Rollback trunk to 3.21.15.

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index 6f4d3e309f49a43dc5b4ff789eec3ee3fd8a93e5..9dca6b3e20a4fccd4f006cf20c110784eb44d538 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -3520,7 +3520,7 @@ void LCodeGen::DoMathFloor(LMathFloor* instr) {
     __ bind(&negative_sign);
     // Truncate, then compare and compensate.
     __ cvttsd2si(output_reg, input_reg);
-    __ Cvtlsi2sd(xmm_scratch, output_reg);
+    __ cvtlsi2sd(xmm_scratch, output_reg);
     __ ucomisd(input_reg, xmm_scratch);
     __ j(equal, &done, Label::kNear);
     __ subl(output_reg, Immediate(1));
@@ -3569,7 +3569,7 @@ void LCodeGen::DoMathRound(LMathRound* instr) {
   __ RecordComment("D2I conversion overflow");
   DeoptimizeIf(equal, instr->environment());
 
-  __ Cvtlsi2sd(xmm_scratch, output_reg);
+  __ cvtlsi2sd(xmm_scratch, output_reg);
   __ ucomisd(input_reg, xmm_scratch);
   __ j(equal, &restore, Label::kNear);
   __ subl(output_reg, Immediate(1));
@@ -4449,9 +4449,9 @@ void LCodeGen::DoInteger32ToDouble(LInteger32ToDouble* instr) {
   LOperand* output = instr->result();
   ASSERT(output->IsDoubleRegister());
   if (input->IsRegister()) {
-    __ Cvtlsi2sd(ToDoubleRegister(output), ToRegister(input));
+    __ cvtlsi2sd(ToDoubleRegister(output), ToRegister(input));
   } else {
-    __ Cvtlsi2sd(ToDoubleRegister(output), ToOperand(input));
+    __ cvtlsi2sd(ToDoubleRegister(output), ToOperand(input));
   }
 }
 
@@ -4623,7 +4623,7 @@ void LCodeGen::EmitNumberUntagD(Register input_reg,
                                 bool deoptimize_on_minus_zero,
                                 LEnvironment* env,
                                 NumberUntagDMode mode) {
-  Label convert, load_smi, done;
+  Label load_smi, done;
 
   if (mode == NUMBER_CANDIDATE_IS_ANY_TAGGED) {
     // Smi check.
@@ -4632,17 +4632,25 @@ void LCodeGen::EmitNumberUntagD(Register input_reg,
     // Heap number map check.
     __ CompareRoot(FieldOperand(input_reg, HeapObject::kMapOffset),
                    Heap::kHeapNumberMapRootIndex);
-
-    // On x64 it is safe to load at heap number offset before evaluating the map
-    // check, since all heap objects are at least two words long.
-    __ movsd(result_reg, FieldOperand(input_reg, HeapNumber::kValueOffset));
-
-    if (can_convert_undefined_to_nan) {
-      __ j(not_equal, &convert);
+    if (!can_convert_undefined_to_nan) {
+      DeoptimizeIf(not_equal, env);
     } else {
+      Label heap_number, convert;
+      __ j(equal, &heap_number, Label::kNear);
+
+      // Convert undefined (and hole) to NaN. Compute NaN as 0/0.
+      __ CompareRoot(input_reg, Heap::kUndefinedValueRootIndex);
       DeoptimizeIf(not_equal, env);
-    }
 
+      __ bind(&convert);
+      __ xorps(result_reg, result_reg);
+      __ divsd(result_reg, result_reg);
+      __ jmp(&done, Label::kNear);
+
+      __ bind(&heap_number);
+    }
+    // Heap number to XMM conversion.
+    __ movsd(result_reg, FieldOperand(input_reg, HeapNumber::kValueOffset));
     if (deoptimize_on_minus_zero) {
       XMMRegister xmm_scratch = xmm0;
       __ xorps(xmm_scratch, xmm_scratch);
@@ -4653,18 +4661,6 @@ void LCodeGen::EmitNumberUntagD(Register input_reg,
       DeoptimizeIf(not_zero, env);
     }
     __ jmp(&done, Label::kNear);
-
-    if (can_convert_undefined_to_nan) {
-      __ bind(&convert);
-
-      // Convert undefined (and hole) to NaN. Compute NaN as 0/0.
-      __ CompareRoot(input_reg, Heap::kUndefinedValueRootIndex);
-      DeoptimizeIf(not_equal, env);
-
-      __ xorps(result_reg, result_reg);
-      __ divsd(result_reg, result_reg);
-      __ jmp(&done, Label::kNear);
-    }
   } else {
     ASSERT(mode == NUMBER_CANDIDATE_IS_SMI);
   }
@@ -4672,7 +4668,7 @@ void LCodeGen::EmitNumberUntagD(Register input_reg,
   // Smi to XMM conversion
   __ bind(&load_smi);
   __ SmiToInteger32(kScratchRegister, input_reg);
-  __ Cvtlsi2sd(result_reg, kScratchRegister);
+  __ cvtlsi2sd(result_reg, kScratchRegister);
   __ bind(&done);
 }