Port r7868 (constant masking) to x64.

src/x64/macro-assembler-x64.cc

 // Copyright 2012 the V8 project authors. 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.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 874 matching lines @@
 
 void MacroAssembler::Set(const Operand& dst, int64_t x) {
   if (is_int32(x)) {
     movq(dst, Immediate(static_cast<int32_t>(x)));
   } else {
     Set(kScratchRegister, x);
     movq(dst, kScratchRegister);
   }
 }
 
+
+bool MacroAssembler::IsUnsafeInt(const int x) {
+  static const int kMaxBits = 17;
+  return !is_intn(x, kMaxBits);
+}
+
+
+void MacroAssembler::SafeMove(Register dst, Smi* src) {
+  ASSERT(!dst.is(kScratchRegister));
+  ASSERT(kSmiValueSize == 32);  // JIT cookie can be converted to Smi.
+  if (IsUnsafeInt(src->value()) && jit_cookie() != 0) {
+    Move(dst, Smi::FromInt(src->value() ^ jit_cookie()));
+    Move(kScratchRegister, Smi::FromInt(jit_cookie()));
+    xor_(dst, kScratchRegister);
+  } else {
+    Move(dst, src);
+  }
+}
+
+
+void MacroAssembler::SafePush(Smi* src) {
+  ASSERT(kSmiValueSize == 32);  // JIT cookie can be converted to Smi.
+  if (IsUnsafeInt(src->value()) && jit_cookie() != 0) {
+    Push(Smi::FromInt(src->value() ^ jit_cookie()));
+    Move(kScratchRegister, Smi::FromInt(jit_cookie()));
+    xor_(Operand(rsp, 0), kScratchRegister);
+  } else {
+    Push(src);
+  }
+}
+
+
 // ----------------------------------------------------------------------------
 // Smi tagging, untagging and tag detection.
 
 Register MacroAssembler::GetSmiConstant(Smi* source) {
   int value = source->value();
   if (value == 0) {
     xorl(kScratchRegister, kScratchRegister);
     return kScratchRegister;
   }
   if (value == 1) {
@@ skipping 3541 matching lines @@
   bind(&check_prototype);
   movq(rcx, FieldOperand(rbx, Map::kPrototypeOffset));
   cmpq(rcx, null_value);
   j(not_equal, &next);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64