X87: [Atomics] code stubs for atomic operations.

src/x87/macro-assembler-x87.h

 // Copyright 2012 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.
 
 #ifndef V8_X87_MACRO_ASSEMBLER_X87_H_
 #define V8_X87_MACRO_ASSEMBLER_X87_H_
 
 #include "src/assembler.h"
 #include "src/bailout-reason.h"
 #include "src/frames.h"
@@ skipping 482 matching lines @@
     test(value, Immediate(kSmiTagMask));
     j(zero, smi_label, distance);
   }
   // Jump if register contain a non-smi.
   inline void JumpIfNotSmi(Register value, Label* not_smi_label,
                            Label::Distance distance = Label::kFar) {
     test(value, Immediate(kSmiTagMask));
     j(not_zero, not_smi_label, distance);
   }
 
+  // Jump if the value cannot be represented by a smi.
+  inline void JumpIfNotValidSmiValue(Register value, Register scratch,
+                                     Label* on_invalid,
+                                     Label::Distance distance = Label::kFar) {
+    mov(scratch, value);
+    add(scratch, Immediate(0x40000000U));
+    j(sign, on_invalid, distance);
+  }
+
+  // Jump if the unsigned integer value cannot be represented by a smi.
+  inline void JumpIfUIntNotValidSmiValue(
+      Register value, Label* on_invalid,
+      Label::Distance distance = Label::kFar) {
+    cmp(value, Immediate(0x40000000U));
+    j(above_equal, on_invalid, distance);
+  }
+
   void LoadInstanceDescriptors(Register map, Register descriptors);
   void EnumLength(Register dst, Register map);
   void NumberOfOwnDescriptors(Register dst, Register map);
   void LoadAccessor(Register dst, Register holder, int accessor_index,
                     AccessorComponent accessor);
 
   template<typename Field>
   void DecodeField(Register reg) {
     static const int shift = Field::kShift;
     static const int mask = Field::kMask >> Field::kShift;
@@ skipping 515 matching lines @@
   }                                                                       \
   masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_X87_MACRO_ASSEMBLER_X87_H_