Land Ivan's change of 'Remove support for verified memory handling'

runtime/vm/assembler_ia32.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // NOLINT
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/cpu.h"
 #include "vm/heap.h"
 #include "vm/instructions.h"
 #include "vm/memory_region.h"
 #include "vm/runtime_entry.h"
 #include "vm/stack_frame.h"
 #include "vm/stub_code.h"
-#include "vm/verified_memory.h"
 
 namespace dart {
 
 DECLARE_FLAG(bool, inline_alloc);
 
 
 class DirectCallRelocation : public AssemblerFixup {
  public:
   void Process(const MemoryRegion& region, intptr_t position) {
     // Direct calls are relative to the following instruction on x86.
@@ skipping 1963 matching lines @@
 
 
 void Assembler::hlt() {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   EmitUint8(0xF4);
 }
 
 
 void Assembler::j(Condition condition, Label* label, bool near) {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
-  if (VerifiedMemory::enabled()) {
-    near = Assembler::kFarJump;
-  }
   if (label->IsBound()) {
     static const int kShortSize = 2;
     static const int kLongSize = 6;
     intptr_t offset = label->Position() - buffer_.Size();
     ASSERT(offset <= 0);
     if (Utils::IsInt(8, offset - kShortSize)) {
       EmitUint8(0x70 + condition);
       EmitUint8((offset - kShortSize) & 0xFF);
     } else {
       EmitUint8(0x0F);
@@ skipping 22 matching lines @@
 
 void Assembler::jmp(Register reg) {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   EmitUint8(0xFF);
   EmitRegisterOperand(4, reg);
 }
 
 
 void Assembler::jmp(Label* label, bool near) {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
-  if (VerifiedMemory::enabled()) {
-    near = Assembler::kFarJump;
-  }
   if (label->IsBound()) {
     static const int kShortSize = 2;
     static const int kLongSize = 5;
     intptr_t offset = label->Position() - buffer_.Size();
     ASSERT(offset <= 0);
     if (Utils::IsInt(8, offset - kShortSize)) {
       EmitUint8(0xEB);
       EmitUint8((offset - kShortSize) & 0xFF);
     } else {
       EmitUint8(0xE9);
@@ skipping 200 matching lines @@
   // Mask out higher, uninteresting bits which were polluted by dest.
   andl(value, Immediate(kObjectAlignment - 1));
   // Compare with the expected bit pattern.
   cmpl(value, Immediate(
       (kNewObjectAlignmentOffset >> 1) + kHeapObjectTag +
       kOldObjectAlignmentOffset + kHeapObjectTag));
   j(NOT_ZERO, no_update, Assembler::kNearJump);
 }
 
 
-void Assembler::VerifyHeapWord(const Address& address,
-                               FieldContent old_content) {
-#if defined(DEBUG)
-  switch (old_content) {
-    case kEmptyOrSmiOrNull:
-      VerifyUninitialized(address);
-      break;
-    case kHeapObjectOrSmi:
-      VerifyObjectOrSmi(address);
-      break;
-    case kOnlySmi:
-      VerifySmi(address);
-      break;
-  }
-#endif  // DEBUG
-  if (VerifiedMemory::enabled()) {
-    Register addr_reg = EDX;
-    Register value = EBX;
-    // Preserve registers.
-    pushl(addr_reg);
-    pushl(value);
-    leal(addr_reg, address);
-    // ASSERT(*address == *(address + offset))
-    movl(value, Address(addr_reg, 0));
-    cmpl(value, Address(addr_reg, VerifiedMemory::offset()));
-    Label ok;
-    j(EQUAL, &ok, Assembler::kNearJump);
-    Stop("Write barrier verification failed");
-    Bind(&ok);
-    popl(value);
-    popl(addr_reg);
-  }
-}
-
-
-void Assembler::VerifiedWrite(const Address& dest,
-                              Register value,
-                              FieldContent old_content) {
-  VerifyHeapWord(dest, old_content);
-  movl(dest, value);
-  if (VerifiedMemory::enabled()) {
-    Register temp = (value == EDX) ? ECX : EDX;
-    pushl(temp);
-    leal(temp, dest);
-    movl(Address(temp, VerifiedMemory::offset()), value);
-    popl(temp);
-  }
-}
-
-
-#if defined(DEBUG)
-void Assembler::VerifyObjectOrSmi(const Address& dest) {
-  Label ok;
-  testb(dest, Immediate(kHeapObjectTag));
-  j(ZERO, &ok, Assembler::kNearJump);
-  // Non-smi case: Verify object pointer is word-aligned when untagged.
-  COMPILE_ASSERT(kHeapObjectTag == 1);
-  testb(dest, Immediate((kWordSize - 1) - kHeapObjectTag));
-  j(ZERO, &ok, Assembler::kNearJump);
-  Stop("Expected heap object or Smi");
-  Bind(&ok);
-}
-
-
-void Assembler::VerifyUninitialized(const Address& dest) {
-  Label ok;
-  testb(dest, Immediate(kHeapObjectTag));
-  j(ZERO, &ok, Assembler::kNearJump);
-  // Non-smi case: Check for the special zap word or null.
-#if defined(DEBUG)
-  cmpl(dest, Immediate(Heap::kZap32Bits));
-  j(EQUAL, &ok, Assembler::kNearJump);
-#else
-#error Only supported in DEBUG mode
-#endif
-  cmpl(dest, Immediate(reinterpret_cast<uint32_t>(Object::null())));
-  j(EQUAL, &ok, Assembler::kNearJump);
-  Stop("Expected zapped, Smi or null");
-  Bind(&ok);
-}
-
-
-void Assembler::VerifySmi(const Address& dest, const char* stop_msg) {
-  Label done;
-  testb(dest, Immediate(kHeapObjectTag));
-  j(ZERO, &done, Assembler::kNearJump);
-  Stop(stop_msg);
-  Bind(&done);
-}
-#endif  // defined(DEBUG)
-
-
 // Destroys the value register.
 void Assembler::StoreIntoObject(Register object,
                                 const Address& dest,
                                 Register value,
                                 bool can_value_be_smi) {
   ASSERT(object != value);
-  VerifiedWrite(dest, value, kHeapObjectOrSmi);
+  movl(dest, value);
   Label done;
   if (can_value_be_smi) {
     StoreIntoObjectFilter(object, value, &done);
   } else {
     StoreIntoObjectFilterNoSmi(object, value, &done);
   }
   // A store buffer update is required.
   if (value != EDX) {
     pushl(EDX);  // Preserve EDX.
   }
   if (object != EDX) {
     movl(EDX, object);
   }
   call(Address(THR, Thread::update_store_buffer_entry_point_offset()));
   if (value != EDX) {
     popl(EDX);  // Restore EDX.
   }
   Bind(&done);
 }
 
 
 void Assembler::StoreIntoObjectNoBarrier(Register object,
                                          const Address& dest,
-                                         Register value,
-                                         FieldContent old_content) {
-  VerifiedWrite(dest, value, old_content);
+                                         Register value) {
+  movl(dest, value);
 #if defined(DEBUG)
   Label done;
   pushl(value);
   StoreIntoObjectFilter(object, value, &done);
   Stop("Store buffer update is required");
   Bind(&done);
   popl(value);
 #endif  // defined(DEBUG)
   // No store buffer update.
 }
 
 
 void Assembler::UnverifiedStoreOldObject(const Address& dest,
                                          const Object& value) {
   ASSERT(!value.IsICData() || ICData::Cast(value).IsOriginal());
   ASSERT(!value.IsField() || Field::Cast(value).IsOriginal());
   ASSERT(value.IsOld());
   ASSERT(!value.InVMHeap());
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   EmitUint8(0xC7);
   EmitOperand(0, dest);
   buffer_.EmitObject(value);
 }
 
 
 void Assembler::StoreIntoObjectNoBarrier(Register object,
                                          const Address& dest,
-                                         const Object& value,
-                                         FieldContent old_content) {
+                                         const Object& value) {
   ASSERT(!value.IsICData() || ICData::Cast(value).IsOriginal());
   ASSERT(!value.IsField() || Field::Cast(value).IsOriginal());
-  VerifyHeapWord(dest, old_content);
   if (value.IsSmi() || value.InVMHeap()) {
     Immediate imm_value(reinterpret_cast<int32_t>(value.raw()));
     movl(dest, imm_value);
-    if (VerifiedMemory::enabled()) {
-      Register temp = ECX;
-      pushl(temp);
-      leal(temp, dest);
-      movl(Address(temp, VerifiedMemory::offset()), imm_value);
-      popl(temp);
-    }
   } else {
     UnverifiedStoreOldObject(dest, value);
-    if (VerifiedMemory::enabled()) {
-      Register temp = EDX;
-      pushl(temp);
-      leal(temp, dest);
-      UnverifiedStoreOldObject(Address(temp, VerifiedMemory::offset()), value);
-      popl(temp);
-    }
   }
   // No store buffer update.
 }
 
 
 void Assembler::StoreIntoSmiField(const Address& dest, Register value) {
 #if defined(DEBUG)
   Label done;
   testl(value, Immediate(kHeapObjectTag));
   j(ZERO, &done);
   Stop("New value must be Smi.");
   Bind(&done);
 #endif  // defined(DEBUG)
-  VerifiedWrite(dest, value, kOnlySmi);
+  movl(dest, value);
 }
 
 
 void Assembler::ZeroInitSmiField(const Address& dest) {
-  VerifyHeapWord(dest, kEmptyOrSmiOrNull);
   Immediate zero(Smi::RawValue(0));
   movl(dest, zero);
-  if (VerifiedMemory::enabled()) {
-    Register temp = ECX;
-    pushl(temp);
-    leal(temp, dest);
-    movl(Address(temp, VerifiedMemory::offset()), zero);
-    popl(temp);
-  }
 }
 
 
 void Assembler::IncrementSmiField(const Address& dest, int32_t increment) {
   // Note: FlowGraphCompiler::EdgeCounterIncrementSizeInBytes depends on
   // the length of this instruction sequence.
-  VerifyHeapWord(dest, kOnlySmi);
   Immediate inc_imm(Smi::RawValue(increment));
   addl(dest, inc_imm);
-  if (VerifiedMemory::enabled()) {
-    Register temp = ECX;
-    pushl(temp);
-    leal(temp, dest);
-    addl(Address(temp, VerifiedMemory::offset()), inc_imm);
-    popl(temp);
-  }
 }
 
 
 void Assembler::LoadDoubleConstant(XmmRegister dst, double value) {
   // TODO(5410843): Need to have a code constants table.
   int64_t constant = bit_cast<int64_t, double>(value);
   pushl(Immediate(Utils::High32Bits(constant)));
   pushl(Immediate(Utils::Low32Bits(constant)));
   movsd(dst, Address(ESP, 0));
   addl(ESP, Immediate(2 * kWordSize));
@@ skipping 681 matching lines @@
 
 const char* Assembler::FpuRegisterName(FpuRegister reg) {
   ASSERT((0 <= reg) && (reg < kNumberOfXmmRegisters));
   return xmm_reg_names[reg];
 }
 
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32