Assembler changes for enabling GrowHeap in Wasm

 - New RelocInfo mode WASM_MEMORY_REFERENCE as a marker for wasm code objects that need to be relocated on a heap change
 - RelocInfo mode recorded for immediates that use the memory buffer as base
 - Tests to verify address patching works

BUG=

Committed: https://crrev.com/cc815b69c17da368107ed77306a5bb161170c834
Cr-Commit-Position: refs/heads/master@{#34831}

Review URL: https://codereview.chromium.org/1759873002

Cr-Commit-Position: refs/heads/master@{#34836}

src/arm/assembler-arm-inl.h

@@ -71,6 +71,10 @@ Address RelocInfo::target_address() {
   return Assembler::target_address_at(pc_, host_);
 }
 
+Address RelocInfo::wasm_memory_reference() {
+  DCHECK(IsWasmMemoryReference(rmode_));
+  return Assembler::target_address_at(pc_, host_);
+}
 
 Address RelocInfo::target_address_address() {
   DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)
@@ -114,6 +118,18 @@ void RelocInfo::set_target_address(Address target,
   }
 }
 
+void RelocInfo::update_wasm_memory_reference(
+    Address old_base, Address new_base, size_t old_size, size_t new_size,
+    ICacheFlushMode icache_flush_mode) {
+  DCHECK(IsWasmMemoryReference(rmode_));
+  DCHECK(old_base <= wasm_memory_reference() &&
+         wasm_memory_reference() < old_base + old_size);
+  Address updated_reference = new_base + (wasm_memory_reference() - old_base);
+  DCHECK(new_base <= updated_reference &&
+         updated_reference < new_base + new_size);
+  Assembler::set_target_address_at(isolate_, pc_, host_, updated_reference,
+                                   icache_flush_mode);
+}
 
 Object* RelocInfo::target_object() {
   DCHECK(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);

src/arm64/assembler-arm64-inl.h

@@ -41,6 +41,18 @@ void RelocInfo::set_target_address(Address target,
   }
 }
 
+void RelocInfo::update_wasm_memory_reference(
+    Address old_base, Address new_base, size_t old_size, size_t new_size,
+    ICacheFlushMode icache_flush_mode) {
+  DCHECK(IsWasmMemoryReference(rmode_));
+  DCHECK(old_base <= wasm_memory_reference() &&
+         wasm_memory_reference() < old_base + old_size);
+  Address updated_reference = new_base + (wasm_memory_reference() - old_base);
+  DCHECK(new_base <= updated_reference &&
+         updated_reference < new_base + new_size);
+  Assembler::set_target_address_at(isolate_, pc_, host_, updated_reference,
+                                   icache_flush_mode);
+}
 
 inline int CPURegister::code() const {
   DCHECK(IsValid());
@@ -693,6 +705,10 @@ Address RelocInfo::target_address() {
   return Assembler::target_address_at(pc_, host_);
 }
 
+Address RelocInfo::wasm_memory_reference() {
+  DCHECK(IsWasmMemoryReference(rmode_));
+  return Assembler::target_address_at(pc_, host_);
+}
 
 Address RelocInfo::target_address_address() {
   DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)

src/arm64/assembler-arm64.cc

@@ -437,7 +437,8 @@ bool ConstPool::CanBeShared(RelocInfo::Mode mode) {
   DCHECK(mode != RelocInfo::NONE32);
 
   return RelocInfo::IsNone(mode) ||
-         (!assm_->serializer_enabled() && (mode >= RelocInfo::CELL));
+         (!assm_->serializer_enabled() &&
+          (mode >= RelocInfo::FIRST_SHAREABLE_RELOC_MODE));
 }
 
 

src/assembler.cc

@@ -842,6 +842,8 @@ const char* RelocInfo::RelocModeName(RelocInfo::Mode rmode) {
       return "code age sequence";
     case GENERATOR_CONTINUATION:
       return "generator continuation";
+    case WASM_MEMORY_REFERENCE:
+      return "wasm memory reference";
     case NUMBER_OF_MODES:
     case PC_JUMP:
       UNREACHABLE();
@@ -935,6 +937,7 @@ void RelocInfo::Verify(Isolate* isolate) {
     case DEBUG_BREAK_SLOT_AT_RETURN:
     case DEBUG_BREAK_SLOT_AT_CALL:
     case GENERATOR_CONTINUATION:
+    case WASM_MEMORY_REFERENCE:
     case NONE32:
     case NONE64:
       break;

src/assembler.h

@@ -385,6 +385,8 @@ class RelocInfo {
     DEBUGGER_STATEMENT,  // Code target for the debugger statement.
     EMBEDDED_OBJECT,
     CELL,
+    // To relocate pointers into the wasm memory embedded in wasm code
+    WASM_MEMORY_REFERENCE,
 
     // Everything after runtime_entry (inclusive) is not GC'ed.
     RUNTIME_ENTRY,
@@ -427,7 +429,8 @@ class RelocInfo {
     FIRST_REAL_RELOC_MODE = CODE_TARGET,
     LAST_REAL_RELOC_MODE = VENEER_POOL,
     LAST_CODE_ENUM = DEBUGGER_STATEMENT,
-    LAST_GCED_ENUM = CELL,
+    LAST_GCED_ENUM = WASM_MEMORY_REFERENCE,
+    FIRST_SHAREABLE_RELOC_MODE = CELL,
   };
 
   STATIC_ASSERT(NUMBER_OF_MODES <= kBitsPerInt);
@@ -511,6 +514,9 @@ class RelocInfo {
   static inline bool IsGeneratorContinuation(Mode mode) {
     return mode == GENERATOR_CONTINUATION;
   }
+  static inline bool IsWasmMemoryReference(Mode mode) {
+    return mode == WASM_MEMORY_REFERENCE;
+  }
   static inline int ModeMask(Mode mode) { return 1 << mode; }
 
   // Accessors
@@ -571,6 +577,10 @@ class RelocInfo {
                                 ICacheFlushMode icache_flush_mode =
                                     FLUSH_ICACHE_IF_NEEDED));
 
+  INLINE(Address wasm_memory_reference());
+  INLINE(void update_wasm_memory_reference(
+      Address old_base, Address new_base, size_t old_size, size_t new_size,
+      ICacheFlushMode icache_flush_mode = SKIP_ICACHE_FLUSH));
   // Returns the address of the constant pool entry where the target address
   // is held.  This should only be called if IsInConstantPool returns true.
   INLINE(Address constant_pool_entry_address());

src/ia32/assembler-ia32-inl.h

@@ -81,6 +81,10 @@ Address RelocInfo::target_address() {
   return Assembler::target_address_at(pc_, host_);
 }
 
+Address RelocInfo::wasm_memory_reference() {
+  DCHECK(IsWasmMemoryReference(rmode_));
+  return Memory::Address_at(pc_);
+}
 
 Address RelocInfo::target_address_address() {
   DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)
@@ -115,6 +119,20 @@ void RelocInfo::set_target_address(Address target,
   }
 }
 
+void RelocInfo::update_wasm_memory_reference(
+    Address old_base, Address new_base, size_t old_size, size_t new_size,
+    ICacheFlushMode icache_flush_mode) {
+  DCHECK(IsWasmMemoryReference(rmode_));
+  DCHECK(old_base <= wasm_memory_reference() &&
+         wasm_memory_reference() < old_base + old_size);
+  Address updated_reference = new_base + (wasm_memory_reference() - old_base);
+  DCHECK(new_base <= updated_reference &&
+         updated_reference < new_base + new_size);
+  Memory::Address_at(pc_) = updated_reference;
+  if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
+    Assembler::FlushICache(isolate_, pc_, sizeof(int32_t));
+  }
+}
 
 Object* RelocInfo::target_object() {
   DCHECK(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
@@ -321,6 +339,10 @@ Immediate::Immediate(int x)  {
   rmode_ = RelocInfo::NONE32;
 }
 
+Immediate::Immediate(Address x, RelocInfo::Mode rmode) {
+  x_ = reinterpret_cast<int32_t>(x);
+  rmode_ = rmode;
+}
 
 Immediate::Immediate(const ExternalReference& ext) {
   x_ = reinterpret_cast<int32_t>(ext.address());

src/ia32/assembler-ia32.h

@@ -271,6 +271,7 @@ class Immediate BASE_EMBEDDED {
   inline explicit Immediate(Handle<Object> handle);
   inline explicit Immediate(Smi* value);
   inline explicit Immediate(Address addr);
+  inline explicit Immediate(Address x, RelocInfo::Mode rmode);
 
   static Immediate CodeRelativeOffset(Label* label) {
     return Immediate(label);

src/mips/assembler-mips-inl.h

@@ -102,6 +102,10 @@ Address RelocInfo::target_address() {
   return Assembler::target_address_at(pc_, host_);
 }
 
+Address RelocInfo::wasm_memory_reference() {
+  DCHECK(IsWasmMemoryReference(rmode_));
+  return Assembler::target_address_at(pc_, host_);
+}
 
 Address RelocInfo::target_address_address() {
   DCHECK(IsCodeTarget(rmode_) ||
@@ -152,6 +156,18 @@ void RelocInfo::set_target_address(Address target,
   }
 }
 
+void RelocInfo::update_wasm_memory_reference(
+    Address old_base, Address new_base, size_t old_size, size_t new_size,
+    ICacheFlushMode icache_flush_mode) {
+  DCHECK(IsWasmMemoryReference(rmode_));
+  DCHECK(old_base <= wasm_memory_reference() &&
+         wasm_memory_reference() < old_base + old_size);
+  Address updated_reference = new_base + (wasm_memory_reference() - old_base);
+  DCHECK(new_base <= updated_reference &&
+         updated_reference < new_base + new_size);
+  Assembler::set_target_address_at(isolate_, pc_, host_, updated_reference,
+                                   icache_flush_mode);
+}
 
 Address Assembler::target_address_from_return_address(Address pc) {
   return pc - kCallTargetAddressOffset;

src/mips64/assembler-mips64-inl.h

@@ -102,6 +102,10 @@ Address RelocInfo::target_address() {
   return Assembler::target_address_at(pc_, host_);
 }
 
+Address RelocInfo::wasm_memory_reference() {
+  DCHECK(IsWasmMemoryReference(rmode_));
+  return Assembler::target_address_at(pc_, host_);
+}
 
 Address RelocInfo::target_address_address() {
   DCHECK(IsCodeTarget(rmode_) ||
@@ -154,6 +158,18 @@ void RelocInfo::set_target_address(Address target,
   }
 }
 
+void RelocInfo::update_wasm_memory_reference(
+    Address old_base, Address new_base, size_t old_size, size_t new_size,
+    ICacheFlushMode icache_flush_mode) {
+  DCHECK(IsWasmMemoryReference(rmode_));
+  DCHECK(old_base <= wasm_memory_reference() &&
+         wasm_memory_reference() < old_base + old_size);
+  Address updated_reference = new_base + (wasm_memory_reference() - old_base);
+  DCHECK(new_base <= updated_reference &&
+         updated_reference < new_base + new_size);
+  Assembler::set_target_address_at(isolate_, pc_, host_, updated_reference,
+                                   icache_flush_mode);
+}
 
 Address Assembler::target_address_from_return_address(Address pc) {
   return pc - kCallTargetAddressOffset;

src/x64/assembler-x64-inl.h

@@ -326,6 +326,10 @@ Address RelocInfo::target_address() {
   return Assembler::target_address_at(pc_, host_);
 }
 
+Address RelocInfo::wasm_memory_reference() {
+  DCHECK(IsWasmMemoryReference(rmode_));
+  return Memory::Address_at(pc_);
+}
 
 Address RelocInfo::target_address_address() {
   DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)
@@ -364,6 +368,20 @@ void RelocInfo::set_target_address(Address target,
   }
 }
 
+void RelocInfo::update_wasm_memory_reference(
+    Address old_base, Address new_base, size_t old_size, size_t new_size,
+    ICacheFlushMode icache_flush_mode) {
+  DCHECK(IsWasmMemoryReference(rmode_));
+  DCHECK(old_base <= wasm_memory_reference() &&
+         wasm_memory_reference() < old_base + old_size);
+  Address updated_reference = new_base + (wasm_memory_reference() - old_base);
+  DCHECK(new_base <= updated_reference &&
+         updated_reference < new_base + new_size);
+  Memory::Address_at(pc_) = updated_reference;
+  if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
+    Assembler::FlushICache(isolate_, pc_, sizeof(int64_t));
+  }
+}
 
 Object* RelocInfo::target_object() {
   DCHECK(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);

src/x64/assembler-x64.cc

@@ -1469,17 +1469,18 @@ void Assembler::movp(Register dst, void* value, RelocInfo::Mode rmode) {
   emitp(value, rmode);
 }
 
-
-void Assembler::movq(Register dst, int64_t value) {
+void Assembler::movq(Register dst, int64_t value, RelocInfo::Mode rmode) {
   EnsureSpace ensure_space(this);
   emit_rex_64(dst);
   emit(0xB8 | dst.low_bits());
+  if (!RelocInfo::IsNone(rmode)) {
+    RecordRelocInfo(rmode, value);
+  }
   emitq(value);
 }
 
-
-void Assembler::movq(Register dst, uint64_t value) {
-  movq(dst, static_cast<int64_t>(value));
+void Assembler::movq(Register dst, uint64_t value, RelocInfo::Mode rmode) {
+  movq(dst, static_cast<int64_t>(value), rmode);
 }
 
 

src/x64/assembler-x64.h

@@ -699,8 +699,10 @@ class Assembler : public AssemblerBase {
   void movp(Register dst, void* ptr, RelocInfo::Mode rmode);
 
   // Loads a 64-bit immediate into a register.
-  void movq(Register dst, int64_t value);
-  void movq(Register dst, uint64_t value);
+  void movq(Register dst, int64_t value,
+            RelocInfo::Mode rmode = RelocInfo::NONE64);
+  void movq(Register dst, uint64_t value,
+            RelocInfo::Mode rmode = RelocInfo::NONE64);
 
   void movsxbl(Register dst, Register src);
   void movsxbl(Register dst, const Operand& src);

src/x64/macro-assembler-x64.cc

@@ -1114,6 +1114,14 @@ void MacroAssembler::Set(Register dst, int64_t x) {
   }
 }
 
+void MacroAssembler::Set(Register dst, int64_t x, RelocInfo::Mode rmode) {
+  if (rmode == RelocInfo::WASM_MEMORY_REFERENCE) {
+    DCHECK(x != 0);
+    movq(dst, x, rmode);
+  } else {
+    DCHECK(RelocInfo::IsNone(rmode));
+  }
+}
 
 void MacroAssembler::Set(const Operand& dst, intptr_t x) {
   if (kPointerSize == kInt64Size) {

src/x64/macro-assembler-x64.h

@@ -818,6 +818,7 @@ class MacroAssembler: public Assembler {
 
   // Load a register with a long value as efficiently as possible.
   void Set(Register dst, int64_t x);
+  void Set(Register dst, int64_t x, RelocInfo::Mode rmode);
   void Set(const Operand& dst, intptr_t x);
 
   void Cvtss2sd(XMMRegister dst, XMMRegister src);

test/cctest/cctest.gyp

@@ -202,7 +202,8 @@
             'test-code-stubs-ia32.cc',
             'test-disasm-ia32.cc',
             'test-macro-assembler-ia32.cc',
-            'test-log-stack-tracer.cc'
+            'test-log-stack-tracer.cc',
+            'test-run-wasm-relocation-ia32.cc'
           ],
         }],
         ['v8_target_arch=="x64"', {
@@ -212,7 +213,8 @@
             'test-code-stubs-x64.cc',
             'test-disasm-x64.cc',
             'test-macro-assembler-x64.cc',
-            'test-log-stack-tracer.cc'
+            'test-log-stack-tracer.cc',
+            'test-run-wasm-relocation-x64.cc'
           ],
         }],
         ['v8_target_arch=="arm"', {
@@ -221,7 +223,8 @@
             'test-code-stubs.cc',
             'test-code-stubs-arm.cc',
             'test-disasm-arm.cc',
-            'test-macro-assembler-arm.cc'
+            'test-macro-assembler-arm.cc',
+            'test-run-wasm-relocation-arm.cc'
           ],
         }],
         ['v8_target_arch=="arm64"', {
@@ -233,7 +236,8 @@
             'test-disasm-arm64.cc',
             'test-fuzz-arm64.cc',
             'test-javascript-arm64.cc',
-            'test-js-arm64-variables.cc'
+            'test-js-arm64-variables.cc',
+            'test-run-wasm-relocation-arm64.cc'
           ],
         }],
         ['v8_target_arch=="s390"', {

test/cctest/test-run-wasm-relocation-arm.cc

+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <iostream>  // NOLINT(readability/streams)
+
+#include "src/v8.h"
+#include "test/cctest/cctest.h"
+
+#include "src/arm/assembler-arm-inl.h"
+#include "src/arm/simulator-arm.h"
+#include "src/disassembler.h"
+#include "src/factory.h"
+#include "src/ostreams.h"
+#include "test/cctest/compiler/c-signature.h"
+#include "test/cctest/compiler/call-tester.h"
+
+using namespace v8::base;
+using namespace v8::internal;
+using namespace v8::internal::compiler;
+
+#define __ assm.
+
+static int32_t DummyStaticFunction(Object* result) { return 1; }
+
+TEST(WasmRelocationArm) {
+  CcTest::InitializeVM();
+  Isolate* isolate = CcTest::i_isolate();
+  HandleScope scope(isolate);
+  v8::internal::byte buffer[4096];
+  DummyStaticFunction(NULL);
+  int32_t imm = 1234567;
+
+  Assembler assm(isolate, buffer, sizeof buffer);
+
+  __ mov(r0, Operand(imm, RelocInfo::WASM_MEMORY_REFERENCE));
+  __ mov(pc, Operand(lr));
+
+  CodeDesc desc;
+  assm.GetCode(&desc);
+  Handle<Code> code = isolate->factory()->NewCode(
+      desc, Code::ComputeFlags(Code::STUB), Handle<Code>());
+
+  CSignature0<int32_t> csig;
+  CodeRunner<int32_t> runnable(isolate, code, &csig);
+  int32_t ret_value = runnable.Call();
+  CHECK_EQ(ret_value, imm);
+
+#ifdef DEBUG
+  OFStream os(stdout);
+  code->Print(os);
+  ::printf("f() = %d\n\n", ret_value);
+#endif
+  size_t offset = 1234;
+
+  // Relocating references by offset
+  int mode_mask = (1 << RelocInfo::WASM_MEMORY_REFERENCE);
+  for (RelocIterator it(*code, mode_mask); !it.done(); it.next()) {
+    RelocInfo::Mode mode = it.rinfo()->rmode();
+    if (RelocInfo::IsWasmMemoryReference(mode)) {
+      // Dummy values of size used here as the objective of the test is to
+      // verify that the immediate is patched correctly
+      it.rinfo()->update_wasm_memory_reference(
+          it.rinfo()->wasm_memory_reference(),
+          it.rinfo()->wasm_memory_reference() + offset, 1, 2,
+          SKIP_ICACHE_FLUSH);
+    }
+  }
+
+  // Call into relocated code object
+  ret_value = runnable.Call();
+  CHECK_EQ((imm + offset), ret_value);
+
+#ifdef DEBUG
+  code->Print(os);
+  ::printf("f() = %d\n\n", ret_value);
+#endif
+}
+
+#undef __

test/cctest/test-run-wasm-relocation-arm64.cc

+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <iostream>  // NOLINT(readability/streams)
+
+#include "src/v8.h"
+#include "test/cctest/cctest.h"
+
+#include "src/arm64/simulator-arm64.h"
+#include "src/arm64/utils-arm64.h"
+#include "src/disassembler.h"
+#include "src/factory.h"
+#include "src/macro-assembler.h"
+#include "src/ostreams.h"
+#include "test/cctest/compiler/c-signature.h"
+#include "test/cctest/compiler/call-tester.h"
+
+using namespace v8::base;
+using namespace v8::internal;
+using namespace v8::internal::compiler;
+
+#define __ masm.
+
+static int64_t DummyStaticFunction(Object* result) { return 1; }
+
+TEST(WasmRelocationArm64) {
+  CcTest::InitializeVM();
+  Isolate* isolate = CcTest::i_isolate();
+  HandleScope scope(isolate);
+  v8::internal::byte buffer[4096];
+  DummyStaticFunction(NULL);
+  int64_t imm = 1234567;
+
+  MacroAssembler masm(isolate, buffer, sizeof buffer,
+                      v8::internal::CodeObjectRequired::kYes);
+
+  __ Mov(x0, Immediate(imm, RelocInfo::WASM_MEMORY_REFERENCE));
+  __ Ret();
+
+  CodeDesc desc;
+  masm.GetCode(&desc);
+  Handle<Code> code = isolate->factory()->NewCode(
+      desc, Code::ComputeFlags(Code::STUB), Handle<Code>());
+
+  CSignature0<int64_t> csig;
+  CodeRunner<int64_t> runnable(isolate, code, &csig);
+  int64_t ret_value = runnable.Call();
+  CHECK_EQ(ret_value, imm);
+
+#ifdef DEBUG
+  OFStream os(stdout);
+  code->Print(os);
+  ::printf("f() = %ld\n\n", ret_value);
+#endif
+  size_t offset = 1234;
+
+  // Relocating reference by offset
+  int mode_mask = (1 << RelocInfo::WASM_MEMORY_REFERENCE);
+  for (RelocIterator it(*code, mode_mask); !it.done(); it.next()) {
+    RelocInfo::Mode mode = it.rinfo()->rmode();
+    if (RelocInfo::IsWasmMemoryReference(mode)) {
+      // Dummy values of size used here as the objective of the test is to
+      // verify that the immediate is patched correctly
+      it.rinfo()->update_wasm_memory_reference(
+          it.rinfo()->wasm_memory_reference(),
+          it.rinfo()->wasm_memory_reference() + offset, 1, 2,
+          SKIP_ICACHE_FLUSH);
+    }
+  }
+
+  // Call into relocated code object
+  ret_value = runnable.Call();
+  CHECK_EQ((imm + offset), ret_value);
+
+#ifdef DEBUG
+  code->Print(os);
+  ::printf("f() = %ld\n\n", ret_value);
+#endif
+}
+
+#undef __

test/cctest/test-run-wasm-relocation-ia32.cc

+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <stdlib.h>
+
+#include "src/v8.h"
+
+#include "src/debug/debug.h"
+#include "src/disasm.h"
+#include "src/disassembler.h"
+#include "src/ia32/frames-ia32.h"
+#include "src/ic/ic.h"
+#include "src/macro-assembler.h"
+#include "test/cctest/cctest.h"
+#include "test/cctest/compiler/c-signature.h"
+#include "test/cctest/compiler/call-tester.h"
+
+using namespace v8::internal;
+using namespace v8::internal::compiler;
+
+#define __ assm.
+
+static int32_t DummyStaticFunction(Object* result) { return 1; }
+
+TEST(WasmRelocationIa32) {
+  CcTest::InitializeVM();
+  Zone zone;
+  Isolate* isolate = CcTest::i_isolate();
+  HandleScope scope(isolate);
+  v8::internal::byte buffer[4096];
+  Assembler assm(isolate, buffer, sizeof buffer);
+  DummyStaticFunction(NULL);
+  int32_t imm = 1234567;
+
+  __ mov(eax, Immediate(reinterpret_cast<Address>(imm),
+                        RelocInfo::WASM_MEMORY_REFERENCE));
+  __ nop();
+  __ ret(0);
+
+  CSignature0<int32_t> csig;
+  CodeDesc desc;
+  assm.GetCode(&desc);
+  Handle<Code> code = isolate->factory()->NewCode(
+      desc, Code::ComputeFlags(Code::STUB), Handle<Code>());
+  USE(code);
+
+  CodeRunner<int32_t> runnable(isolate, code, &csig);
+  int32_t ret_value = runnable.Call();
+  CHECK_EQ(ret_value, imm);
+
+#ifdef OBJECT_PRINT
+  OFStream os(stdout);
+  code->Print(os);
+  byte* begin = code->instruction_start();
+  byte* end = begin + code->instruction_size();
+  disasm::Disassembler::Disassemble(stdout, begin, end);
+#endif
+
+  size_t offset = 1234;
+
+  // Relocating references by offset
+  int mode_mask = (1 << RelocInfo::WASM_MEMORY_REFERENCE);
+  for (RelocIterator it(*code, mode_mask); !it.done(); it.next()) {
+    RelocInfo::Mode mode = it.rinfo()->rmode();
+    if (RelocInfo::IsWasmMemoryReference(mode)) {
+      // Dummy values of size used here as the objective of the test is to
+      // verify that the immediate is patched correctly
+      it.rinfo()->update_wasm_memory_reference(
+          it.rinfo()->wasm_memory_reference(),
+          it.rinfo()->wasm_memory_reference() + offset, 1, 2,
+          SKIP_ICACHE_FLUSH);
+    }
+  }
+
+  // Check if immediate is updated correctly
+  ret_value = runnable.Call();
+  CHECK_EQ(ret_value, imm + offset);
+
+#ifdef OBJECT_PRINT
+  // OFStream os(stdout);
+  code->Print(os);
+  begin = code->instruction_start();
+  end = begin + code->instruction_size();
+  disasm::Disassembler::Disassemble(stdout, begin, end);
+#endif
+}
+
+#undef __

test/cctest/test-run-wasm-relocation-x64.cc

+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <stdlib.h>
+
+#include "src/v8.h"
+
+#include "src/debug/debug.h"
+#include "src/disasm.h"
+#include "src/disassembler.h"
+#include "src/ic/ic.h"
+#include "src/macro-assembler.h"
+#include "test/cctest/cctest.h"
+#include "test/cctest/compiler/c-signature.h"
+#include "test/cctest/compiler/call-tester.h"
+
+using namespace v8::internal;
+using namespace v8::internal::compiler;
+
+#define __ assm.
+
+static int32_t DummyStaticFunction(Object* result) { return 1; }
+TEST(WasmRelocationX64movq64) {
+  CcTest::InitializeVM();
+  Isolate* isolate = CcTest::i_isolate();
+  HandleScope scope(isolate);
+  v8::internal::byte buffer[4096];
+  Assembler assm(isolate, buffer, sizeof buffer);
+  DummyStaticFunction(NULL);
+  int64_t imm = 1234567;
+
+  __ movq(rax, imm, RelocInfo::WASM_MEMORY_REFERENCE);
+  __ nop();
+  __ ret(0);
+
+  CodeDesc desc;
+  assm.GetCode(&desc);
+  Handle<Code> code = isolate->factory()->NewCode(
+      desc, Code::ComputeFlags(Code::STUB), Handle<Code>());
+  USE(code);
+
+  CSignature0<int64_t> csig;
+  CodeRunner<int64_t> runnable(isolate, code, &csig);
+  int64_t ret_value = runnable.Call();
+  CHECK_EQ(ret_value, imm);
+
+#ifdef OBJECT_PRINT
+  OFStream os(stdout);
+  code->Print(os);
+  byte* begin = code->instruction_start();
+  byte* end = begin + code->instruction_size();
+  disasm::Disassembler::Disassemble(stdout, begin, end);
+#endif
+  size_t offset = 1234;
+
+  // Relocating references by offset
+  int mode_mask = (1 << RelocInfo::WASM_MEMORY_REFERENCE);
+  for (RelocIterator it(*code, mode_mask); !it.done(); it.next()) {
+    RelocInfo::Mode mode = it.rinfo()->rmode();
+    if (RelocInfo::IsWasmMemoryReference(mode)) {
+      // Dummy values of size used here as the objective of the test is to
+      // verify that the immediate is patched correctly
+      it.rinfo()->update_wasm_memory_reference(
+          it.rinfo()->wasm_memory_reference(),
+          it.rinfo()->wasm_memory_reference() + offset, 1, 2,
+          SKIP_ICACHE_FLUSH);
+    }
+  }
+
+  // Check if immediate is updated correctly
+  ret_value = runnable.Call();
+  CHECK_EQ(ret_value, imm + offset);
+
+#ifdef OBJECT_PRINT
+  code->Print(os);
+  begin = code->instruction_start();
+  end = begin + code->instruction_size();
+  disasm::Disassembler::Disassemble(stdout, begin, end);
+#endif
+}
+
+#undef __