Use signaling NaN for holes in fixed double arrays.

src/ia32/lithium-codegen-ia32.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_IA32
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 1691 matching lines @@
   __ Move(ToRegister(instr->result()), Immediate(instr->value()));
 }
 
 
 void LCodeGen::DoConstantS(LConstantS* instr) {
   __ Move(ToRegister(instr->result()), Immediate(instr->value()));
 }
 
 
 void LCodeGen::DoConstantD(LConstantD* instr) {
-  double v = instr->value();
-  uint64_t int_val = bit_cast<uint64_t, double>(v);
-  int32_t lower = static_cast<int32_t>(int_val);
-  int32_t upper = static_cast<int32_t>(int_val >> (kBitsPerInt));
+  uint64_t const bits = instr->bits();
+  uint32_t const lower = static_cast<uint32_t>(bits);
+  uint32_t const upper = static_cast<uint32_t>(bits >> 32);
   DCHECK(instr->result()->IsDoubleRegister());
 
-  XMMRegister res = ToDoubleRegister(instr->result());
-  if (int_val == 0) {
-    __ xorps(res, res);
+  XMMRegister result = ToDoubleRegister(instr->result());
+  if (bits == 0u) {
+    __ xorps(result, result);
   } else {
     Register temp = ToRegister(instr->temp());
     if (CpuFeatures::IsSupported(SSE4_1)) {
       CpuFeatureScope scope2(masm(), SSE4_1);
       if (lower != 0) {
         __ Move(temp, Immediate(lower));
-        __ movd(res, Operand(temp));
+        __ movd(result, Operand(temp));
         __ Move(temp, Immediate(upper));
-        __ pinsrd(res, Operand(temp), 1);
+        __ pinsrd(result, Operand(temp), 1);
       } else {
-        __ xorps(res, res);
+        __ xorps(result, result);
         __ Move(temp, Immediate(upper));
-        __ pinsrd(res, Operand(temp), 1);
+        __ pinsrd(result, Operand(temp), 1);
       }
     } else {
       __ Move(temp, Immediate(upper));
-      __ movd(res, Operand(temp));
-      __ psllq(res, 32);
-      if (lower != 0) {
+      __ movd(result, Operand(temp));
+      __ psllq(result, 32);
+      if (lower != 0u) {
         XMMRegister xmm_scratch = double_scratch0();
         __ Move(temp, Immediate(lower));
         __ movd(xmm_scratch, Operand(temp));
-        __ orps(res, xmm_scratch);
+        __ orps(result, xmm_scratch);
       }
     }
   }
 }
 
 
 void LCodeGen::DoConstantE(LConstantE* instr) {
   __ lea(ToRegister(instr->result()), Operand::StaticVariable(instr->value()));
 }
 
@@ skipping 2133 matching lines @@
 
 void LCodeGen::DoMathLog(LMathLog* instr) {
   DCHECK(instr->value()->Equals(instr->result()));
   XMMRegister input_reg = ToDoubleRegister(instr->value());
   XMMRegister xmm_scratch = double_scratch0();
   Label positive, done, zero;
   __ xorps(xmm_scratch, xmm_scratch);
   __ ucomisd(input_reg, xmm_scratch);
   __ j(above, &positive, Label::kNear);
   __ j(not_carry, &zero, Label::kNear);
-  ExternalReference nan =
-      ExternalReference::address_of_canonical_non_hole_nan();
-  __ movsd(input_reg, Operand::StaticVariable(nan));
+  __ pcmpeqd(input_reg, input_reg);
   __ jmp(&done, Label::kNear);
   __ bind(&zero);
   ExternalReference ninf =
       ExternalReference::address_of_negative_infinity();
   __ movsd(input_reg, Operand::StaticVariable(ninf));
   __ jmp(&done, Label::kNear);
   __ bind(&positive);
   __ fldln2();
   __ sub(Operand(esp), Immediate(kDoubleSize));
   __ movsd(Operand(esp, 0), input_reg);
@@ skipping 333 matching lines @@
       case DICTIONARY_ELEMENTS:
       case SLOPPY_ARGUMENTS_ELEMENTS:
         UNREACHABLE();
         break;
     }
   }
 }
 
 
 void LCodeGen::DoStoreKeyedFixedDoubleArray(LStoreKeyed* instr) {
-  ExternalReference canonical_nan_reference =
-      ExternalReference::address_of_canonical_non_hole_nan();
   Operand double_store_operand = BuildFastArrayOperand(
       instr->elements(),
       instr->key(),
       instr->hydrogen()->key()->representation(),
       FAST_DOUBLE_ELEMENTS,
       instr->base_offset());
 
   XMMRegister value = ToDoubleRegister(instr->value());
 
   if (instr->NeedsCanonicalization()) {
-    Label have_value;
-
-    __ ucomisd(value, value);
-    __ j(parity_odd, &have_value, Label::kNear);  // NaN.
-
-    __ movsd(value, Operand::StaticVariable(canonical_nan_reference));
-    __ bind(&have_value);
+    XMMRegister xmm_scratch = double_scratch0();
+    // Turn potential sNaN value into qNaN.
+    __ xorps(xmm_scratch, xmm_scratch);
+    __ subsd(value, xmm_scratch);
   }
 
   __ movsd(double_store_operand, value);
 }
 
 
 void LCodeGen::DoStoreKeyedFixedArray(LStoreKeyed* instr) {
   Register elements = ToRegister(instr->elements());
   Register key = instr->key()->IsRegister() ? ToRegister(instr->key()) : no_reg;
 
@@ skipping 468 matching lines @@
       __ j(not_zero, &done, Label::kNear);
       __ movmskpd(temp_reg, result_reg);
       __ test_b(temp_reg, 1);
       DeoptimizeIf(not_zero, instr, "minus zero");
     }
     __ jmp(&done, Label::kNear);
 
     if (can_convert_undefined_to_nan) {
       __ bind(&convert);
 
-      // Convert undefined (and hole) to NaN.
+      // Convert undefined to NaN.
       __ cmp(input_reg, factory()->undefined_value());
       DeoptimizeIf(not_equal, instr, "not a heap number/undefined");
 
-      ExternalReference nan =
-          ExternalReference::address_of_canonical_non_hole_nan();
-      __ movsd(result_reg, Operand::StaticVariable(nan));
+      __ pcmpeqd(result_reg, result_reg);
       __ jmp(&done, Label::kNear);
     }
   } else {
     DCHECK(mode == NUMBER_CANDIDATE_IS_SMI);
   }
 
   __ bind(&load_smi);
   // Smi to XMM conversion. Clobbering a temp is faster than re-tagging the
   // input register since we avoid dependencies.
   __ mov(temp_reg, input_reg);
@@ skipping 983 matching lines @@
   CallRuntime(Runtime::kPushBlockContext, 2, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32