[ia32/x64] Smaller instruction to check NaN

src/x64/lithium-codegen-x64.cc

 // Copyright 2013 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 2222 matching lines @@
     __ ucomisd(xmm_scratch, value);
     EmitFalseBranch(instr, not_equal);
     __ movmskpd(kScratchRegister, value);
     __ testl(kScratchRegister, Immediate(1));
     EmitBranch(instr, not_zero);
   } else {
     Register value = ToRegister(instr->value());
     Handle<Map> map = masm()->isolate()->factory()->heap_number_map();
     __ CheckMap(value, map, instr->FalseLabel(chunk()), DO_SMI_CHECK);
     __ cmpl(FieldOperand(value, HeapNumber::kExponentOffset),
-            Immediate(0x80000000));
-    EmitFalseBranch(instr, not_equal);
+            Immediate(0x1));
+    EmitFalseBranch(instr, no_overflow);
     __ cmpl(FieldOperand(value, HeapNumber::kMantissaOffset),
             Immediate(0x00000000));
     EmitBranch(instr, equal);
   }
 }
 
 
 Condition LCodeGen::EmitIsObject(Register input,
                                  Label* is_not_object,
                                  Label* is_object) {
@@ skipping 1294 matching lines @@
   if (CpuFeatures::IsSupported(SSE4_1)) {
     CpuFeatureScope scope(masm(), SSE4_1);
     if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
       // Deoptimize if minus zero.
       __ movq(output_reg, input_reg);
       __ subq(output_reg, Immediate(1));
       DeoptimizeIf(overflow, instr->environment());
     }
     __ roundsd(xmm_scratch, input_reg, Assembler::kRoundDown);
     __ cvttsd2si(output_reg, xmm_scratch);
-    __ cmpl(output_reg, Immediate(0x80000000));
-    DeoptimizeIf(equal, instr->environment());
+    __ cmpl(output_reg, Immediate(0x1));
+    DeoptimizeIf(overflow, instr->environment());
   } else {
     Label negative_sign, done;
     // Deoptimize on unordered.
     __ xorps(xmm_scratch, xmm_scratch);  // Zero the register.
     __ ucomisd(input_reg, xmm_scratch);
     DeoptimizeIf(parity_even, instr->environment());
     __ j(below, &negative_sign, Label::kNear);
 
     if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
       // Check for negative zero.
       Label positive_sign;
       __ j(above, &positive_sign, Label::kNear);
       __ movmskpd(output_reg, input_reg);
       __ testq(output_reg, Immediate(1));
       DeoptimizeIf(not_zero, instr->environment());
       __ Set(output_reg, 0);
       __ jmp(&done, Label::kNear);
       __ bind(&positive_sign);
     }
 
     // Use truncating instruction (OK because input is positive).
     __ cvttsd2si(output_reg, input_reg);
     // Overflow is signalled with minint.
-    __ cmpl(output_reg, Immediate(0x80000000));
-    DeoptimizeIf(equal, instr->environment());
+    __ cmpl(output_reg, Immediate(0x1));
+    DeoptimizeIf(overflow, instr->environment());
     __ jmp(&done, Label::kNear);
 
     // Non-zero negative reaches here.
     __ bind(&negative_sign);
     // Truncate, then compare and compensate.
     __ cvttsd2si(output_reg, input_reg);
     __ Cvtlsi2sd(xmm_scratch, output_reg);
     __ ucomisd(input_reg, xmm_scratch);
     __ j(equal, &done, Label::kNear);
     __ subl(output_reg, Immediate(1));
@@ skipping 16 matching lines @@
   Label::Distance dist = DeoptEveryNTimes() ? Label::kFar : Label::kNear;
   __ movq(kScratchRegister, one_half);
   __ movq(xmm_scratch, kScratchRegister);
   __ ucomisd(xmm_scratch, input_reg);
   __ j(above, &below_one_half, Label::kNear);
 
   // CVTTSD2SI rounds towards zero, since 0.5 <= x, we use floor(0.5 + x).
   __ addsd(xmm_scratch, input_reg);
   __ cvttsd2si(output_reg, xmm_scratch);
   // Overflow is signalled with minint.
-  __ cmpl(output_reg, Immediate(0x80000000));
+  __ cmpl(output_reg, Immediate(0x1));
   __ RecordComment("D2I conversion overflow");
-  DeoptimizeIf(equal, instr->environment());
+  DeoptimizeIf(overflow, instr->environment());
   __ jmp(&done, dist);
 
   __ bind(&below_one_half);
   __ movq(kScratchRegister, minus_one_half);
   __ movq(xmm_scratch, kScratchRegister);
   __ ucomisd(xmm_scratch, input_reg);
   __ j(below_equal, &round_to_zero, Label::kNear);
 
   // CVTTSD2SI rounds towards zero, we use ceil(x - (-0.5)) and then
   // compare and compensate.
   __ movq(input_temp, input_reg);  // Do not alter input_reg.
   __ subsd(input_temp, xmm_scratch);
   __ cvttsd2si(output_reg, input_temp);
   // Catch minint due to overflow, and to prevent overflow when compensating.
-  __ cmpl(output_reg, Immediate(0x80000000));
+  __ cmpl(output_reg, Immediate(0x1));
   __ RecordComment("D2I conversion overflow");
-  DeoptimizeIf(equal, instr->environment());
+  DeoptimizeIf(overflow, instr->environment());
 
   __ Cvtlsi2sd(xmm_scratch, output_reg);
   __ ucomisd(xmm_scratch, input_temp);
   __ j(equal, &done, dist);
   __ subl(output_reg, Immediate(1));
   // No overflow because we already ruled out minint.
   __ jmp(&done, dist);
 
   __ bind(&round_to_zero);
   // We return 0 for the input range [+0, 0.5[, or [-0.5, 0.5[ if
@@ skipping 1012 matching lines @@
   __ movp(reg, kScratchRegister);
 }
 
 
 void LCodeGen::DoSmiTag(LSmiTag* instr) {
   HChange* hchange = instr->hydrogen();
   Register input = ToRegister(instr->value());
   Register output = ToRegister(instr->result());
   if (hchange->CheckFlag(HValue::kCanOverflow) &&
       hchange->value()->CheckFlag(HValue::kUint32)) {
-    __ testl(input, Immediate(0x80000000));
-    DeoptimizeIf(not_zero, instr->environment());
+    __ testl(input, input);
+    DeoptimizeIf(sign, instr->environment());
   }
   __ Integer32ToSmi(output, input);
   if (hchange->CheckFlag(HValue::kCanOverflow) &&
       !hchange->value()->CheckFlag(HValue::kUint32)) {
     DeoptimizeIf(overflow, instr->environment());
   }
 }
 
 
 void LCodeGen::DoSmiUntag(LSmiUntag* instr) {
@@ skipping 374 matching lines @@
 
   // Check for heap number
   __ Cmp(FieldOperand(input_reg, HeapObject::kMapOffset),
          factory()->heap_number_map());
   __ j(equal, &heap_number, Label::kNear);
 
   // Check for undefined. Undefined is converted to zero for clamping
   // conversions.
   __ Cmp(input_reg, factory()->undefined_value());
   DeoptimizeIf(not_equal, instr->environment());
-  __ movp(input_reg, Immediate(0));
+  __ xorl(input_reg, input_reg);
   __ jmp(&done, Label::kNear);
 
   // Heap number
   __ bind(&heap_number);
   __ movsd(xmm_scratch, FieldOperand(input_reg, HeapNumber::kValueOffset));
   __ ClampDoubleToUint8(xmm_scratch, temp_xmm_reg, input_reg);
   __ jmp(&done, Label::kNear);
 
   // smi
   __ bind(&is_smi);
@@ skipping 561 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64