MIPS: Implement HChange support for Smis and use it in Load/StoreNameField

src/mips/lithium-mips.cc

Index: src/mips/lithium-mips.cc
diff --git a/src/mips/lithium-mips.cc b/src/mips/lithium-mips.cc
index 04125d1696d11eb40138281f9d81d3336701c572..758112cba6ee549ecec2df2a7526704985d38c6f 100644
--- a/src/mips/lithium-mips.cc
+++ b/src/mips/lithium-mips.cc
@@ -1760,12 +1760,24 @@ LInstruction* LChunkBuilder::DoForceRepresentation(HForceRepresentation* bad) {
 LInstruction* LChunkBuilder::DoChange(HChange* instr) {
   Representation from = instr->from();
   Representation to = instr->to();
+  if (from.IsSmi()) {
+    if (to.IsTagged()) {
+      LOperand* value = UseRegister(instr->value());
+      return DefineSameAsFirst(new(zone()) LDummyUse(value));
+    }
+    from = Representation::Tagged();
+  }
   if (from.IsTagged()) {
     if (to.IsDouble()) {
       info()->MarkAsDeferredCalling();
       LOperand* value = UseRegister(instr->value());
       LNumberUntagD* res = new(zone()) LNumberUntagD(value);
       return AssignEnvironment(DefineAsRegister(res));
+    } else if (to.IsSmi()) {
+      HValue* val = instr->value();
+      LOperand* value = UseRegisterAtStart(val);
+      return AssignEnvironment(
+          DefineSameAsFirst(new(zone()) LCheckSmi(value)));
     } else {
       ASSERT(to.IsInteger32());
       LOperand* value = NULL;
@@ -1807,6 +1819,10 @@ LInstruction* LChunkBuilder::DoChange(HChange* instr) {
       LNumberTagD* result = new(zone()) LNumberTagD(value, temp1, temp2);
       Define(result, result_temp);
       return AssignPointerMap(result);
+    } else if (to.IsSmi()) {
+      LOperand* value = UseRegister(instr->value());
+      return AssignEnvironment(DefineAsRegister(new(zone()) LDoubleToSmi(value,
+          TempRegister(), TempRegister())));
     } else {
       ASSERT(to.IsInteger32());
       LOperand* value = UseRegister(instr->value());
@@ -1829,6 +1845,15 @@ LInstruction* LChunkBuilder::DoChange(HChange* instr) {
         LNumberTagI* result = new(zone()) LNumberTagI(value);
         return AssignEnvironment(AssignPointerMap(DefineAsRegister(result)));
       }
+    } else if (to.IsSmi()) {
+      HValue* val = instr->value();
+      LOperand* value = UseRegister(val);
+      LInstruction* result =
+          DefineSameAsFirst(new(zone()) LInteger32ToSmi(value));
+      if (val->HasRange() && val->range()->IsInSmiRange()) {
+        return result;
+      }
+      return AssignEnvironment(result);
     } else {
       ASSERT(to.IsDouble());
       if (instr->value()->CheckFlag(HInstruction::kUint32)) {
@@ -1923,7 +1948,7 @@ LInstruction* LChunkBuilder::DoConstant(HConstant* instr) {
     return DefineAsRegister(new(zone()) LConstantI);
   } else if (r.IsDouble()) {
     return DefineAsRegister(new(zone()) LConstantD);
-  } else if (r.IsTagged()) {
+  } else if (r.IsTagged() || r.IsSmi()) {
     return DefineAsRegister(new(zone()) LConstantT);
   } else {
     UNREACHABLE();