ARM: EmitNumberUntagD() Improvment

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index cf76a086720a7282487f2d59ddd09f6938c79759..e264cc7c4df768fe192beafe55f5882120d9eebf 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -4886,7 +4886,13 @@ void LCodeGen::EmitNumberUntagD(Register input_reg,
       DeoptimizeIf(ne, env);
     } else {
       Label heap_number, convert;
+      if (!deoptimize_on_minus_zero) {
+        __ vldr(result_reg, input_reg,
+                HeapNumber::kValueOffset - kHeapObjectTag, eq);
+        __ b(eq, &done);
+      } else {
       __ b(eq, &heap_number);

[Benedikt Meurer, 2013/09/12 07:23:41]

Nit: indentation.

+      }
 
       // Convert undefined (and hole) to NaN.
       __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
@@ -4900,8 +4906,11 @@ void LCodeGen::EmitNumberUntagD(Register input_reg,
 
       __ bind(&heap_number);
     }
+
     // Heap number to double register conversion.
-    __ vldr(result_reg, input_reg, HeapNumber::kValueOffset - kHeapObjectTag);
+    if (!can_convert_undefined_to_nan || deoptimize_on_minus_zero) {
+      __ vldr(result_reg, input_reg, HeapNumber::kValueOffset - kHeapObjectTag);
+    }
     if (deoptimize_on_minus_zero) {
       __ VmovLow(scratch, result_reg);
       __ cmp(scratch, Operand::Zero());
@@ -4925,6 +4934,7 @@ void LCodeGen::EmitNumberUntagD(Register input_reg,
 }
 
 
+

[Benedikt Meurer, 2013/09/12 07:23:41]

Nit: new line.

 void LCodeGen::DoDeferredTaggedToI(LTaggedToI* instr) {
   Register input_reg = ToRegister(instr->value());
   Register scratch1 = scratch0();