[x64] Load int32 constants with movl instead of movq to avoid sign extension.

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/1867293002

Cr-Commit-Position: refs/heads/master@{#35352}

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

@@ -2077,10 +2077,16 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
       Register dst = destination->IsRegister() ? g.ToRegister(destination)
                                                : kScratchRegister;
       switch (src.type()) {
-        case Constant::kInt32:
+        case Constant::kInt32: {
           // TODO(dcarney): don't need scratch in this case.
-          __ Set(dst, src.ToInt32());
+          int32_t value = src.ToInt32();
+          if (value == 0) {
+            __ xorl(dst, dst);
+          } else {
+            __ movl(dst, Immediate(value));
+          }
           break;
+        }
         case Constant::kInt64:
           __ Set(dst, src.ToInt64());
           break;

test/cctest/compiler/test-run-machops.cc

@@ -1774,7 +1774,6 @@ TEST(RunInt32SubP) {
   }
 }
 
-
 TEST(RunInt32SubImm) {
   {
     FOR_UINT32_INPUTS(i) {
@@ -1798,6 +1797,11 @@ TEST(RunInt32SubImm) {
   }
 }
 
+TEST(RunInt32SubImm2) {
+  BufferedRawMachineAssemblerTester<int32_t> r;
+  r.Return(r.Int32Sub(r.Int32Constant(-1), r.Int32Constant(0)));
+  CHECK_EQ(-1, r.Call());
+}
 
 TEST(RunInt32SubAndWord32SarP) {
   {