Synchronizing Comparison codegen between X64 and ia32.

src/x64/codegen-x64.cc

Index: src/x64/codegen-x64.cc
diff --git a/src/x64/codegen-x64.cc b/src/x64/codegen-x64.cc
index 473fead53d7dc146c40b887f07dc1295f947e28b..b25d74afc46249c8581b804449a5394579410a27 100644
--- a/src/x64/codegen-x64.cc
+++ b/src/x64/codegen-x64.cc
@@ -5739,48 +5739,55 @@ void CodeGenerator::Comparison(AstNode* node,
       // by reconstituting them on the non-fall-through path.
       JumpTarget is_smi;
 
-      Condition left_is_smi = masm_->CheckSmi(left_side.reg());
-      is_smi.Branch(left_is_smi);
-
-      bool is_loop_condition = (node->AsExpression() != NULL) &&
-          node->AsExpression()->is_loop_condition();
-      if (!is_loop_condition && right_val->IsSmi()) {
-        // Right side is a constant smi and left side has been checked
-        // not to be a smi.
-        JumpTarget not_number;
-        __ Cmp(FieldOperand(left_reg, HeapObject::kMapOffset),
-               Factory::heap_number_map());
-        not_number.Branch(not_equal, &left_side);
-        __ movsd(xmm1,
-                 FieldOperand(left_reg, HeapNumber::kValueOffset));
-        int value = Smi::cast(*right_val)->value();
-        if (value == 0) {
-          __ xorpd(xmm0, xmm0);
-        } else {
-          Result temp = allocator()->Allocate();
-          __ movl(temp.reg(), Immediate(value));
-          __ cvtlsi2sd(xmm0, temp.reg());
-          temp.Unuse();
+      if (left_side.is_smi()) {
+        if (FLAG_debug_code) {
+          __ AbortIfNotSmi(left_side.reg(), "Non-smi value inferred as smi.");
+        }
+      } else {
+        Condition left_is_smi = masm_->CheckSmi(left_side.reg());
+        is_smi.Branch(left_is_smi);
+
+        bool is_loop_condition = (node->AsExpression() != NULL) &&
+            node->AsExpression()->is_loop_condition();
+        if (!is_loop_condition && right_val->IsSmi()) {
+          // Right side is a constant smi and left side has been checked
+          // not to be a smi.
+          JumpTarget not_number;
+          __ Cmp(FieldOperand(left_reg, HeapObject::kMapOffset),
+                 Factory::heap_number_map());
+          not_number.Branch(not_equal, &left_side);
+          __ movsd(xmm1,
+              FieldOperand(left_reg, HeapNumber::kValueOffset));
+          int value = Smi::cast(*right_val)->value();
+          if (value == 0) {
+            __ xorpd(xmm0, xmm0);
+          } else {
+            Result temp = allocator()->Allocate();
+            __ movl(temp.reg(), Immediate(value));
+            __ cvtlsi2sd(xmm0, temp.reg());
+            temp.Unuse();
+          }
+          __ ucomisd(xmm1, xmm0);
+          // Jump to builtin for NaN.
+          not_number.Branch(parity_even, &left_side);
+          left_side.Unuse();
+          dest->true_target()->Branch(DoubleCondition(cc));
+          dest->false_target()->Jump();
+          not_number.Bind(&left_side);
         }
-        __ ucomisd(xmm1, xmm0);
-        // Jump to builtin for NaN.
-        not_number.Branch(parity_even, &left_side);
-        left_side.Unuse();
-        dest->true_target()->Branch(DoubleCondition(cc));
+
+        // Setup and call the compare stub.
+        CompareStub stub(cc, strict, kCantBothBeNaN);
+        Result result = frame_->CallStub(&stub, &left_side, &right_side);
+        result.ToRegister();
+        __ testq(result.reg(), result.reg());
+        result.Unuse();
+        dest->true_target()->Branch(cc);
         dest->false_target()->Jump();
-        not_number.Bind(&left_side);
-      }
 
-      // Setup and call the compare stub.
-      CompareStub stub(cc, strict, kCantBothBeNaN);
-      Result result = frame_->CallStub(&stub, &left_side, &right_side);
-      result.ToRegister();
-      __ testq(result.reg(), result.reg());
-      result.Unuse();
-      dest->true_target()->Branch(cc);
-      dest->false_target()->Jump();
+        is_smi.Bind();
+      }
 
-      is_smi.Bind();
       left_side = Result(left_reg);
       right_side = Result(right_val);
       // Test smi equality and comparison by signed int comparison.
@@ -5952,7 +5959,7 @@ void CodeGenerator::Comparison(AstNode* node,
         // If the first character is the same then the long string sorts after
         // the short one.
         __ SmiCompare(FieldOperand(left_side.reg(), String::kLengthOffset),
-               Smi::FromInt(1));
+                      Smi::FromInt(1));
         __ bind(&characters_were_different);
       }
       temp2.Unuse();