ARM: EmitNumberUntagD() Improvment

src/arm/lithium-codegen-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4868 matching lines @@
     __ UntagAndJumpIfSmi(scratch, input_reg, &load_smi);
 
     // Heap number map check.
     __ ldr(scratch, FieldMemOperand(input_reg, HeapObject::kMapOffset));
     __ LoadRoot(ip, Heap::kHeapNumberMapRootIndex);
     __ cmp(scratch, Operand(ip));
     if (!can_convert_undefined_to_nan) {
       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);
       __ cmp(input_reg, Operand(ip));
       DeoptimizeIf(ne, env);
 
       __ bind(&convert);
       __ LoadRoot(scratch, Heap::kNanValueRootIndex);
       __ vldr(result_reg, scratch, HeapNumber::kValueOffset - kHeapObjectTag);
       __ jmp(&done);
 
       __ 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());
       __ b(ne, &done);
       __ VmovHigh(scratch, result_reg);
       __ cmp(scratch, Operand(HeapNumber::kSignMask));
       DeoptimizeIf(eq, env);
     }
     __ jmp(&done);
   } else {
     __ SmiUntag(scratch, input_reg);
     ASSERT(mode == NUMBER_CANDIDATE_IS_SMI);
   }
 
   // Smi to double register conversion
   __ bind(&load_smi);
   // scratch: untagged value of input_reg
   __ vmov(flt_scratch, scratch);
   __ vcvt_f64_s32(result_reg, flt_scratch);
   __ bind(&done);
 }
 
 
+

[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();
   Register scratch2 = ToRegister(instr->temp());
   LowDwVfpRegister double_scratch = double_scratch0();
   DwVfpRegister double_scratch2 = ToDoubleRegister(instr->temp2());
 
   ASSERT(!scratch1.is(input_reg) && !scratch1.is(scratch2));
   ASSERT(!scratch2.is(input_reg) && !scratch2.is(scratch1));
 
@@ skipping 855 matching lines @@
   __ sub(scratch, result, Operand::PointerOffsetFromSmiKey(index));
   __ ldr(result, FieldMemOperand(scratch,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal