[x64] Recognize MOVSXWL.

src/compiler/x64/code-generator-x64.cc

Index: src/compiler/x64/code-generator-x64.cc
diff --git a/src/compiler/x64/code-generator-x64.cc b/src/compiler/x64/code-generator-x64.cc
index a867f4a72c880e0211859ec7e8ac2996d64dc8d0..8a61d371bffed90e013b224aa674927407e9b63a 100644
--- a/src/compiler/x64/code-generator-x64.cc
+++ b/src/compiler/x64/code-generator-x64.cc
@@ -484,6 +484,7 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       break;
     case kX64Movsxbl:
       __ movsxbl(i.OutputRegister(), i.MemoryOperand());
+      __ AssertZeroExtended(i.OutputRegister());
       break;
     case kX64Movzxbl:
       __ movzxbl(i.OutputRegister(), i.MemoryOperand());
@@ -499,10 +500,18 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       break;
     }
     case kX64Movsxwl:
-      __ movsxwl(i.OutputRegister(), i.MemoryOperand());
+      if (instr->addressing_mode() != kMode_None) {
+        __ movsxwl(i.OutputRegister(), i.MemoryOperand());
+      } else if (instr->InputAt(0)->IsRegister()) {
+        __ movsxwl(i.OutputRegister(), i.InputRegister(0));
+      } else {
+        __ movsxwl(i.OutputRegister(), i.InputOperand(0));
+      }
+      __ AssertZeroExtended(i.OutputRegister());
       break;
     case kX64Movzxwl:
       __ movzxwl(i.OutputRegister(), i.MemoryOperand());
+      __ AssertZeroExtended(i.OutputRegister());
       break;
     case kX64Movw: {
       int index = 0;
@@ -525,6 +534,7 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
         } else {
           __ movl(i.OutputRegister(), i.MemoryOperand());
         }
+        __ AssertZeroExtended(i.OutputRegister());
       } else {
         int index = 0;
         Operand operand = i.MemoryOperand(&index);
@@ -576,6 +586,7 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       break;
     case kX64Lea32:
       __ leal(i.OutputRegister(), i.MemoryOperand());
+      __ AssertZeroExtended(i.OutputRegister());
       break;
     case kX64Lea:
       __ leaq(i.OutputRegister(), i.MemoryOperand());