MIPS: Don't explicitly pass requested representations to constants; implement ConstantS

Port r14874 (e93cc94e)

BUG=

Review URL: https://codereview.chromium.org/15731008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14890 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/lithium-codegen-mips.cc

@@ -1500,7 +1500,11 @@ void LCodeGen::DoSubI(LSubI* instr) {
 
 
 void LCodeGen::DoConstantI(LConstantI* instr) {
-  ASSERT(instr->result()->IsRegister());
+  __ li(ToRegister(instr->result()), Operand(instr->value()));
+}
+
+
+void LCodeGen::DoConstantS(LConstantS* instr) {
   __ li(ToRegister(instr->result()), Operand(instr->value()));
 }
 

src/mips/lithium-mips.cc

@@ -1927,11 +1927,13 @@ LInstruction* LChunkBuilder::DoReturn(HReturn* instr) {
 
 LInstruction* LChunkBuilder::DoConstant(HConstant* instr) {
   Representation r = instr->representation();
-  if (r.IsInteger32()) {
+  if (r.IsSmi()) {
+    return DefineAsRegister(new(zone()) LConstantS);
+  } else if (r.IsInteger32()) {
     return DefineAsRegister(new(zone()) LConstantI);
   } else if (r.IsDouble()) {
     return DefineAsRegister(new(zone()) LConstantD);
-  } else if (r.IsSmiOrTagged()) {
+  } else if (r.IsTagged()) {
     return DefineAsRegister(new(zone()) LConstantT);
   } else {
     UNREACHABLE();

src/mips/lithium-mips.h

@@ -87,6 +87,7 @@ class LCodeGen;
   V(CmpT)                                       \
   V(ConstantD)                                  \
   V(ConstantI)                                  \
+  V(ConstantS)                                  \
   V(ConstantT)                                  \
   V(Context)                                    \
   V(DebugBreak)                                 \
@@ -1153,6 +1154,15 @@ class LConstantI: public LTemplateInstruction<1, 0, 0> {
 };
 
 
+class LConstantS: public LTemplateInstruction<1, 0, 0> {
+ public:
+  DECLARE_CONCRETE_INSTRUCTION(ConstantS, "constant-s")
+  DECLARE_HYDROGEN_ACCESSOR(Constant)
+
+  Smi* value() const { return Smi::FromInt(hydrogen()->Integer32Value()); }
+};
+
+
 class LConstantD: public LTemplateInstruction<1, 0, 0> {
  public:
   DECLARE_CONCRETE_INSTRUCTION(ConstantD, "constant-d")