Support conversion of clamped double values for pixel arrays in Crankshaft.

src/ia32/lithium-ia32.cc

Index: src/ia32/lithium-ia32.cc
diff --git a/src/ia32/lithium-ia32.cc b/src/ia32/lithium-ia32.cc
index 4acbf7201799b93f429461a3d712fa89c3011671..ee4f5c66826a5a8ebe1ba50630e6ec58c17d7ac5 100644
--- a/src/ia32/lithium-ia32.cc
+++ b/src/ia32/lithium-ia32.cc
@@ -1778,6 +1778,27 @@ LInstruction* LChunkBuilder::DoCheckMap(HCheckMap* instr) {
 }
 
 
+LInstruction* LChunkBuilder::DoClampToUint8(HClampToUint8* instr) {
+  HValue* value = instr->value();
+  Representation input_rep = value->representation();
+  if (input_rep.IsDouble()) {
+    LOperand* reg = UseRegister(value);
+    return DefineAsRegister(new LClampDoubleToUint8(reg));
+  } else if (input_rep.IsInteger32()) {
+    LOperand* reg = UseFixed(value, eax);
+    return DefineFixed(new LClampIToUint8(reg), eax);
+  } else {
+    ASSERT(input_rep.IsTagged());
+    LOperand* reg = UseFixed(value, eax);
+    // Register allocator doesn't (yet) support allocation of double
+    // temps. Reserve xmm1 explicitly.
+    LOperand* temp = FixedTemp(xmm1);
+    LClampTaggedToUint8* result = new LClampTaggedToUint8(reg, temp);
+    return AssignEnvironment(DefineFixed(result, eax));
+  }
+}
+
+
 LInstruction* LChunkBuilder::DoReturn(HReturn* instr) {
   return new LReturn(UseFixed(instr->value(), eax));
 }
@@ -1988,14 +2009,6 @@ LInstruction* LChunkBuilder::DoStoreKeyedSpecializedArrayElement(
   LOperand* external_pointer = UseRegister(instr->external_pointer());
   LOperand* key = UseRegisterOrConstant(instr->key());
   LOperand* temp = NULL;
-
-  if (array_type == kExternalPixelArray) {
-    // The generated code for pixel array stores requires that the clamped value
-    // is in a byte register. eax is an arbitrary choice to satisfy this
-    // requirement.
-    temp = FixedTemp(eax);
-  }
-
   LOperand* val = NULL;
   if (array_type == kExternalByteArray ||
       array_type == kExternalUnsignedByteArray) {