Remove peephole optimiziations from IA32 and ARM assembler.

src/ia32/assembler-ia32.cc

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions
 // are met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 323 matching lines @@
   if (own_buffer_) {
     memset(buffer_, 0xCC, buffer_size);  // int3
   }
 #endif
 
   // Setup buffer pointers.
   ASSERT(buffer_ != NULL);
   pc_ = buffer_;
   reloc_info_writer.Reposition(buffer_ + buffer_size, pc_);
 
-  last_pc_ = NULL;
 #ifdef GENERATED_CODE_COVERAGE
   InitCoverageLog();
 #endif
 }
 
 
 Assembler::~Assembler() {
   if (own_buffer_) {
     if (isolate()->assembler_spare_buffer() == NULL &&
         buffer_size_ == kMinimalBufferSize) {
@@ skipping 27 matching lines @@
 
 
 void Assembler::CodeTargetAlign() {
   Align(16);  // Preferred alignment of jump targets on ia32.
 }
 
 
 void Assembler::cpuid() {
   ASSERT(CpuFeatures::IsEnabled(CPUID));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x0F);
   EMIT(0xA2);
 }
 
 
 void Assembler::pushad() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x60);
 }
 
 
 void Assembler::popad() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x61);
 }
 
 
 void Assembler::pushfd() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x9C);
 }
 
 
 void Assembler::popfd() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x9D);
 }
 
 
 void Assembler::push(const Immediate& x) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   if (x.is_int8()) {
     EMIT(0x6a);
     EMIT(x.x_);
   } else {
     EMIT(0x68);
     emit(x);
   }
 }
 
 
 void Assembler::push_imm32(int32_t imm32) {
   EnsureSpace ensure_space(this);
   EMIT(0x68);
   emit(imm32);
 }
 
 
 void Assembler::push(Register src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x50 | src.code());
 }
 
 
 void Assembler::push(const Operand& src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xFF);
   emit_operand(esi, src);
 }
 
 
 void Assembler::pop(Register dst) {
   ASSERT(reloc_info_writer.last_pc() != NULL);
-  if (FLAG_peephole_optimization && (reloc_info_writer.last_pc() <= last_pc_)) {
-    // (last_pc_ != NULL) is rolled into the above check.
-    // If a last_pc_ is set, we need to make sure that there has not been any
-    // relocation information generated between the last instruction and this
-    // pop instruction.
-    byte instr = last_pc_[0];
-    if ((instr & ~0x7) == 0x50) {
-      int push_reg_code = instr & 0x7;
-      if (push_reg_code == dst.code()) {
-        pc_ = last_pc_;
-        if (FLAG_print_peephole_optimization) {
-          PrintF("%d push/pop (same reg) eliminated\n", pc_offset());
-        }
-      } else {
-        // Convert 'push src; pop dst' to 'mov dst, src'.
-        last_pc_[0] = 0x8b;
-        Register src = { push_reg_code };
-        EnsureSpace ensure_space(this);
-        emit_operand(dst, Operand(src));
-        if (FLAG_print_peephole_optimization) {
-          PrintF("%d push/pop (reg->reg) eliminated\n", pc_offset());
-        }
-      }
-      last_pc_ = NULL;
-      return;
-    } else if (instr == 0xff) {  // push of an operand, convert to a move
-      byte op1 = last_pc_[1];
-      // Check if the operation is really a push.
-      if ((op1 & 0x38) == (6 << 3)) {
-        op1 = (op1 & ~0x38) | static_cast<byte>(dst.code() << 3);
-        last_pc_[0] = 0x8b;
-        last_pc_[1] = op1;
-        last_pc_ = NULL;
-        if (FLAG_print_peephole_optimization) {
-          PrintF("%d push/pop (op->reg) eliminated\n", pc_offset());
-        }
-        return;
-      }
-    } else if ((instr == 0x89) &&
-               (last_pc_[1] == 0x04) &&
-               (last_pc_[2] == 0x24)) {
-      // 0x71283c   396  890424         mov [esp],eax
-      // 0x71283f   399  58             pop eax
-      if (dst.is(eax)) {
-        // change to
-        // 0x710fac   216  83c404         add esp,0x4
-        last_pc_[0] = 0x83;
-        last_pc_[1] = 0xc4;
-        last_pc_[2] = 0x04;
-        last_pc_ = NULL;
-        if (FLAG_print_peephole_optimization) {
-          PrintF("%d push/pop (mov-pop) eliminated\n", pc_offset());
-        }
-        return;
-      }
-    } else if (instr == 0x6a && dst.is(eax)) {  // push of immediate 8 bit
-      byte imm8 = last_pc_[1];
-      if (imm8 == 0) {
-        // 6a00         push 0x0
-        // 58           pop eax
-        last_pc_[0] = 0x31;
-        last_pc_[1] = 0xc0;
-        // change to
-        // 31c0         xor eax,eax
-        last_pc_ = NULL;
-        if (FLAG_print_peephole_optimization) {
-          PrintF("%d push/pop (imm->reg) eliminated\n", pc_offset());
-        }
-        return;
-      } else {
-        // 6a00         push 0xXX
-        // 58           pop eax
-        last_pc_[0] = 0xb8;
-        EnsureSpace ensure_space(this);
-        if ((imm8 & 0x80) != 0) {
-          EMIT(0xff);
-          EMIT(0xff);
-          EMIT(0xff);
-          // change to
-          // b8XXffffff   mov eax,0xffffffXX
-        } else {
-          EMIT(0x00);
-          EMIT(0x00);
-          EMIT(0x00);
-          // change to
-          // b8XX000000   mov eax,0x000000XX
-        }
-        last_pc_ = NULL;
-        if (FLAG_print_peephole_optimization) {
-          PrintF("%d push/pop (imm->reg) eliminated\n", pc_offset());
-        }
-        return;
-      }
-    } else if (instr == 0x68 && dst.is(eax)) {  // push of immediate 32 bit
-      // 68XXXXXXXX   push 0xXXXXXXXX
-      // 58           pop eax
-      last_pc_[0] = 0xb8;
-      last_pc_ = NULL;
-      // change to
-      // b8XXXXXXXX   mov eax,0xXXXXXXXX
-      if (FLAG_print_peephole_optimization) {
-        PrintF("%d push/pop (imm->reg) eliminated\n", pc_offset());
-      }
-      return;
-    }
-
-    // Other potential patterns for peephole:
-    // 0x712716   102  890424         mov [esp], eax
-    // 0x712719   105  8b1424         mov edx, [esp]
-  }
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x58 | dst.code());
 }
 
 
 void Assembler::pop(const Operand& dst) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x8F);
   emit_operand(eax, dst);
 }
 
 
 void Assembler::enter(const Immediate& size) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xC8);
   emit_w(size);
   EMIT(0);
 }
 
 
 void Assembler::leave() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xC9);
 }
 
 
 void Assembler::mov_b(Register dst, const Operand& src) {
   ASSERT(dst.code() < 4);
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x8A);
   emit_operand(dst, src);
 }
 
 
 void Assembler::mov_b(const Operand& dst, int8_t imm8) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xC6);
   emit_operand(eax, dst);
   EMIT(imm8);
 }
 
 
 void Assembler::mov_b(const Operand& dst, Register src) {
   ASSERT(src.code() < 4);
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x88);
   emit_operand(src, dst);
 }
 
 
 void Assembler::mov_w(Register dst, const Operand& src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x8B);
   emit_operand(dst, src);
 }
 
 
 void Assembler::mov_w(const Operand& dst, Register src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x89);
   emit_operand(src, dst);
 }
 
 
 void Assembler::mov(Register dst, int32_t imm32) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xB8 | dst.code());
   emit(imm32);
 }
 
 
 void Assembler::mov(Register dst, const Immediate& x) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xB8 | dst.code());
   emit(x);
 }
 
 
 void Assembler::mov(Register dst, Handle<Object> handle) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xB8 | dst.code());
   emit(handle);
 }
 
 
 void Assembler::mov(Register dst, const Operand& src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x8B);
   emit_operand(dst, src);
 }
 
 
 void Assembler::mov(Register dst, Register src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x89);
   EMIT(0xC0 | src.code() << 3 | dst.code());
 }
 
 
 void Assembler::mov(const Operand& dst, const Immediate& x) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xC7);
   emit_operand(eax, dst);
   emit(x);
 }
 
 
 void Assembler::mov(const Operand& dst, Handle<Object> handle) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xC7);
   emit_operand(eax, dst);
   emit(handle);
 }
 
 
 void Assembler::mov(const Operand& dst, Register src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x89);
   emit_operand(src, dst);
 }
 
 
 void Assembler::movsx_b(Register dst, const Operand& src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x0F);
   EMIT(0xBE);
   emit_operand(dst, src);
 }
 
 
 void Assembler::movsx_w(Register dst, const Operand& src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x0F);
   EMIT(0xBF);
   emit_operand(dst, src);
 }
 
 
 void Assembler::movzx_b(Register dst, const Operand& src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x0F);
   EMIT(0xB6);
   emit_operand(dst, src);
 }
 
 
 void Assembler::movzx_w(Register dst, const Operand& src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x0F);
   EMIT(0xB7);
   emit_operand(dst, src);
 }
 
 
 void Assembler::cmov(Condition cc, Register dst, int32_t imm32) {
   ASSERT(CpuFeatures::IsEnabled(CMOV));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   UNIMPLEMENTED();
   USE(cc);
   USE(dst);
   USE(imm32);
 }
 
 
 void Assembler::cmov(Condition cc, Register dst, Handle<Object> handle) {
   ASSERT(CpuFeatures::IsEnabled(CMOV));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   UNIMPLEMENTED();
   USE(cc);
   USE(dst);
   USE(handle);
 }
 
 
 void Assembler::cmov(Condition cc, Register dst, const Operand& src) {
   ASSERT(CpuFeatures::IsEnabled(CMOV));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   // Opcode: 0f 40 + cc /r.
   EMIT(0x0F);
   EMIT(0x40 + cc);
   emit_operand(dst, src);
 }
 
 
 void Assembler::cld() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xFC);
 }
 
 
 void Assembler::rep_movs() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF3);
   EMIT(0xA5);
 }
 
 
 void Assembler::rep_stos() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF3);
   EMIT(0xAB);
 }
 
 
 void Assembler::stos() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xAB);
 }
 
 
 void Assembler::xchg(Register dst, Register src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   if (src.is(eax) || dst.is(eax)) {  // Single-byte encoding.
     EMIT(0x90 | (src.is(eax) ? dst.code() : src.code()));
   } else {
     EMIT(0x87);
     EMIT(0xC0 | src.code() << 3 | dst.code());
   }
 }
 
 
 void Assembler::adc(Register dst, int32_t imm32) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_arith(2, Operand(dst), Immediate(imm32));
 }
 
 
 void Assembler::adc(Register dst, const Operand& src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x13);
   emit_operand(dst, src);
 }
 
 
 void Assembler::add(Register dst, const Operand& src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x03);
   emit_operand(dst, src);
 }
 
 
 void Assembler::add(const Operand& dst, const Immediate& x) {
   ASSERT(reloc_info_writer.last_pc() != NULL);
-  if (FLAG_peephole_optimization && (reloc_info_writer.last_pc() <= last_pc_)) {
-    byte instr = last_pc_[0];
-    if ((instr & 0xf8) == 0x50) {
-      // Last instruction was a push. Check whether this is a pop without a
-      // result.
-      if ((dst.is_reg(esp)) &&
-          (x.x_ == kPointerSize) && (x.rmode_ == RelocInfo::NONE)) {
-        pc_ = last_pc_;
-        last_pc_ = NULL;
-        if (FLAG_print_peephole_optimization) {
-          PrintF("%d push/pop(noreg) eliminated\n", pc_offset());
-        }
-        return;
-      }
-    }
-  }
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_arith(0, dst, x);
 }
 
 
 void Assembler::and_(Register dst, int32_t imm32) {
   and_(dst, Immediate(imm32));
 }
 
 
 void Assembler::and_(Register dst, const Immediate& x) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_arith(4, Operand(dst), x);
 }
 
 
 void Assembler::and_(Register dst, const Operand& src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x23);
   emit_operand(dst, src);
 }
 
 
 void Assembler::and_(const Operand& dst, const Immediate& x) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_arith(4, dst, x);
 }
 
 
 void Assembler::and_(const Operand& dst, Register src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x21);
   emit_operand(src, dst);
 }
 
 
 void Assembler::cmpb(const Operand& op, int8_t imm8) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x80);
   emit_operand(edi, op);  // edi == 7
   EMIT(imm8);
 }
 
 
 void Assembler::cmpb(const Operand& dst, Register src) {
   ASSERT(src.is_byte_register());
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x38);
   emit_operand(src, dst);
 }
 
 
 void Assembler::cmpb(Register dst, const Operand& src) {
   ASSERT(dst.is_byte_register());
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x3A);
   emit_operand(dst, src);
 }
 
 
 void Assembler::cmpw(const Operand& op, Immediate imm16) {
   ASSERT(imm16.is_int16());
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x81);
   emit_operand(edi, op);
   emit_w(imm16);
 }
 
 
 void Assembler::cmp(Register reg, int32_t imm32) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_arith(7, Operand(reg), Immediate(imm32));
 }
 
 
 void Assembler::cmp(Register reg, Handle<Object> handle) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_arith(7, Operand(reg), Immediate(handle));
 }
 
 
 void Assembler::cmp(Register reg, const Operand& op) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x3B);
   emit_operand(reg, op);
 }
 
 
 void Assembler::cmp(const Operand& op, const Immediate& imm) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_arith(7, op, imm);
 }
 
 
 void Assembler::cmp(const Operand& op, Handle<Object> handle) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_arith(7, op, Immediate(handle));
 }
 
 
 void Assembler::cmpb_al(const Operand& op) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x38);  // CMP r/m8, r8
   emit_operand(eax, op);  // eax has same code as register al.
 }
 
 
 void Assembler::cmpw_ax(const Operand& op) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x39);  // CMP r/m16, r16
   emit_operand(eax, op);  // eax has same code as register ax.
 }
 
 
 void Assembler::dec_b(Register dst) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xFE);
   EMIT(0xC8 | dst.code());
 }
 
 
 void Assembler::dec_b(const Operand& dst) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xFE);
   emit_operand(ecx, dst);
 }
 
 
 void Assembler::dec(Register dst) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x48 | dst.code());
 }
 
 
 void Assembler::dec(const Operand& dst) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xFF);
   emit_operand(ecx, dst);
 }
 
 
 void Assembler::cdq() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x99);
 }
 
 
 void Assembler::idiv(Register src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF7);
   EMIT(0xF8 | src.code());
 }
 
 
 void Assembler::imul(Register reg) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF7);
   EMIT(0xE8 | reg.code());
 }
 
 
 void Assembler::imul(Register dst, const Operand& src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x0F);
   EMIT(0xAF);
   emit_operand(dst, src);
 }
 
 
 void Assembler::imul(Register dst, Register src, int32_t imm32) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   if (is_int8(imm32)) {
     EMIT(0x6B);
     EMIT(0xC0 | dst.code() << 3 | src.code());
     EMIT(imm32);
   } else {
     EMIT(0x69);
     EMIT(0xC0 | dst.code() << 3 | src.code());
     emit(imm32);
   }
 }
 
 
 void Assembler::inc(Register dst) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x40 | dst.code());
 }
 
 
 void Assembler::inc(const Operand& dst) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xFF);
   emit_operand(eax, dst);
 }
 
 
 void Assembler::lea(Register dst, const Operand& src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x8D);
   emit_operand(dst, src);
 }
 
 
 void Assembler::mul(Register src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF7);
   EMIT(0xE0 | src.code());
 }
 
 
 void Assembler::neg(Register dst) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF7);
   EMIT(0xD8 | dst.code());
 }
 
 
 void Assembler::not_(Register dst) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF7);
   EMIT(0xD0 | dst.code());
 }
 
 
 void Assembler::or_(Register dst, int32_t imm32) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_arith(1, Operand(dst), Immediate(imm32));
 }
 
 
 void Assembler::or_(Register dst, const Operand& src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x0B);
   emit_operand(dst, src);
 }
 
 
 void Assembler::or_(const Operand& dst, const Immediate& x) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_arith(1, dst, x);
 }
 
 
 void Assembler::or_(const Operand& dst, Register src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x09);
   emit_operand(src, dst);
 }
 
 
 void Assembler::rcl(Register dst, uint8_t imm8) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   ASSERT(is_uint5(imm8));  // illegal shift count
   if (imm8 == 1) {
     EMIT(0xD1);
     EMIT(0xD0 | dst.code());
   } else {
     EMIT(0xC1);
     EMIT(0xD0 | dst.code());
     EMIT(imm8);
   }
 }
 
 
 void Assembler::rcr(Register dst, uint8_t imm8) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   ASSERT(is_uint5(imm8));  // illegal shift count
   if (imm8 == 1) {
     EMIT(0xD1);
     EMIT(0xD8 | dst.code());
   } else {
     EMIT(0xC1);
     EMIT(0xD8 | dst.code());
     EMIT(imm8);
   }
 }
 
 
 void Assembler::sar(Register dst, uint8_t imm8) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   ASSERT(is_uint5(imm8));  // illegal shift count
   if (imm8 == 1) {
     EMIT(0xD1);
     EMIT(0xF8 | dst.code());
   } else {
     EMIT(0xC1);
     EMIT(0xF8 | dst.code());
     EMIT(imm8);
   }
 }
 
 
 void Assembler::sar_cl(Register dst) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xD3);
   EMIT(0xF8 | dst.code());
 }
 
 
 void Assembler::sbb(Register dst, const Operand& src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x1B);
   emit_operand(dst, src);
 }
 
 
 void Assembler::shld(Register dst, const Operand& src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x0F);
   EMIT(0xA5);
   emit_operand(dst, src);
 }
 
 
 void Assembler::shl(Register dst, uint8_t imm8) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   ASSERT(is_uint5(imm8));  // illegal shift count
   if (imm8 == 1) {
     EMIT(0xD1);
     EMIT(0xE0 | dst.code());
   } else {
     EMIT(0xC1);
     EMIT(0xE0 | dst.code());
     EMIT(imm8);
   }
 }
 
 
 void Assembler::shl_cl(Register dst) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xD3);
   EMIT(0xE0 | dst.code());
 }
 
 
 void Assembler::shrd(Register dst, const Operand& src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x0F);
   EMIT(0xAD);
   emit_operand(dst, src);
 }
 
 
 void Assembler::shr(Register dst, uint8_t imm8) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   ASSERT(is_uint5(imm8));  // illegal shift count
   if (imm8 == 1) {
     EMIT(0xD1);
     EMIT(0xE8 | dst.code());
   } else {
     EMIT(0xC1);
     EMIT(0xE8 | dst.code());
     EMIT(imm8);
   }
 }
 
 
 void Assembler::shr_cl(Register dst) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xD3);
   EMIT(0xE8 | dst.code());
 }
 
 
 void Assembler::subb(const Operand& op, int8_t imm8) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   if (op.is_reg(eax)) {
     EMIT(0x2c);
   } else {
     EMIT(0x80);
     emit_operand(ebp, op);  // ebp == 5
   }
   EMIT(imm8);
 }
 
 
 void Assembler::sub(const Operand& dst, const Immediate& x) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_arith(5, dst, x);
 }
 
 
 void Assembler::sub(Register dst, const Operand& src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x2B);
   emit_operand(dst, src);
 }
 
 
 void Assembler::subb(Register dst, const Operand& src) {
   ASSERT(dst.code() < 4);
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x2A);
   emit_operand(dst, src);
 }
 
 
 void Assembler::sub(const Operand& dst, Register src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x29);
   emit_operand(src, dst);
 }
 
 
 void Assembler::test(Register reg, const Immediate& imm) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   // Only use test against byte for registers that have a byte
   // variant: eax, ebx, ecx, and edx.
   if (imm.rmode_ == RelocInfo::NONE && is_uint8(imm.x_) && reg.code() < 4) {
     uint8_t imm8 = imm.x_;
     if (reg.is(eax)) {
       EMIT(0xA8);
       EMIT(imm8);
     } else {
       emit_arith_b(0xF6, 0xC0, reg, imm8);
     }
   } else {
     // This is not using emit_arith because test doesn't support
     // sign-extension of 8-bit operands.
     if (reg.is(eax)) {
       EMIT(0xA9);
     } else {
       EMIT(0xF7);
       EMIT(0xC0 | reg.code());
     }
     emit(imm);
   }
 }
 
 
 void Assembler::test(Register reg, const Operand& op) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x85);
   emit_operand(reg, op);
 }
 
 
 void Assembler::test_b(Register reg, const Operand& op) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x84);
   emit_operand(reg, op);
 }
 
 
 void Assembler::test(const Operand& op, const Immediate& imm) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF7);
   emit_operand(eax, op);
   emit(imm);
 }
 
 
 void Assembler::test_b(const Operand& op, uint8_t imm8) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF6);
   emit_operand(eax, op);
   EMIT(imm8);
 }
 
 
 void Assembler::xor_(Register dst, int32_t imm32) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_arith(6, Operand(dst), Immediate(imm32));
 }
 
 
 void Assembler::xor_(Register dst, const Operand& src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x33);
   emit_operand(dst, src);
 }
 
 
 void Assembler::xor_(const Operand& src, Register dst) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x31);
   emit_operand(dst, src);
 }
 
 
 void Assembler::xor_(const Operand& dst, const Immediate& x) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_arith(6, dst, x);
 }
 
 
 void Assembler::bt(const Operand& dst, Register src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x0F);
   EMIT(0xA3);
   emit_operand(src, dst);
 }
 
 
 void Assembler::bts(const Operand& dst, Register src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x0F);
   EMIT(0xAB);
   emit_operand(src, dst);
 }
 
 
 void Assembler::hlt() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF4);
 }
 
 
 void Assembler::int3() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xCC);
 }
 
 
 void Assembler::nop() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x90);
 }
 
 
 void Assembler::rdtsc() {
   ASSERT(CpuFeatures::IsEnabled(RDTSC));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x0F);
   EMIT(0x31);
 }
 
 
 void Assembler::ret(int imm16) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   ASSERT(is_uint16(imm16));
   if (imm16 == 0) {
     EMIT(0xC3);
   } else {
     EMIT(0xC2);
     EMIT(imm16 & 0xFF);
     EMIT((imm16 >> 8) & 0xFF);
   }
 }
 
@@ skipping 25 matching lines @@
       disp.next(&l);
     }
   } else {
     PrintF("label in inconsistent state (pos = %d)\n", L->pos_);
   }
 }
 
 
 void Assembler::bind_to(Label* L, int pos) {
   EnsureSpace ensure_space(this);
-  last_pc_ = NULL;
   ASSERT(0 <= pos && pos <= pc_offset());  // must have a valid binding position
   while (L->is_linked()) {
     Displacement disp = disp_at(L);
     int fixup_pos = L->pos();
     if (disp.type() == Displacement::CODE_RELATIVE) {
       // Relative to Code* heap object pointer.
       long_at_put(fixup_pos, pos + Code::kHeaderSize - kHeapObjectTag);
     } else {
       if (disp.type() == Displacement::UNCONDITIONAL_JUMP) {
         ASSERT(byte_at(fixup_pos - 1) == 0xE9);  // jmp expected
@@ skipping 18 matching lines @@
     } else {
       L->UnuseNear();
     }
   }
   L->bind_to(pos);
 }
 
 
 void Assembler::bind(Label* L) {
   EnsureSpace ensure_space(this);
-  last_pc_ = NULL;
   ASSERT(!L->is_bound());  // label can only be bound once
   bind_to(L, pc_offset());
 }
 
 
 void Assembler::call(Label* L) {
   positions_recorder()->WriteRecordedPositions();
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   if (L->is_bound()) {
     const int long_size = 5;
     int offs = L->pos() - pc_offset();
     ASSERT(offs <= 0);
     // 1110 1000 #32-bit disp.
     EMIT(0xE8);
     emit(offs - long_size);
   } else {
     // 1110 1000 #32-bit disp.
     EMIT(0xE8);
     emit_disp(L, Displacement::OTHER);
   }
 }
 
 
 void Assembler::call(byte* entry, RelocInfo::Mode rmode) {
   positions_recorder()->WriteRecordedPositions();
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   ASSERT(!RelocInfo::IsCodeTarget(rmode));
   EMIT(0xE8);
   emit(entry - (pc_ + sizeof(int32_t)), rmode);
 }
 
 
 int Assembler::CallSize(const Operand& adr) {
   // Call size is 1 (opcode) + adr.len_ (operand).
   return 1 + adr.len_;
 }
 
 
 void Assembler::call(const Operand& adr) {
   positions_recorder()->WriteRecordedPositions();
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xFF);
   emit_operand(edx, adr);
-  ASSERT(pc_ - last_pc_ == CallSize(adr));
 }
 
 
 int Assembler::CallSize(Handle<Code> code, RelocInfo::Mode rmode) {
   return 1 /* EMIT */ + sizeof(uint32_t) /* emit */;
 }
 
 
 void Assembler::call(Handle<Code> code,
                      RelocInfo::Mode rmode,
                      unsigned ast_id) {
   positions_recorder()->WriteRecordedPositions();
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   ASSERT(RelocInfo::IsCodeTarget(rmode));
   EMIT(0xE8);
   emit(reinterpret_cast<intptr_t>(code.location()), rmode, ast_id);
 }
 
 
 void Assembler::jmp(Label* L, Label::Distance distance) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   if (L->is_bound()) {
     const int short_size = 2;
     const int long_size  = 5;
     int offs = L->pos() - pc_offset();
     ASSERT(offs <= 0);
     if (is_int8(offs - short_size)) {
       // 1110 1011 #8-bit disp.
       EMIT(0xEB);
       EMIT((offs - short_size) & 0xFF);
     } else {
       // 1110 1001 #32-bit disp.
       EMIT(0xE9);
       emit(offs - long_size);
     }
   } else if (distance == Label::kNear) {
     EMIT(0xEB);
     emit_near_disp(L);
   } else {
     // 1110 1001 #32-bit disp.
     EMIT(0xE9);
     emit_disp(L, Displacement::UNCONDITIONAL_JUMP);
   }
 }
 
 
 void Assembler::jmp(byte* entry, RelocInfo::Mode rmode) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   ASSERT(!RelocInfo::IsCodeTarget(rmode));
   EMIT(0xE9);
   emit(entry - (pc_ + sizeof(int32_t)), rmode);
 }
 
 
 void Assembler::jmp(const Operand& adr) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xFF);
   emit_operand(esp, adr);
 }
 
 
 void Assembler::jmp(Handle<Code> code, RelocInfo::Mode rmode) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   ASSERT(RelocInfo::IsCodeTarget(rmode));
   EMIT(0xE9);
   emit(reinterpret_cast<intptr_t>(code.location()), rmode);
 }
 
 
 void Assembler::j(Condition cc, Label* L, Hint hint, Label::Distance distance) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   ASSERT(0 <= cc && cc < 16);
   if (FLAG_emit_branch_hints && hint != no_hint) EMIT(hint);
   if (L->is_bound()) {
     const int short_size = 2;
     const int long_size  = 6;
     int offs = L->pos() - pc_offset();
     ASSERT(offs <= 0);
     if (is_int8(offs - short_size)) {
       // 0111 tttn #8-bit disp
       EMIT(0x70 | cc);
@@ skipping 13 matching lines @@
     //       is the same however, seems to be rather unlikely case.
     EMIT(0x0F);
     EMIT(0x80 | cc);
     emit_disp(L, Displacement::OTHER);
   }
 }
 
 
 void Assembler::j(Condition cc, byte* entry, RelocInfo::Mode rmode, Hint hint) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   ASSERT((0 <= cc) && (cc < 16));
   if (FLAG_emit_branch_hints && hint != no_hint) EMIT(hint);
   // 0000 1111 1000 tttn #32-bit disp.
   EMIT(0x0F);
   EMIT(0x80 | cc);
   emit(entry - (pc_ + sizeof(int32_t)), rmode);
 }
 
 
 void Assembler::j(Condition cc, Handle<Code> code, Hint hint) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   if (FLAG_emit_branch_hints && hint != no_hint) EMIT(hint);
   // 0000 1111 1000 tttn #32-bit disp
   EMIT(0x0F);
   EMIT(0x80 | cc);
   emit(reinterpret_cast<intptr_t>(code.location()), RelocInfo::CODE_TARGET);
 }
 
 
 // FPU instructions.
 
 void Assembler::fld(int i) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_farith(0xD9, 0xC0, i);
 }
 
 
 void Assembler::fstp(int i) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_farith(0xDD, 0xD8, i);
 }
 
 
 void Assembler::fld1() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xD9);
   EMIT(0xE8);
 }
 
 
 void Assembler::fldpi() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xD9);
   EMIT(0xEB);
 }
 
 
 void Assembler::fldz() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xD9);
   EMIT(0xEE);
 }
 
 
 void Assembler::fldln2() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xD9);
   EMIT(0xED);
 }
 
 
 void Assembler::fld_s(const Operand& adr) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xD9);
   emit_operand(eax, adr);
 }
 
 
 void Assembler::fld_d(const Operand& adr) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xDD);
   emit_operand(eax, adr);
 }
 
 
 void Assembler::fstp_s(const Operand& adr) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xD9);
   emit_operand(ebx, adr);
 }
 
 
 void Assembler::fstp_d(const Operand& adr) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xDD);
   emit_operand(ebx, adr);
 }
 
 
 void Assembler::fst_d(const Operand& adr) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xDD);
   emit_operand(edx, adr);
 }
 
 
 void Assembler::fild_s(const Operand& adr) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xDB);
   emit_operand(eax, adr);
 }
 
 
 void Assembler::fild_d(const Operand& adr) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xDF);
   emit_operand(ebp, adr);
 }
 
 
 void Assembler::fistp_s(const Operand& adr) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xDB);
   emit_operand(ebx, adr);
 }
 
 
 void Assembler::fisttp_s(const Operand& adr) {
   ASSERT(CpuFeatures::IsEnabled(SSE3));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xDB);
   emit_operand(ecx, adr);
 }
 
 
 void Assembler::fisttp_d(const Operand& adr) {
   ASSERT(CpuFeatures::IsEnabled(SSE3));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xDD);
   emit_operand(ecx, adr);
 }
 
 
 void Assembler::fist_s(const Operand& adr) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xDB);
   emit_operand(edx, adr);
 }
 
 
 void Assembler::fistp_d(const Operand& adr) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xDF);
   emit_operand(edi, adr);
 }
 
 
 void Assembler::fabs() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xD9);
   EMIT(0xE1);
 }
 
 
 void Assembler::fchs() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xD9);
   EMIT(0xE0);
 }
 
 
 void Assembler::fcos() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xD9);
   EMIT(0xFF);
 }
 
 
 void Assembler::fsin() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xD9);
   EMIT(0xFE);
 }
 
 
 void Assembler::fyl2x() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xD9);
   EMIT(0xF1);
 }
 
 
 void Assembler::fadd(int i) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_farith(0xDC, 0xC0, i);
 }
 
 
 void Assembler::fsub(int i) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_farith(0xDC, 0xE8, i);
 }
 
 
 void Assembler::fisub_s(const Operand& adr) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xDA);
   emit_operand(esp, adr);
 }
 
 
 void Assembler::fmul(int i) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_farith(0xDC, 0xC8, i);
 }
 
 
 void Assembler::fdiv(int i) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_farith(0xDC, 0xF8, i);
 }
 
 
 void Assembler::faddp(int i) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_farith(0xDE, 0xC0, i);
 }
 
 
 void Assembler::fsubp(int i) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_farith(0xDE, 0xE8, i);
 }
 
 
 void Assembler::fsubrp(int i) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_farith(0xDE, 0xE0, i);
 }
 
 
 void Assembler::fmulp(int i) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_farith(0xDE, 0xC8, i);
 }
 
 
 void Assembler::fdivp(int i) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_farith(0xDE, 0xF8, i);
 }
 
 
 void Assembler::fprem() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xD9);
   EMIT(0xF8);
 }
 
 
 void Assembler::fprem1() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xD9);
   EMIT(0xF5);
 }
 
 
 void Assembler::fxch(int i) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_farith(0xD9, 0xC8, i);
 }
 
 
 void Assembler::fincstp() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xD9);
   EMIT(0xF7);
 }
 
 
 void Assembler::ffree(int i) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_farith(0xDD, 0xC0, i);
 }
 
 
 void Assembler::ftst() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xD9);
   EMIT(0xE4);
 }
 
 
 void Assembler::fucomp(int i) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   emit_farith(0xDD, 0xE8, i);
 }
 
 
 void Assembler::fucompp() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xDA);
   EMIT(0xE9);
 }
 
 
 void Assembler::fucomi(int i) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xDB);
   EMIT(0xE8 + i);
 }
 
 
 void Assembler::fucomip() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xDF);
   EMIT(0xE9);
 }
 
 
 void Assembler::fcompp() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xDE);
   EMIT(0xD9);
 }
 
 
 void Assembler::fnstsw_ax() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xDF);
   EMIT(0xE0);
 }
 
 
 void Assembler::fwait() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x9B);
 }
 
 
 void Assembler::frndint() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xD9);
   EMIT(0xFC);
 }
 
 
 void Assembler::fnclex() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xDB);
   EMIT(0xE2);
 }
 
 
 void Assembler::sahf() {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x9E);
 }
 
 
 void Assembler::setcc(Condition cc, Register reg) {
   ASSERT(reg.is_byte_register());
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x0F);
   EMIT(0x90 | cc);
   EMIT(0xC0 | reg.code());
 }
 
 
 void Assembler::cvttss2si(Register dst, const Operand& src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF3);
   EMIT(0x0F);
   EMIT(0x2C);
   emit_operand(dst, src);
 }
 
 
 void Assembler::cvttsd2si(Register dst, const Operand& src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF2);
   EMIT(0x0F);
   EMIT(0x2C);
   emit_operand(dst, src);
 }
 
 
 void Assembler::cvtsi2sd(XMMRegister dst, const Operand& src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF2);
   EMIT(0x0F);
   EMIT(0x2A);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::cvtss2sd(XMMRegister dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF3);
   EMIT(0x0F);
   EMIT(0x5A);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::cvtsd2ss(XMMRegister dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF2);
   EMIT(0x0F);
   EMIT(0x5A);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::addsd(XMMRegister dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF2);
   EMIT(0x0F);
   EMIT(0x58);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::mulsd(XMMRegister dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF2);
   EMIT(0x0F);
   EMIT(0x59);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::subsd(XMMRegister dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF2);
   EMIT(0x0F);
   EMIT(0x5C);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::divsd(XMMRegister dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF2);
   EMIT(0x0F);
   EMIT(0x5E);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::xorpd(XMMRegister dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0x57);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::xorps(XMMRegister dst, XMMRegister src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x0F);
   EMIT(0x57);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::sqrtsd(XMMRegister dst, XMMRegister src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF2);
   EMIT(0x0F);
   EMIT(0x51);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::andpd(XMMRegister dst, XMMRegister src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0x54);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::ucomisd(XMMRegister dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0x2E);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::movmskpd(Register dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0x50);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::cmpltsd(XMMRegister dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF2);
   EMIT(0x0F);
   EMIT(0xC2);
   emit_sse_operand(dst, src);
   EMIT(1);  // LT == 1
 }
 
 
 void Assembler::movaps(XMMRegister dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x0F);
   EMIT(0x28);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::movdqa(const Operand& dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0x7F);
   emit_sse_operand(src, dst);
 }
 
 
 void Assembler::movdqa(XMMRegister dst, const Operand& src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0x6F);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::movdqu(const Operand& dst, XMMRegister src ) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF3);
   EMIT(0x0F);
   EMIT(0x7F);
   emit_sse_operand(src, dst);
 }
 
 
 void Assembler::movdqu(XMMRegister dst, const Operand& src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF3);
   EMIT(0x0F);
   EMIT(0x6F);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::movntdqa(XMMRegister dst, const Operand& src) {
   ASSERT(CpuFeatures::IsEnabled(SSE4_1));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0x38);
   EMIT(0x2A);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::movntdq(const Operand& dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0xE7);
   emit_sse_operand(src, dst);
 }
 
 
 void Assembler::prefetch(const Operand& src, int level) {
   ASSERT(is_uint2(level));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x0F);
   EMIT(0x18);
   XMMRegister code = { level };  // Emit hint number in Reg position of RegR/M.
   emit_sse_operand(code, src);
 }
 
 
 void Assembler::movdbl(XMMRegister dst, const Operand& src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   movsd(dst, src);
 }
 
 
 void Assembler::movdbl(const Operand& dst, XMMRegister src) {
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   movsd(dst, src);
 }
 
 
 void Assembler::movsd(const Operand& dst, XMMRegister src ) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF2);  // double
   EMIT(0x0F);
   EMIT(0x11);  // store
   emit_sse_operand(src, dst);
 }
 
 
 void Assembler::movsd(XMMRegister dst, const Operand& src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF2);  // double
   EMIT(0x0F);
   EMIT(0x10);  // load
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::movsd(XMMRegister dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF2);
   EMIT(0x0F);
   EMIT(0x10);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::movss(const Operand& dst, XMMRegister src ) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF3);  // float
   EMIT(0x0F);
   EMIT(0x11);  // store
   emit_sse_operand(src, dst);
 }
 
 
 void Assembler::movss(XMMRegister dst, const Operand& src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF3);  // float
   EMIT(0x0F);
   EMIT(0x10);  // load
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::movss(XMMRegister dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0xF3);
   EMIT(0x0F);
   EMIT(0x10);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::movd(XMMRegister dst, const Operand& src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0x6E);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::movd(const Operand& dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0x7E);
   emit_sse_operand(src, dst);
 }
 
 
 void Assembler::pand(XMMRegister dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0xDB);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::pxor(XMMRegister dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0xEF);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::por(XMMRegister dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0xEB);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::ptest(XMMRegister dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE4_1));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0x38);
   EMIT(0x17);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::psllq(XMMRegister reg, int8_t shift) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0x73);
   emit_sse_operand(esi, reg);  // esi == 6
   EMIT(shift);
 }
 
 
 void Assembler::psllq(XMMRegister dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0xF3);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::psrlq(XMMRegister reg, int8_t shift) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0x73);
   emit_sse_operand(edx, reg);  // edx == 2
   EMIT(shift);
 }
 
 
 void Assembler::psrlq(XMMRegister dst, XMMRegister src) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0xD3);
   emit_sse_operand(dst, src);
 }
 
 
 void Assembler::pshufd(XMMRegister dst, XMMRegister src, int8_t shuffle) {
   ASSERT(CpuFeatures::IsEnabled(SSE2));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0x70);
   emit_sse_operand(dst, src);
   EMIT(shuffle);
 }
 
 
 void Assembler::pextrd(const Operand& dst, XMMRegister src, int8_t offset) {
   ASSERT(CpuFeatures::IsEnabled(SSE4_1));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0x3A);
   EMIT(0x16);
   emit_sse_operand(src, dst);
   EMIT(offset);
 }
 
 
 void Assembler::pinsrd(XMMRegister dst, const Operand& src, int8_t offset) {
   ASSERT(CpuFeatures::IsEnabled(SSE4_1));
   EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
   EMIT(0x66);
   EMIT(0x0F);
   EMIT(0x3A);
   EMIT(0x22);
   emit_sse_operand(dst, src);
   EMIT(offset);
 }
 
 
 void Assembler::emit_sse_operand(XMMRegister reg, const Operand& adr) {
@@ skipping 78 matching lines @@
   // Switch buffers.
   if (isolate()->assembler_spare_buffer() == NULL &&
       buffer_size_ == kMinimalBufferSize) {
     isolate()->set_assembler_spare_buffer(buffer_);
   } else {
     DeleteArray(buffer_);
   }
   buffer_ = desc.buffer;
   buffer_size_ = desc.buffer_size;
   pc_ += pc_delta;
-  if (last_pc_ != NULL) {
-    last_pc_ += pc_delta;
-  }
   reloc_info_writer.Reposition(reloc_info_writer.pos() + rc_delta,
                                reloc_info_writer.last_pc() + pc_delta);
 
   // Relocate runtime entries.
   for (RelocIterator it(desc); !it.done(); it.next()) {
     RelocInfo::Mode rmode = it.rinfo()->rmode();
     if (rmode == RelocInfo::RUNTIME_ENTRY) {
       int32_t* p = reinterpret_cast<int32_t*>(it.rinfo()->pc());
       *p -= pc_delta;  // relocate entry
     } else if (rmode == RelocInfo::INTERNAL_REFERENCE) {
@@ skipping 115 matching lines @@
     fprintf(coverage_log, "%s\n", file_line);
     fflush(coverage_log);
   }
 }
 
 #endif
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32