax);

     } else {

       // stack to reg

       assert(dst.first()->is_XMMRegister(), "only expect xmm registers as parameters");

       __ movflt(dst.first()->as_XMMRegister(), Address(rbp, reg2offset_in(src.first())));

     }

   } else if (dst.first()->is_stack()) {

     // reg to stack

     assert(src.first()->is_XMMRegister(), "only expect xmm registers as parameters");

     __ movflt(Address(rsp, reg2offset_out(dst.first())), src.first()->as_XMMRegister());

   } else {

     // reg to reg

     // In theory these overlap but the ordering is such that this is likely a nop

     if ( src.first() != dst.first()) {

       __ movdbl(dst.first()->as_XMMRegister(),  src.first()->as_XMMRegister());

     }

   }

 }

 // A long move

 static void long_move(MacroAssembler* masm, VMRegPair src, VMRegPair dst) {

   // The calling conventions assures us that each VMregpair is either

   // all really one physical register or adjacent stack slots.

   // This greatly simplifies the cases here compared to sparc.

   if (src.is_single_phys_reg() ) {

     if (dst.is_single_phys_reg()) {

       if (dst.first() != src.first()) {

         __ mov(dst.first()->as_Register(), src.first()->as_Register());

       }

     } else {

       assert(dst.is_single_reg(), "not a stack pair");

       __ movq(Address(rsp, reg2offset_out(dst.first())), src.first()->as_Register());

     }

   } else if (dst.is_single_phys_reg()) {

     assert(src.is_single_reg(),  "not a stack pair");

     __ movq(dst.first()->as_Register(), Address(rbp, reg2offset_out(src.first())));

   } else {

     assert(src.is_single_reg() && dst.is_single_reg(), "not stack pairs");

     __ movq(rax, Address(rbp, reg2offset_in(src.first())));

     __ movq(Address(rsp, reg2offset_out(dst.first())), rax);

   }

 }

 // A double move

 static void double_move(MacroAssembler* masm, VMRegPair src, VMRegPair dst) {

   // The calling conventions assures us that each VMregpair is either

   // all really one physical register or adjacent stack slots.

   // This greatly simplifies the cases here compared to sparc.

   if (src.is_single_phys_reg() ) {

     if (dst.is_single_phys_reg()) {

       // In theory these overlap but the ordering is such that this is likely a nop

       if ( src.first() != dst.first()) {

         __ movdbl(dst.first()->as_XMMRegister(), src.first()->as_XMMRegister());

       }

     } else {

       assert(dst.is_single_reg(), "not a stack pair");

       __ movdbl(Address(rsp, reg2offset_out(dst.first())), src.first()->as_XMMRegister());

     }

   } else if (dst.is_single_phys_reg()) {

     assert(src.is_single_reg(),  "not a stack pair");

     __ movdbl(dst.first()->as_XMMRegister(), Address(rbp, reg2offset_out(src.first())));

   } else {

     assert(src.is_single_reg() && dst.is_single_reg(), "not stack pairs");

     __ movq(rax, Address(rbp, reg2offset_in(src.first())));

     __ movq(Address(rsp, reg2offset_out(dst.first())), rax);

   }

 }

 void SharedRuntime::save_native_result(MacroAssembler *masm, BasicType ret_type, int frame_slots) {

   // We always ignore the frame_slots arg and just use the space just below frame pointer

   // which by this time is free to use

   switch (ret_type) {

   case T_FLOAT:

     __ movflt(Address(rbp, -wordSize), xmm0);

     break;

   case T_DOUBLE:

     __ movdbl(Address(rbp, -wordSize), xmm0);

     break;

   case T_VOID:  break;

   default: {

     __ movptr(Address(rbp, -wordSize), rax);

     }

   }

 }

 void SharedRuntime::restore_native_result(MacroAssembler *masm, BasicType ret_type, int frame_slots) {

   // We always ignore the frame_slots arg and just use the space just below frame pointer

   // which by this time is free to use

   switch (ret_type) {

   case T_FLOAT:

     __ movflt(xmm0, Address(rbp, -wordSize));

     break;

   case T_DOUBLE:

     __ movdbl(xmm0, Address(rbp, -wordSize));

     break;

   case T_VOID:  break;

   default: {

     __ movptr(rax, Address(rbp, -wordSize));

     }

   }

 }

 static void save_args(MacroAssembler *masm, int arg_count, int first_arg, VMRegPair *args) {

     for ( int i = first_arg ; i < arg_count ; i++ ) {

       if (args[i].first()->is_Register()) {

         __ push(args[i].first()->as_Register());

       } else if (args[i].first()->is_XMMRegister()) {

         __ subptr(rsp, 2*wordSize);

         __ movdbl(Address(rsp, 0), args[i].first()->as_XMMRegister());

       }

     }

 }

 static void restore_args(MacroAssembler *masm, int arg_count, int first_arg, VMRegPair *args) {

     for ( int i = arg_count - 1 ; i >= first_arg ; i-- ) {

       if (args[i].first()->is_Register()) {

         __ pop(args[i].first()->as_Register());

       } else if (args[i].first()->is_XMMRegister()) {

         __ movdbl(args[i].first()->as_XMMRegister(), Address(rsp, 0));

         __ addptr(rsp, 2*wordSize);

       }

     }

 }

 // ---------------------------------------------------------------------------

 // Generate a native wrapper for a given method.  The method takes arguments

 // in the Java compiled code convention, marshals them to the native

 // convention (handlizes oops, etc), transitions to native, makes the call,

 // returns to java state (possibly blocking), unhandlizes any result and

 // returns.

 nmethod *SharedRuntime::generate_native_wrapper(MacroAssembler *masm,

                                                 methodHandle method,

                                                 int compile_id,

                                                 int total_in_args,

                                                 int comp_args_on_stack,

                                                 BasicType *in_sig_bt,

                                                 VMRegPair *in_regs,

                                                 BasicType ret_type) {

   // Native nmethod wrappers never take possesion of the oop arguments.

   // So the caller will gc the arguments. The only thing we need an

   // oopMap for is if the call is static

   //

   // An OopMap for lock (and class if static)

   OopMapSet *oop_maps = new OopMapSet();

   intptr_t start = (intptr_t)__ pc();

   // We have received a description of where all the java arg are located

   // on entry to the wrapper. We need to convert these args to where

   // the jni function will expect them. To figure out where they go

   // we convert the java signature to a C signature by inserting

   // the hidden arguments as arg[0] and possibly arg[1] (static method)

   int total_c_args = total_in_args + 1;

   if (method->is_static()) {

     total_c_args++;

   }

   BasicType* out_sig_bt = NEW_RESOURCE_ARRAY(BasicType, total_c_args);

   VMRegPair* out_regs   = NEW_RESOURCE_ARRAY(VMRegPair,   total_c_args);

   int argc = 0;

   out_sig_bt[argc++] = T_ADDRESS;

   if (method->is_static()) {

     out_sig_bt[argc++] = T_OBJECT;

   }

   for (int i = 0; i < total_in_args ; i++ ) {

     out_sig_bt[argc++] = in_sig_bt[i];

   }

   // Now figure out where the args must be stored and how much stack space

   // they require.

   //

   int out_arg_slots;

   out_arg_slots = c_calling_convention(out_sig_bt, out_regs, total_c_args);

   // Compute framesize for the wrapper.  We need to handlize all oops in

   // incoming registers

   // Calculate the total number of stack slots we will need.

   // First count the abi requirement plus all of the outgoing args

   int stack_slots = SharedRuntime::out_preserve_stack_slots() + out_arg_slots;

   // Now the space for the inbound oop handle area

   int oop_handle_offset = stack_slots;

   stack_slots += 6*VMRegImpl::slots_per_word;

   // Now any space we need for handlizing a klass if static method

   int oop_temp_slot_offset = 0;

   int klass_slot_offset = 0;

   int klass_offset = -1;

   int lock_slot_offset = 0;

   bool is_static = false;

   if (method->is_static()) {

     klass_slot_offset = stack_slots;

     stack_slots += VMRegImpl::slots_per_word;

     klass_offset = klass_slot_offset * VMRegImpl::stack_slot_size;

     is_static = true;

   }

   // Plus a lock if needed

   if (method->is_synchronized()) {

     lock_slot_offset = stack_slots;

     stack_slots += VMRegImpl::slots_per_word;

   }

   // Now a place (+2) to save return values or temp during shuffling

   // + 4 for return address (which we own) and saved rbp

   stack_slots += 6;

   // Ok The space we have allocated will look like:

   //

   //

   // FP-> |                     |

   //      |---------------------|

   //      | 2 slots for moves   |

   //      |---------------------|

   //      | lock box (if sync)  |

   //      |---------------------| <- lock_slot_offset

   //      | klass (if static)   |

   //      |---------------------| <- klass_slot_offset

   //      | oopHandle area      |

   //      |---------------------| <- oop_handle_offset (6 java arg registers)

   //      | outbound memory     |

   //      | based arguments     |

   //      |                     |

   //      |---------------------|

   //      |                     |

   // SP-> | out_preserved_slots |

   //

   //

   // Now compute actual number of stack words we need rounding to make

   // stack properly aligned.

   stack_slots = round_to(stack_slots, StackAlignmentInSlots);

   int stack_size = stack_slots * VMRegImpl::stack_slot_size;

   // First thing make an ic check to see if we should even be here

   // We are free to use all registers as temps without saving them and

   // restoring them except rbp. rbp is the only callee save register

   // as far as the interpreter and the compiler(s) are concerned.

   const Register ic_reg = rax;

   const Register receiver = j_rarg0;

   Label ok;

   Label exception_pending;

   assert_different_registers(ic_reg, receiver, rscratch1);

   __ verify_oop(receiver);

   __ load_klass(rscratch1, receiver);

   __ cmpq(ic_reg, rscratch1);

   __ jcc(Assembler::equal, ok);

   __ jump(RuntimeAddress(SharedRuntime::get_ic_miss_stub()));

   __ bind(ok);

   // Verified entry point must be aligned

   __ align(8);

   int vep_offset = ((intptr_t)__ pc()) - start;

   // The instruction at the verified entry point must be 5 bytes or longer

   // because it can be patched on the fly by make_non_entrant. The stack bang

   // instruction fits that requirement.

   // Generate stack overflow check

   if (UseStackBanging) {

     __ bang_stack_with_offset(StackShadowPages*os::vm_page_size());

   } else {

     // need a 5 byte instruction to allow MT safe patching to non-entrant

     __ fat_nop();

   }

   // Generate a new frame for the wrapper.

   __ enter();

   // -2 because return address is already present and so is saved rbp

   __ subptr(rsp, stack_size - 2*wordSize);

     // Frame is now completed as far as size and linkage.

     int frame_complete = ((intptr_t)__ pc()) - start;

 #ifdef ASSERT

     {

       Label L;

       __ mov(rax, rsp);

       __ andptr(rax, -16); // must be 16 byte boundary (see amd64 ABI)

       __ cmpptr(rax, rsp);

       __ jcc(Assembler::equal, L);

       __ stop("improperly aligned stack");

       __ bind(L);

     }

 #endif /* ASSERT */

   // We use r14 as the oop handle for the receiver/klass

   // It is callee save so it survives the call to native

   const Register oop_handle_reg = r14;

   //

   // We immediately shuffle the arguments so that any vm call we have to

   // make from here on out (sync slow path, jvmti, etc.) we will have

   // captured the oops from our caller and have a valid oopMap for

   // them.

   // -----------------

   // The Grand Shuffle

   // The Java calling convention is either equal (linux) or denser (win64) than the

   // c calling convention. However the because of the jni_env argument the c calling

   // convention always has at least one more (and two for static) arguments than Java.

   // Therefore if we move the args from java -> c backwards then we will never have

   // a register->register conflict and we don't have to build a dependency graph

   // and figure out how to break any cycles.

   //

   // Record esp-based slot for receiver on stack for non-static methods

   int receiver_offset = -1;

   // This is a trick. We double the stack slots so we can claim

   // the oops in the caller's frame. Since we are sure to have

   // more args than the caller doubling is enough to make

   // sure we can capture all the incoming oop args from the

   // caller.

   //

   OopMap* map = new OopMap(stack_slots * 2, 0 /* arg_slots*/);

   // Mark location of rbp (someday)

   // map->set_callee_saved(VMRegImpl::stack2reg( stack_slots - 2), stack_slots * 2, 0, vmreg(rbp));

   // Use eax, ebx as temporaries during any memory-memory moves we have to do

   // All inbound args are referenced based on rbp and all outbound args via rsp.

 #ifdef ASSERT

   bool reg_destroyed[RegisterImpl::number_of_registers];

   bool freg_destroyed[XMMRegisterImpl::number_of_registers];

   for ( int r = 0 ; r < RegisterImpl::number_of_registers ; r++ ) {

     reg_destroyed[r] = false;

   }

   for ( int f = 0 ; f < XMMRegisterImpl::number_of_registers ; f++ ) {

     freg_destroyed[f] = false;

   }

 #endif /* ASSERT */

   int c_arg = total_c_args - 1;

   for ( int i = total_in_args - 1; i >= 0 ; i--, c_arg-- ) {

 #ifdef ASSERT

     if (in_regs[i].first()->is_Register()) {

       assert(!reg_destroyed[in_regs[i].first()->as_Register()->encoding()], "destroyed reg!");

     } else if (in_regs[i].first()->is_XMMRegister()) {

       assert(!freg_destroyed[in_regs[i].first()->as_XMMRegister()->encoding()], "destroyed reg!");

     }

     if (out_regs[c_arg].first()->is_Register()) {

       reg_destroyed[out_regs[c_arg].first()->as_Register()->encoding()] = true;

     } else if (out_regs[c_arg].first()->is_XMMRegister()) {

       freg_destroyed[out_regs[c_arg].first()->as_XMMRegister()->encoding()] = true;

     }

 #endif /* ASSERT */

     switch (in_sig_bt[i]) {

       case T_ARRAY:

       case T_OBJECT:

         object_move(masm, map, oop_handle_offset, stack_slots, in_regs[i], out_regs[c_arg],

                     ((i == 0) && (!is_static)),

                     &receiver_offset);

         break;

       case T_VOID:

         break;

       case T_FLOAT:

         float_move(masm, in_regs[i], out_regs[c_arg]);

           break;

       case T_DOUBLE:

         assert( i + 1 < total_in_args &&

                 in_sig_bt[i + 1] == T_VOID &&

                 out_sig_bt[c_arg+1] == T_VOID, "bad arg list");

         double_move(masm, in_regs[i], out_regs[c_arg]);

         break;

       case T_LONG :

         long_move(masm, in_regs[i], out_regs[c_arg]);

         break;

       case T_ADDRESS: assert(false, "found T_ADDRESS in java args");

       default:

         move32_64(masm, in_regs[i], out_regs[c_arg]);

     }

   }

   // point c_arg at the first arg that is already loaded in case we

   // need to spill before we call out

   c_arg++;

   // Pre-load a static method's oop into r14.  Used both by locking code and

   // the normal JNI call code.

   if (method->is_static()) {

     //  load oop into a register

     __ movoop(oop_handle_reg, JNIHandles::make_local(Klass::cast(method->method_holder())->java_mirror()));

     // Now handlize the static class mirror it's known not-null.

     __ movptr(Address(rsp, klass_offset), oop_handle_reg);

     map->set_oop(VMRegImpl::stack2reg(klass_slot_offset));

     // Now get the handle

     __ lea(oop_handle_reg, Address(rsp, klass_offset));

     // store the klass handle as second argument

     __ movptr(c_rarg1, oop_handle_reg);

     // and protect the arg if we must spill

     c_arg--;

   }

   // Change state to native (we save the return address in the thread, since it might not

   // be pushed on the stack when we do a a stack traversal). It is enough that the pc()

   // points into the right code segment. It does not have to be the correct return pc.

   // We use the same pc/oopMap repeatedly when we call out

   intptr_t the_pc = (intptr_t) __ pc();

   oop_maps->add_gc_map(the_pc - start, map);

   __ set_last_Java_frame(rsp, noreg, (address)the_pc);

   // We have all of the arguments setup at this point. We must not touch any register

   // argument registers at this point (what if we save/restore them there are no oop?

   {

     SkipIfEqual skip(masm, &DTraceMethodProbes, false);

     // protect the args we've loaded

     save_args(masm, total_c_args, c_arg, out_regs);

     __ movoop(c_rarg1, JNIHandles::make_local(method()));

     __ call_VM_leaf(

       CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_entry),

       r15_thread, c_rarg1);

     restore_args(masm, total_c_args, c_arg, out_regs);

   }

   // RedefineClasses() tracing support for obsolete method entry

   if (RC_TRACE_IN_RANGE(0x00001000, 0x00002000)) {

     // protect the args we've loaded

     save_args(masm, total_c_args, c_arg, out_regs);

     __ movoop(c_rarg1, JNIHandles::make_local(method()));

     __ call_VM_leaf(

       CAST_FROM_FN_PTR(address, SharedRuntime::rc_trace_method_entry),

       r15_thread, c_rarg1);

     restore_args(masm, total_c_args, c_arg, out_regs);

   }

   // Lock a synchronized method

   // Register definitions used by locking and unlocking

   const Register swap_reg = rax;  // Must use rax for cmpxchg instruction

   const Register obj_reg  = rbx;  // Will contain the oop

   const Register lock_reg = r13;  // Address of compiler lock object (BasicLock)

   const Register old_hdr  = r13;  // value of old header at unlock time

   Label slow_path_lock;

   Label lock_done;

   if (method->is_synchronized()) {

     const int mark_word_offset = BasicLock::displaced_header_offset_in_bytes();

     // Get the handle (the 2nd argument)

     __ mov(oop_handle_reg, c_rarg1);

     // Get address of the box

     __ lea(lock_reg, Address(rsp, lock_slot_offset * VMRegImpl::stack_slot_size));

     // Load the oop from the handle

     __ movptr(obj_reg, Address(oop_handle_reg, 0));

     if (UseBiasedLocking) {

       __ biased_locking_enter(lock_reg, obj_reg, swap_reg, rscratch1, false, lock_done, &slow_path_lock);

     }

     // Load immediate 1 into swap_reg %rax

     __ movl(swap_reg, 1);

     // Load (object->mark() | 1) into swap_reg %rax

     __ orptr(swap_reg, Address(obj_reg, 0));

     // Save (object->mark() | 1) into BasicLock's displaced header

     __ movptr(Address(lock_reg, mark_word_offset), swap_reg);

     if (os::is_MP()) {

       __ lock();

     }

     // src -> dest iff dest == rax else rax <- dest

     __ cmpxchgptr(lock_reg, Address(obj_reg, 0));

     __ jcc(Assembler::equal, lock_done);

     // Hmm should this move to the slow path code area???

     // Test if the oopMark is an obvious stack pointer, i.e.,

     //  1) (mark & 3) == 0, and

     //  2) rsp <= mark < mark + os::pagesize()

     // These 3 tests can be done by evaluating the following

     // expression: ((mark - rsp) & (3 - os::vm_page_size())),

     // assuming both stack pointer and pagesize have their

     // least significant 2 bits clear.

     // NOTE: the oopMark is in swap_reg %rax as the result of cmpxchg

     __ subptr(swap_reg, rsp);

     __ andptr(swap_reg, 3 - os::vm_page_size());

     // Save the test result, for recursive case, the result is zero

     __ movptr(Address(lock_reg, mark_word_offset), swap_reg);

     __ jcc(Assembler::notEqual, slow_path_lock);

     // Slow path will re-enter here

     __ bind(lock_done);

   }

   // Finally just about ready to make the JNI call

   // get JNIEnv* which is first argument to native

   __ lea(c_rarg0, Address(r15_thread, in_bytes(JavaThread::jni_environment_offset())));

   // Now set thread in native

   __ movl(Address(r15_thread, JavaThread::thread_state_offset()), _thread_in_native);

   __ call(RuntimeAddress(method->native_function()));

     // Either restore the MXCSR register after returning from the JNI Call

     // or verify that it wasn't changed.

     if (RestoreMXCSROnJNICalls) {

       __ ldmxcsr(ExternalAddress(StubRoutines::x86::mxcsr_std()));

     }

     else if (CheckJNICalls ) {

       __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, StubRoutines::x86::verify_mxcsr_entry())));

     }

   // Unpack native results.

   switch (ret_type) {

   case T_BOOLEAN: __ c2bool(rax);            break;

   case T_CHAR   : __ movzwl(rax, rax);      break;

   case T_BYTE   : __ sign_extend_byte (rax); break;

   case T_SHORT  : __ sign_extend_short(rax); break;

   case T_INT    : /* nothing to do */        break;

   case T_DOUBLE :

   case T_FLOAT  :

     // Result is in xmm0 we'll save as needed

     break;

   case T_ARRAY:                 // Really a handle

   case T_OBJECT:                // Really a handle

       break; // can't de-handlize until after safepoint check

   case T_VOID: break;

   case T_LONG: break;

   default       : ShouldNotReachHere();

   }

   // Switch thread to "native transition" state before reading the synchronization state.

   // This additional state is necessary because reading and testing the synchronization

   // state is not atomic w.r.t. GC, as this scenario demonstrates:

   //     Java thread A, in _thread_in_native state, loads _not_synchronized and is preempted.

   //     VM thread changes sync state to synchronizing and suspends threads for GC.

   //     Thread A is resumed to finish this native method, but doesn't block here since it

   //     didn't see any synchronization is progress, and escapes.

   __ movl(Address(r15_thread, JavaThread::thread_state_offset()), _thread_in_native_trans);

   if(os::is_MP()) {

     if (UseMembar) {

       // Force this write out before the read below

       __ membar(Assembler::Membar_mask_bits(

            Assembler::LoadLoad | Assembler::LoadStore |

            Assembler::StoreLoad | Assembler::StoreStore));

     } else {

       // Write serialization page so VM thread can do a pseudo remote membar.

       // We use the current thread pointer to calculate a thread specific

       // offset to write to within the page. This minimizes bus traffic

       // due to cache line collision.

       __ serialize_memory(r15_thread, rcx);

     }

   }

   // check for safepoint operation in progress and/or pending suspend requests

   {

     Label Continue;

     __ cmp32(ExternalAddress((address)SafepointSynchronize::address_of_state()),

              SafepointSynchronize::_not_synchronized);

     Label L;

     __ jcc(Assembler::notEqual, L);

     __ cmpl(Address(r15_thread, JavaThread::suspend_flags_offset()), 0);

     __ jcc(Assembler::equal, Continue);

     __ bind(L);

     // Don't use call_VM as it will see a possible pending exception and forward it

     // and never return here preventing us from clearing _last_native_pc down below.

     // Also can't use call_VM_leaf either as it will check to see if rsi & rdi are

     // preserved and correspond to the bcp/locals pointers. So we do a runtime call

     // by hand.

     //

     save_native_result(masm, ret_type, stack_slots);

     __ mov(c_rarg0, r15_thread);

     __ mov(r12, rsp); // remember sp

     __ subptr(rsp, frame::arg_reg_save_area_bytes); // windows

     __ andptr(rsp, -16); // align stack as required by ABI

     __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, JavaThread::check_special_condition_for_native_trans)));

     __ mov(rsp, r12); // restore sp

     __ reinit_heapbase();

     // Restore any method result value

     restore_native_result(masm, ret_type, stack_slots);

     __ bind(Continue);

   }

   // change thread state

   __ movl(Address(r15_thread, JavaThread::thread_state_offset()), _thread_in_Java);

   Label reguard;

   Label reguard_done;

   __ cmpl(Address(r15_thread, JavaThread::stack_guard_state_offset()), JavaThread::stack_guard_yellow_disabled);

   __ jcc(Assembler::equal, reguard);

   __ bind(reguard_done);

   // native result if any is live

   // Unlock

   Label unlock_done;

   Label slow_path_unlock;

   if (method->is_synchronized()) {

     // Get locked oop from the handle we passed to jni

     __ movptr(obj_reg, Address(oop_handle_reg, 0));

     Label done;

     if (UseBiasedLocking) {

       __ biased_locking_exit(obj_reg, old_hdr, done);

     }

     // Simple recursive lock?

     __ cmpptr(Address(rsp, lock_slot_offset * VMRegImpl::stack_slot_size), (int32_t)NULL_WORD);

     __ jcc(Assembler::equal, done);

     // Must save rax if if it is live now because cmpxchg must use it

     if (ret_type != T_FLOAT && ret_type != T_DOUBLE && ret_type != T_VOID) {

       save_native_result(masm, ret_type, stack_slots);

     }

     // get address of the stack lock

     __ lea(rax, Address(rsp, lock_slot_offset * VMRegImpl::stack_slot_size));

     //  get old displaced header

     __ movptr(old_hdr, Address(rax, 0));

     // Atomic swap old header if oop still contains the stack lock

     if (os::is_MP()) {

       __ lock();

     }

     __ cmpxchgptr(old_hdr, Address(obj_reg, 0));

     __ jcc(Assembler::notEqual, slow_path_unlock);

     // slow path re-enters here

     __ bind(unlock_done);

     if (ret_type != T_FLOAT && ret_type != T_DOUBLE && ret_type != T_VOID) {

       restore_native_result(masm, ret_type, stack_slots);

     }

     __ bind(done);

   }

   {

     SkipIfEqual skip(masm, &DTraceMethodProbes, false);

     save_native_result(masm, ret_type, stack_slots);

     __ movoop(c_rarg1, JNIHandles::make_local(method()));

     __ call_VM_leaf(

          CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_exit),

          r15_thread, c_rarg1);

     restore_native_result(masm, ret_type, stack_slots);

   }

   __ reset_last_Java_frame(false, true);

   // Unpack oop result

   if (ret_type == T_OBJECT || ret_type == T_ARRAY) {

       Label L;

       __ testptr(rax, rax);

       __ jcc(Assembler::zero, L);

       __ movptr(rax, Address(rax, 0));

       __ bind(L);

       __ verify_oop(rax);

   }

   // reset handle block

   __ movptr(rcx, Address(r15_thread, JavaThread::active_handles_offset()));

   __ movptr(Address(rcx, JNIHandleBlock::top_offset_in_bytes()), (int32_t)NULL_WORD);

   // pop our frame

   __ leave();

   // Any exception pending?

   __ cmpptr(Address(r15_thread, in_bytes(Thread::pending_exception_offset())), (int32_t)NULL_WORD);

   __ jcc(Assembler::notEqual, exception_pending);

   // Return

   __ ret(0);

   // Unexpected paths are out of line and go here

   // forward the exception

   __ bind(exception_pending);

   // and forward the exception

   __ jump(RuntimeAddress(StubRoutines::forward_exception_entry()));

   // Slow path locking & unlocking

   if (method->is_synchronized()) {

     // BEGIN Slow path lock

     __ bind(slow_path_lock);

     // has last_Java_frame setup. No exceptions so do vanilla call not call_VM

     // args are (oop obj, BasicLock* lock, JavaThread* thread)

     // protect the args we've loaded

     save_args(masm, total_c_args, c_arg, out_regs);

     __ mov(c_rarg0, obj_reg);

     __ mov(c_rarg1, lock_reg);

     __ mov(c_rarg2, r15_thread);

     // Not a leaf but we have last_Java_frame setup as we want

     __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_locking_C), 3);

     restore_args(masm, total_c_args, c_arg, out_regs);

 #ifdef ASSERT

     { Label L;

     __ cmpptr(Address(r15_thread, in_bytes(Thread::pending_exception_offset())), (int32_t)NULL_WORD);

     __ jcc(Assembler::equal, L);

     __ stop("no pending exception allowed on exit from monitorenter");

     __ bind(L);

     }

 #endif

     __ jmp(lock_done);

     // END Slow path lock

     // BEGIN Slow path unlock

     __ bind(slow_path_unlock);

     // If we haven't already saved the native result we must save it now as xmm registers

     // are still exposed.

     if (ret_type == T_FLOAT || ret_type == T_DOUBLE ) {

       save_native_result(masm, ret_type, stack_slots);

     }

     __ lea(c_rarg1, Address(rsp, lock_slot_offset * VMRegImpl::stack_slot_size));

     __ mov(c_rarg0, obj_reg);

     __ mov(r12, rsp); // remember sp

     __ subptr(rsp, frame::arg_reg_save_area_bytes); // windows

     __ andptr(rsp, -16); // align stack as required by ABI

     // Save pending exception around call to VM (which contains an EXCEPTION_MARK)

     // NOTE that obj_reg == rbx currently

     __ movptr(rbx, Address(r15_thread, in_bytes(Thread::pending_exception_offset())));

     __ movptr(Address(r15_thread, in_bytes(Thread::pending_exception_offset())), (int32_t)NULL_WORD);

     __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_unlocking_C)));

     __ mov(rsp, r12); // restore sp

     __ reinit_heapbase();

 #ifdef ASSERT

     {

       Label L;

       __ cmpptr(Address(r15_thread, in_bytes(Thread::pending_exception_offset())), (int)NULL_WORD);

       __ jcc(Assembler::equal, L);

       __ stop("no pending exception allowed on exit complete_monitor_unlocking_C");

       __ bind(L);

     }

 #endif /* ASSERT */

     __ movptr(Address(r15_thread, in_bytes(Thread::pending_exception_offset())), rbx);

     if (ret_type == T_FLOAT || ret_type == T_DOUBLE ) {

       restore_native_result(masm, ret_type, stack_slots);

     }

     __ jmp(unlock_done);

     // END Slow path unlock

   } // synchronized

   // SLOW PATH Reguard the stack if needed

   __ bind(reguard);

   save_native_result(masm, ret_type, stack_slots);

   __ mov(r12, rsp); // remember sp

   __ subptr(rsp, frame::arg_reg_save_area_bytes); // windows

   __ andptr(rsp, -16); // align stack as required by ABI

   __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, SharedRuntime::reguard_yellow_pages)));

   __ mov(rsp, r12); // restore sp

   __ reinit_heapbase();

   restore_native_result(masm, ret_type, stack_slots);

   // and continue

   __ jmp(reguard_done);

   __ flush();

   nmethod *nm = nmethod::new_native_nmethod(method,

                                             compile_id,

                                             masm->code(),

                                             vep_offset,

                                             frame_complete,

                                             stack_slots / VMRegImpl::slots_per_word,

                                             (is_static ? in_ByteSize(klass_offset) : in_ByteSize(receiver_offset)),

                                             in_ByteSize(lock_slot_offset*VMRegImpl::stack_slot_size),

                                             oop_maps);

   return nm;

 }

 #ifdef HAVE_DTRACE_H

 // ---------------------------------------------------------------------------

 // Generate a dtrace nmethod for a given signature.  The method takes arguments

 // in the Java compiled code convention, marshals them to the native

 // abi and then leaves nops at the position you would expect to call a native

 // function. When the probe is enabled the nops are replaced with a trap

 // instruction that dtrace inserts and the trace will cause a notification

 // to dtrace.

 //

 // The probes are only able to take primitive types and java/lang/String as

 // arguments.  No other java types are allowed. Strings are converted to utf8

 // strings so that from dtrace point of view java strings are converted to C

 // strings. There is an arbitrary fixed limit on the total space that a method

 // can use for converting the strings. (256 chars per string in the signature).

 // So any java string larger then this is truncated.

 static int  fp_offset[ConcreteRegisterImpl::number_of_registers] = { 0 };

 static bool offsets_initialized = false;

 nmethod *SharedRuntime::generate_dtrace_nmethod(MacroAssembler *masm,

                                                 methodHandle method) {

   // generate_dtrace_nmethod is guarded by a mutex so we are sure to

   // be single threaded in this method.

   assert(AdapterHandlerLibrary_lock->owned_by_self(), "must be");

   if (!offsets_initialized) {

     fp_offset[c_rarg0->as_VMReg()->value()] = -1 * wordSize;

     fp_offset[c_rarg1->as_VMReg()->value()] = -2 * wordSize;

     fp_offset[c_rarg2->as_VMReg()->value()] = -3 * wordSize;

     fp_offset[c_rarg3->as_VMReg()->value()] = -4 * wordSize;

     fp_offset[c_rarg4->as_VMReg()->value()] = -5 * wordSize;

     fp_offset[c_rarg5->as_VMReg()->value()] = -6 * wordSize;

     fp_offset[c_farg0->as_VMReg()->value()] = -7 * wordSize;

     fp_offset[c_farg1->as_VMReg()->value()] = -8 * wordSize;

     fp_offset[c_farg2->as_VMReg()->value()] = -9 * wordSize;

     fp_offset[c_farg3->as_VMReg()->value()] = -10 * wordSize;

     fp_offset[c_farg4->as_VMReg()->value()] = -11 * wordSize;

     fp_offset[c_farg5->as_VMReg()->value()] = -12 * wordSize;

     fp_offset[c_farg6->as_VMReg()->value()] = -13 * wordSize;

     fp_offset[c_farg7->as_VMReg()->value()] = -14 * wordSize;

     offsets_initialized = true;

   }

   // Fill in the signature array, for the calling-convention call.

   int total_args_passed = method->size_of_parameters();

   BasicType* in_sig_bt  = NEW_RESOURCE_ARRAY(BasicType, total_args_passed);

   VMRegPair  *in_regs   = NEW_RESOURCE_ARRAY(VMRegPair, total_args_passed);

   // The signature we are going to use for the trap that dtrace will see

   // java/lang/String is converted. We drop "this" and any other object

   // is converted to NULL.  (A one-slot java/lang/Long object reference

   // is converted to a two-slot long, which is why we double the allocation).

   BasicType* out_sig_bt = NEW_RESOURCE_ARRAY(BasicType, total_args_passed * 2);

   VMRegPair* out_regs   = NEW_RESOURCE_ARRAY(VMRegPair, total_args_passed * 2);

   int i=0;

   int total_strings = 0;

   int first_arg_to_pass = 0;

   int total_c_args = 0;

   // Skip the receiver as dtrace doesn't want to see it

   if( !method->is_static() ) {

     in_sig_bt[i++] = T_OBJECT;

     first_arg_to_pass = 1;

   }

   // We need to convert the java args to where a native (non-jni) function

   // would expect them. To figure out where they go we convert the java

   // signature to a C signature.

   SignatureStream ss(method->signature());

   for ( ; !ss.at_return_type(); ss.next()) {

     BasicType bt = ss.type();

     in_sig_bt[i++] = bt;  // Collect remaining bits of signature

     out_sig_bt[total_c_args++] = bt;

     if( bt == T_OBJECT) {

       Symbol* s = ss.as_symbol_or_null();   // symbol is created

       if (s == vmSymbols::java_lang_String()) {

         total_strings++;

         out_sig_bt[total_c_args-1] = T_ADDRESS;

       } else if (s == vmSymbols::java_lang_Boolean() ||

                  s == vmSymbols::java_lang_Character() ||

                  s == vmSymbols::java_lang_Byte() ||

                  s == vmSymbols::java_lang_Short() ||

                  s == vmSymbols::java_lang_Integer() ||

                  s == vmSymbols::java_lang_Float()) {

         out_sig_bt[total_c_args-1] = T_INT;

       } else if (s == vmSymbols::java_lang_Long() ||

                  s == vmSymbols::java_lang_Double()) {

         out_sig_bt[total_c_args-1] = T_LONG;

         out_sig_bt[total_c_args++] = T_VOID;

       }

     } else if ( bt == T_LONG || bt == T_DOUBLE ) {

       in_sig_bt[i++] = T_VOID;   // Longs & doubles take 2 Java slots

       // We convert double to long

       out_sig_bt[total_c_args-1] = T_LONG;

       out_sig_bt[total_c_args++] = T_VOID;

     } else if ( bt == T_FLOAT) {

       // We convert float to int

       out_sig_bt[total_c_args-1] = T_INT;

     }

   }

   assert(i==total_args_passed, "validly parsed signature");

   // Now get the compiled-Java layout as input arguments

   int comp_args_on_stack;

   comp_args_on_stack = SharedRuntime::java_calling_convention(

       in_sig_bt, in_regs, total_args_passed, false);

   // Now figure out where the args must be stored and how much stack space

   // they require (neglecting out_preserve_stack_slots but space for storing

   // the 1st six register arguments). It's weird see int_stk_helper.

   int out_arg_slots;

   out_arg_slots = c_calling_convention(out_sig_bt, out_regs, total_c_args);

   // Calculate the total number of stack slots we will need.

   // First count the abi requirement plus all of the outgoing args

   int stack_slots = SharedRuntime::out_preserve_stack_slots() + out_arg_slots;

   // Now space for the string(s) we must convert

   int* string_locs   = NEW_RESOURCE_ARRAY(int, total_strings + 1);

   for (i = 0; i < total_strings ; i++) {

     string_locs[i] = stack_slots;

     stack_slots += max_dtrace_string_size / VMRegImpl::stack_slot_size;

   }

   // Plus the temps we might need to juggle register args

   // regs take two slots each

   stack_slots += (Argument::n_int_register_parameters_c +

                   Argument::n_float_register_parameters_c) * 2;

   // + 4 for return address (which we own) and saved rbp,

   stack_slots += 4;

   // Ok The space we have allocated will look like:

   //

   //

   // FP-> |                     |

   //      |---------------------|

   //      | string[n]           |

   //      |---------------------| <- string_locs[n]

   //      | string[n-1]         |

   //      |---------------------| <- string_locs[n-1]

   //      | ...                 |

   //      | ...                 |

   //      |---------------------| <- string_locs[1]

   //      | string[0]           |

   //      |---------------------| <- string_locs[0]

   //      | outbound memory     |

   //      | based arguments     |

   //      |                     |

   //      |---------------------|

   //      |                     |

   // SP-> | out_preserved_slots |

   //

   //

   // Now compute actual number of stack words we need rounding to make

   // stack properly aligned.

   stack_slots = round_to(stack_slots, 4 * VMRegImpl::slots_per_word);

   int stack_size = stack_slots * VMRegImpl::stack_slot_size;

   intptr_t start = (intptr_t)__ pc();

   // First thing make an ic check to see if we should even be here

   // We are free to use all registers as temps without saving them and

   // restoring them except rbp. rbp, is the only callee save register

   // as far as the interpreter and the compiler(s) are concerned.

   const Register ic_reg = rax;

   const Register receiver = rcx;

   Label hit;

   Label exception_pending;

   __ verify_oop(receiver);

   __ cmpl(ic_reg, Address(receiver, oopDesc::klass_offset_in_bytes()));

   __ jcc(Assembler::equal, hit);

   __ jump(RuntimeAddress(SharedRuntime::get_ic_miss_stub()));

   // verified entry must be aligned for code patching.

   // and the first 5 bytes must be in the same cache line

   // if we align at 8 then we will be sure 5 bytes are in the same line

   __ align(8);

   __ bind(hit);

   int vep_offset = ((intptr_t)__ pc()) - start;

   // The instruction at the verified entry point must be 5 bytes or longer

   // because it can be patched on the fly by make_non_entrant. The stack bang

   // instruction fits that requirement.

   // Generate stack overflow check

   if (UseStackBanging) {

     if (stack_size <= StackShadowPages*os::vm_page_size()) {

       __ bang_stack_with_offset(StackShadowPages*os::vm_page_size());

     } else {

       __ movl(rax, stack_size);

       __ bang_stack_size(rax, rbx);

     }

   } else {

     // need a 5 byte instruction to allow MT safe patching to non-entrant

     __ fat_nop();

   }

   assert(((uintptr_t)__ pc() - start - vep_offset) >= 5,

          "valid size for make_non_entrant");

   // Generate a new frame for the wrapper.

   __ enter();

   // -4 because return address is already present and so is saved rbp,

   if (stack_size - 2*wordSize != 0) {

     __ subq(rsp, stack_size - 2*wordSize);

   }

   // Frame is now completed as far a size and linkage.

   int frame_complete = ((intptr_t)__ pc()) - start;

   int c_arg, j_arg;

   // State of input register args

   bool  live[ConcreteRegisterImpl::number_of_registers];

   live[j_rarg0->as_VMReg()->value()] = false;

   live[j_rarg1->as_VMReg()->value()] = false;

   live[j_rarg2->as_VMReg()->value()] = false;

   live[j_rarg3->as_VMReg()->value()] = false;

   live[j_rarg4->as_VMReg()->value()] = false;

   live[j_rarg5->as_VMReg()->value()] = false;

   live[j_farg0->as_VMReg()->value()] = false;

   live[j_farg1->as_VMReg()->value()] = false;

   live[j_farg2->as_VMReg()->value()] = false;

   live[j_farg3->as_VMReg()->value()] = false;

   live[j_farg4->as_VMReg()->value()] = false;

   live[j_farg5->as_VMReg()->value()] = false;

   live[j_farg6->as_VMReg()->value()] = false;

   live[j_farg7->as_VMReg()->value()] = false;

   bool rax_is_zero = false;

   // All args (except strings) destined for the stack are moved first

   for (j_arg = first_arg_to_pass, c_arg = 0 ;

        j_arg < total_args_passed ; j_arg++, c_arg++ ) {

     VMRegPair src = in_regs[j_arg];

     VMRegPair dst = out_regs[c_arg];

     // Get the real reg value or a dummy (rsp)

     int src_reg = src.first()->is_reg() ?

                   src.first()->value() :

                   rsp->as_VMReg()->value();

     bool useless =  in_sig_bt[j_arg] == T_ARRAY ||

                     (in_sig_bt[j_arg] == T_OBJECT &&

                      out_sig_bt[c_arg] != T_INT &&

                      out_sig_bt[c_arg] != T_ADDRESS &&

                      out_sig_bt[c_arg] != T_LONG);

     live[src_reg] = !useless;

     if (dst.first()->is_stack()) {

       // Even though a string arg in a register is still live after this loop

       // after the string conversion loop (next) it will be dead so we take

       // advantage of that now for simpler code to manage live.

       live[src_reg] = false;

       switch (in_sig_bt[j_arg]) {

         case T_ARRAY:

         case T_OBJECT:

           {

             Address stack_dst(rsp, reg2offset_out(dst.first()));

             if (out_sig_bt[c_arg] == T_INT || out_sig_bt[c_arg] == T_LONG) {

               // need to unbox a one-word value

               Register in_reg = rax;

               if ( src.first()->is_reg() ) {

                 in_reg = src.first()->as_Register();

               } else {

                 __ movq(rax, Address(rbp, reg2offset_in(src.first())));

                 rax_is_zero = false;

               }

               Label skipUnbox;

               __ movptr(Address(rsp, reg2offset_out(dst.first())),

                         (int32_t)NULL_WORD);

               __ testq(in_reg, in_reg);

               __ jcc(Assembler::zero, skipUnbox);

               BasicType bt = out_sig_bt[c_arg];

               int box_offset = java_lang_boxing_object::value_offset_in_bytes(bt);

               Address src1(in_reg, box_offset);

               if ( bt == T_LONG ) {

                 __ movq(in_reg,  src1);

                 __ movq(stack_dst, in_reg);

                 assert(out_sig_bt[c_arg+1] == T_VOID, "must be");

                 ++c_arg; // skip over T_VOID to keep the loop indices in sync

               } else {

                 __ movl(in_reg,  src1);

                 __ movl(stack_dst, in_reg);

               }

               __ bind(skipUnbox);

             } else if (out_sig_bt[c_arg] != T_ADDRESS) {

               // Convert the arg to NULL

               if (!rax_is_zero) {

                 __ xorq(rax, rax);

                 rax_is_zero = true;

               }

               __ movq(stack_dst, rax);

             }

           }

           break;

         case T_VOID:

           break;

         case T_FLOAT:

           // This does the right thing since we know it is destined for the

           // stack

           float_move(masm, src, dst);

           break;

         case T_DOUBLE:

           // This does the right thing since we know it is destined for the

           // stack

           double_move(masm, src, dst);

           break;

         case T_LONG :

           long_move(masm, src, dst);

           break;

         case T_ADDRESS: assert(false, "found T_ADDRESS in java args");

         default:

           move32_64(masm, src, dst);

       }

     }

   }

   // If we have any strings we must store any register based arg to the stack

   // This includes any still live xmm registers too.

   int sid = 0;

   if (total_strings > 0 ) {

     for (j_arg = first_arg_to_pass, c_arg = 0 ;

          j_arg < total_args_passed ; j_arg++, c_arg++ ) {

       VMRegPair src = in_regs[j_arg];

       VMRegPair dst = out_regs[c_arg];

       if (src.first()->is_reg()) {

         Address src_tmp(rbp, fp_offset[src.first()->value()]);

         // string oops were left untouched by the previous loop even if the

         // eventual (converted) arg is destined for the stack so park them

         // away now (except for first)

         if (out_sig_bt[c_arg] == T_ADDRESS) {

           Address utf8_addr = Address(

               rsp, string_locs[sid++] * VMRegImpl::stack_slot_size);

           if (sid != 1) {

             // The first string arg won't be killed until after the utf8

             // conversion

             __ movq(utf8_addr, src.first()->as_Register());

           }

         } else if (dst.first()->is_reg()) {

           if (in_sig_bt[j_arg] == T_FLOAT || in_sig_bt[j_arg] == T_DOUBLE) {

             // Convert the xmm register to an int and store it in the reserved

             // location for the eventual c register arg

             XMMRegister f = src.first()->as_XMMRegister();

             if (in_sig_bt[j_arg] == T_FLOAT) {

               __ movflt(src_tmp, f);

             } else {

               __ movdbl(src_tmp, f);

             }

           } else {

             // If the arg is an oop type we don't support don't bother to store

             // it remember string was handled above.

             bool useless =  in_sig_bt[j_arg] == T_ARRAY ||

                             (in_sig_bt[j_arg] == T_OBJECT &&

                              out_sig_bt[c_arg] != T_INT &&

                              out_sig_bt[c_arg] != T_LONG);

             if (!useless) {

               __ movq(src_tmp, src.first()->as_Register());

             }

           }

         }

       }

       if (in_sig_bt[j_arg] == T_OBJECT && out_sig_bt[c_arg] == T_LONG) {

         assert(out_sig_bt[c_arg+1] == T_VOID, "must be");

         ++c_arg; // skip over T_VOID to keep the loop indices in sync

       }

     }

     // Now that the volatile registers are safe, convert all the strings

     sid = 0;

     for (j_arg = first_arg_to_pass, c_arg = 0 ;

          j_arg < total_args_passed ; j_arg++, c_arg++ ) {

       if (out_sig_bt[c_arg] == T_ADDRESS) {

         // It's a string

         Address utf8_addr = Address(

             rsp, string_locs[sid++] * VMRegImpl::stack_slot_size);

         // The first string we find might still be in the original java arg

         // register

         VMReg src = in_regs[j_arg].first();

         // We will need to eventually save the final argument to the trap

         // in the von-volatile location dedicated to src. This is the offset

         // from fp we will use.

         int src_off = src->is_reg() ?

             fp_offset[src->value()] : reg2offset_in(src);

         // This is where the argument will eventually reside

         VMRegPair dst = out_regs[c_arg];

         if (src->is_reg()) {

           if (sid == 1) {

             __ movq(c_rarg0, src->as_Register());

           } else {

             __ movq(c_rarg0, utf8_addr);

           }

         } else {

           // arg is still in the original location

           __ movq(c_rarg0, Address(rbp, reg2offset_in(src)));

         }

         Label done, convert;

         // see if the oop is NULL

         __ testq(c_rarg0, c_rarg0);

         __ jcc(Assembler::notEqual, convert);

         if (dst.first()->is_reg()) {

           // Save the ptr to utf string in the origina src loc or the tmp

           // dedicated to it

           __ movq(Address(rbp, src_off), c_rarg0);

         } else {

           __ movq(Address(rsp, reg2offset_out(dst.first())), c_rarg0);

         }

         __ jmp(done);

         __ bind(convert);

         __ lea(c_rarg1, utf8_addr);

         if (dst.first()->is_reg()) {

           __ movq(Address(rbp, src_off), c_rarg1);

         } else {

           __ movq(Address(rsp, reg2offset_out(dst.first())), c_rarg1);

         }

         // And do the conversion

         __ call(RuntimeAddress(

                 CAST_FROM_FN_PTR(address, SharedRuntime::get_utf)));

         __ bind(done);

       }

       if (in_sig_bt[j_arg] == T_OBJECT && out_sig_bt[c_arg] == T_LONG) {

         assert(out_sig_bt[c_arg+1] == T_VOID, "must be");

         ++c_arg; // skip over T_VOID to keep the loop indices in sync

       }

     }

     // The get_utf call killed all the c_arg registers

     live[c_rarg0->as_VMReg()->value()] = false;

     live[c_rarg1->as_VMReg()->value()] = false;

     live[c_rarg2->as_VMReg()->value()] = false;

     live[c_rarg3->as_VMReg()->value()] = false;

     live[c_rarg4->as_VMReg()->value()] = false;

     live[c_rarg5->as_VMReg()->value()] = false;

     live[c_farg0->as_VMReg()->value()] = false;

     live[c_farg1->as_VMReg()->value()] = false;

     live[c_farg2->as_VMReg()->value()] = false;

     live[c_farg3->as_VMReg()->value()] = false;

     live[c_farg4->as_VMReg()->value()] = false;

     live[c_farg5->as_VMReg()->value()] = false;

     live[c_farg6->as_VMReg()->value()] = false;

     live[c_farg7->as_VMReg()->value()] = false;

   }

   // Now we can finally move the register args to their desired locations

   rax_is_zero = false;

   for (j_arg = first_arg_to_pass, c_arg = 0 ;

        j_arg < total_args_passed ; j_arg++, c_arg++ ) {

     VMRegPair src = in_regs[j_arg];

     VMRegPair dst = out_regs[c_arg];

     // Only need to look for args destined for the interger registers (since we

     // convert float/double args to look like int/long outbound)

     if (dst.first()->is_reg()) {

       Register r =  dst.first()->as_Register();

       // Check if the java arg is unsupported and thereofre useless

       bool useless =  in_sig_bt[j_arg] == T_ARRAY ||

                       (in_sig_bt[j_arg] == T_OBJECT &&

                        out_sig_bt[c_arg] != T_INT &&

                        out_sig_bt[c_arg] != T_ADDRESS &&

                        out_sig_bt[c_arg] != T_LONG);

       // If we're going to kill an existing arg save it first

       if (live[dst.first()->value()]) {

         // you can't kill yourself

         if (src.first() != dst.first()) {

           __ movq(Address(rbp, fp_offset[dst.first()->value()]), r);

         }

       }

       if (src.first()->is_reg()) {

         if (live[src.first()->value()] ) {

           if (in_sig_bt[j_arg] == T_FLOAT) {

             __ movdl(r, src.first()->as_XMMRegister());

           } else if (in_sig_bt[j_arg] == T_DOUBLE) {

             __ movdq(r, src.first()->as_XMMRegister());

           } else if (r != src.first()->as_Register()) {

             if (!useless) {

               __ movq(r, src.first()->as_Register());

             }

           }

         } else {

           // If the arg is an oop type we don't support don't bother to store

           // it

           if (!useless) {

             if (in_sig_bt[j_arg] == T_DOUBLE ||

                 in_sig_bt[j_arg] == T_LONG  ||

                 in_sig_bt[j_arg] == T_OBJECT ) {

               __ movq(r, Address(rbp, fp_offset[src.first()->value()]));

             } else {

               __ movl(r, Address(rbp, fp_offset[src.first()->value()]));

             }

           }

         }

         live[src.first()->value()] = false;

       } else if (!useless) {

         // full sized move even for int should be ok

         __ movq(r, Address(rbp, reg2offset_in(src.first())));

       }

       // At this point r has the original java arg in the final location

       // (assuming it wasn't useless). If the java arg was an oop

       // we have a bit more to do

       if (in_sig_bt[j_arg] == T_ARRAY || in_sig_bt[j_arg] == T_OBJECT ) {

         if (out_sig_bt[c_arg] == T_INT || out_sig_bt[c_arg] == T_LONG) {

           // need to unbox a one-word value

           Label skip;

           __ testq(r, r);

           __ jcc(Assembler::equal, skip);

           BasicType bt = out_sig_bt[c_arg];

           int box_offset = java_lang_boxing_object::value_offset_in_bytes(bt);

           Address src1(r, box_offset);

           if ( bt == T_LONG ) {

             __ movq(r, src1);

           } else {

             __ movl(r, src1);

           }

           __ bind(skip);

         } else if (out_sig_bt[c_arg] != T_ADDRESS) {

           // Convert the arg to NULL

           __ xorq(r, r);

         }

       }

       // dst can longer be holding an input value

       live[dst.first()->value()] = false;

     }

     if (in_sig_bt[j_arg] == T_OBJECT && out_sig_bt[c_arg] == T_LONG) {

       assert(out_sig_bt[c_arg+1] == T_VOID, "must be");

       ++c_arg; // skip over T_VOID to keep the loop indices in sync

     }

   }

   // Ok now we are done. Need to place the nop that dtrace wants in order to

   // patch in the trap

   int patch_offset = ((intptr_t)__ pc()) - start;

   __ nop();

   // Return

   __ leave();

   __ ret(0);

   __ flush();

   nmethod *nm = nmethod::new_dtrace_nmethod(

       method, masm->code(), vep_offset, patch_offset, frame_complete,

       stack_slots / VMRegImpl::slots_per_word);

   return nm;

 }

 #endif // HAVE_DTRACE_H

 // this function returns the adjust size (in number of words) to a c2i adapter

 // activation for use during deoptimization

 int Deoptimization::last_frame_adjust(int callee_parameters, int callee_locals ) {

   return (callee_locals - callee_parameters) * Interpreter::stackElementWords;

 }

 uint SharedRuntime::out_preserve_stack_slots() {

   return 0;

 }

 //------------------------------generate_deopt_blob----------------------------

 void SharedRuntime::generate_deopt_blob() {

   // Allocate space for the code

   ResourceMark rm;

   // Setup code generation tools

   CodeBuffer buffer("deopt_blob", 2048, 1024);

   MacroAssembler* masm = new MacroAssembler(&buffer);

   int frame_size_in_words;

   OopMap* map = NULL;

   OopMapSet *oop_maps = new OopMapSet();

   // -------------

   // This code enters when returning to a de-optimized nmethod.  A return

   // address has been pushed on the the stack, and return values are in

   // registers.

   // If we are doing a normal deopt then we were called from the patched

   // nmethod from the point we returned to the nmethod. So the return

   // address on the stack is wrong by NativeCall::instruction_size

   // We will adjust the value so it looks like we have the original return

   // address on the stack (like when we eagerly deoptimized).

   // In the case of an exception pending when deoptimizing, we enter

   // with a return address on the stack that points after the call we patched

   // into the exception handler. We have the following register state from,

   // e.g., the forward exception stub (see stubGenerator_x86_64.cpp).

   //    rax: exception oop

   //    rbx: exception handler

   //    rdx: throwing pc

   // So in this case we simply jam rdx into the useless return address and

   // the stack looks just like we want.

   //

   // At this point we need to de-opt.  We save the argument return

   // registers.  We call the first C routine, fetch_unroll_info().  This

   // routine captures the return values and returns a structure which

   // describes the current frame size and the sizes of all replacement frames.

   // The current frame is compiled code and may contain many inlined

   // functions, each with their own JVM state.  We pop the current frame, then

   // push all the new frames.  Then we call the C routine unpack_frames() to

   // populate these frames.  Finally unpack_frames() returns us the new target

   // address.  Notice that callee-save registers are BLOWN here; they have

   // already been captured in the vframeArray at the time the return PC was

   // patched.

   address start = __ pc();

   Label cont;

   // Prolog for non exception case!

   // Save everything in sight.

   map = RegisterSaver::save_live_registers(masm, 0, &frame_size_in_words);

   // Normal deoptimization.  Save exec mode for unpack_frames.

   __ movl(r14, Deoptimization::Unpack_deopt); // callee-saved

   __ jmp(cont);

   int reexecute_offset = __ pc() - start;

   // Reexecute case

   // return address is the pc describes what bci to do re-execute at

   // No need to update map as each call to save_live_registers will produce identical oopmap

   (void) RegisterSaver::save_live_registers(masm, 0, &frame_size_in_words);

   __ movl(r14, Deoptimization::Unpack_reexecute); // callee-saved

   __ jmp(cont);

   int exception_offset = __ pc() - start;

   // Prolog for exception case

   // all registers are dead at this entry point, except for rax, and

   // rdx which contain the exception oop and exception pc

   // respectively.  Set them in TLS and fall thru to the

   // unpack_with_exception_in_tls entry point.

   __ movptr(Address(r15_thread, JavaThread::exception_pc_offset()), rdx);

   __ movptr(Address(r15_thread, JavaThread::exception_oop_offset()), rax);

   int exception_in_tls_offset = __ pc() - start;

   // new implementation because exception oop is now passed in JavaThread

   // Prolog for exception case

   // All registers must be preserved because they might be used by LinearScan

   // Exceptiop oop and throwing PC are passed in JavaThread

   // tos: stack at point of call to method that threw the exception (i.e. only

   // args are on the stack, no return address)

   // make room on stack for the return address

   // It will be patched later with the throwing pc. The correct value is not

   // available now because loading it from memory would destroy registers.

   __ push(0);

   // Save everything in sight.

   map = RegisterSaver::save_live_registers(masm, 0, &frame_size_in_words);

   // Now it is safe to overwrite any register

   // Deopt during an exception.  Save exec mode for unpack_frames.

   __ movl(r14, Deoptimization::Unpack_exception); // callee-saved

   // load throwing pc from JavaThread and patch it as the return address

   // of the current frame. Then clear the field in JavaThread

   __ movptr(rdx, Address(r15_thread, JavaThread::exception_pc_offset()));

   __ movptr(Address(rbp, wordSize), rdx);

   __ movptr(Address(r15_thread, JavaThread::exception_pc_offset()), (int32_t)NULL_WORD);

 #ifdef ASSERT

   // verify that there is really an exception oop in JavaThread

   __ movptr(rax, Address(r15_thread, JavaThread::exception_oop_offset()));

   __ verify_oop(rax);

   // verify that there is no pending exception

   Label no_pending_exception;

   __ movptr(rax, Address(r15_thread, Thread::pending_exception_offset()));

   __ testptr(rax, rax);

   __ jcc(Assembler::zero, no_pending_exception);

   __ stop("must not have pending exception here");

   __ bind(no_pending_exception);

 #endif

   __ bind(cont);

   // Call C code.  Need thread and this frame, but NOT official VM entry

   // crud.  We cannot block on this call, no GC can happen.

   //

   // UnrollBlock* fetch_unroll_info(JavaThread* thread)