Add MacroAssembler::Move(reg, immediate) on IA32.

BUG=
R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/188463003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19780 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/ia32/macro-assembler-ia32.cc

@@ -2833,6 +2833,15 @@ void MacroAssembler::Move(Register dst, Register src) {
 }
 
 
+void MacroAssembler::Move(Register dst, Immediate imm) {
+  if (imm.is_zero()) {
+    xor_(dst, dst);
+  } else {
+    mov(dst, imm);
+  }
+}
+
+
 void MacroAssembler::SetCounter(StatsCounter* counter, int value) {
   if (FLAG_native_code_counters && counter->Enabled()) {
     mov(Operand::StaticVariable(ExternalReference(counter)), Immediate(value));

src/ia32/macro-assembler-ia32.h

@@ -843,6 +843,9 @@ class MacroAssembler: public Assembler {
   // Move if the registers are not identical.
   void Move(Register target, Register source);
 
+  // Move a constant into a register using the most efficient encoding.
+  void Move(Register dst, Immediate imm);
+
   // Push a handle value.
   void Push(Handle<Object> handle) { push(Immediate(handle)); }
   void Push(Smi* smi) { Push(Handle<Smi>(smi, isolate())); }

test/cctest/test-macro-assembler-ia32.cc

@@ -122,6 +122,17 @@ TEST(LoadAndStoreWithRepresentation) {
   __ cmp(ebx, edx);
   __ j(not_equal, &exit);
 
+  // Test 5.
+  __ Move(edx, Immediate(0));  // Test Move()
+  __ cmp(edx, Immediate(0));
+  __ j(not_equal, &exit);
+  __ Move(ecx, Immediate(-1));
+  __ cmp(ecx, Immediate(-1));
+  __ j(not_equal, &exit);
+  __ Move(ebx, Immediate(0x77));
+  __ cmp(ebx, Immediate(0x77));
+  __ j(not_equal, &exit);
+
   __ xor_(eax, eax);  // Success.
   __ bind(&exit);
   __ add(esp, Immediate(1 * kPointerSize));