LoadUint32() doesn't need a scratch register.

src/ia32/lithium-ia32.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_IA32_LITHIUM_IA32_H_
 #define V8_IA32_LITHIUM_IA32_H_
 
 #include "hydrogen.h"
 #include "lithium-allocator.h"
 #include "lithium.h"
@@ skipping 1979 matching lines @@
   explicit LInteger32ToDouble(LOperand* value) {
     inputs_[0] = value;
   }
 
   LOperand* value() { return inputs_[0]; }
 
   DECLARE_CONCRETE_INSTRUCTION(Integer32ToDouble, "int32-to-double")
 };
 
 
-class LUint32ToDouble V8_FINAL : public LTemplateInstruction<1, 1, 1> {
+class LUint32ToDouble V8_FINAL : public LTemplateInstruction<1, 1, 0> {
  public:
-  explicit LUint32ToDouble(LOperand* value, LOperand* temp) {
+  explicit LUint32ToDouble(LOperand* value) {
     inputs_[0] = value;
-    temps_[0] = temp;
   }
 
   LOperand* value() { return inputs_[0]; }
-  LOperand* temp() { return temps_[0]; }
 
   DECLARE_CONCRETE_INSTRUCTION(Uint32ToDouble, "uint32-to-double")
 };
 
 
 class LNumberTagI V8_FINAL : public LTemplateInstruction<1, 1, 1> {
  public:
   LNumberTagI(LOperand* value, LOperand* temp) {
     inputs_[0] = value;
     temps_[0] = temp;
   }
 
   LOperand* value() { return inputs_[0]; }
   LOperand* temp() { return temps_[0]; }
 
   DECLARE_CONCRETE_INSTRUCTION(NumberTagI, "number-tag-i")
 };
 
 
-class LNumberTagU V8_FINAL : public LTemplateInstruction<1, 1, 2> {
+class LNumberTagU V8_FINAL : public LTemplateInstruction<1, 1, 1> {
  public:
-  LNumberTagU(LOperand* value, LOperand* temp1, LOperand* temp2) {
+  LNumberTagU(LOperand* value, LOperand* temp) {
     inputs_[0] = value;
-    temps_[0] = temp1;
-    temps_[1] = temp2;
+    temps_[0] = temp;
   }
 
   LOperand* value() { return inputs_[0]; }
-  LOperand* temp1() { return temps_[0]; }
-  LOperand* temp2() { return temps_[1]; }
+  LOperand* temp() { return temps_[0]; }
 
   DECLARE_CONCRETE_INSTRUCTION(NumberTagU, "number-tag-u")
 };
 
 
 class LNumberTagD V8_FINAL : public LTemplateInstruction<1, 1, 1> {
  public:
   LNumberTagD(LOperand* value, LOperand* temp) {
     inputs_[0] = value;
     temps_[0] = temp;
@@ skipping 804 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);
 };
 
 #undef DECLARE_HYDROGEN_ACCESSOR
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_IA32_LITHIUM_IA32_H_