MIPS: Use signaling NaN for holes in fixed double arrays.

src/mips/lithium-codegen-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.7
 // 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 1726 matching lines @@
 
 
 void LCodeGen::DoConstantS(LConstantS* instr) {
   __ li(ToRegister(instr->result()), Operand(instr->value()));
 }
 
 
 void LCodeGen::DoConstantD(LConstantD* instr) {
   DCHECK(instr->result()->IsDoubleRegister());
   DoubleRegister result = ToDoubleRegister(instr->result());
+#if V8_HOST_ARCH_IA32
+  // Need some crappy work-around for x87 sNaN -> qNaN breakage in simulator
+  // builds.
+  uint64_t bits = instr->bits();
+  if ((bits & V8_UINT64_C(0x7FF8000000000000)) ==
+      V8_UINT64_C(0x7FF0000000000000)) {
+    uint32_t lo = static_cast<uint32_t>(bits);
+    uint32_t hi = static_cast<uint32_t>(bits >> 32);
+    __ li(at, Operand(lo));
+    __ li(scratch0(), Operand(hi));
+    __ Move(result, at, scratch0());
+    return;
+  }
+#endif
   double v = instr->value();
   __ Move(result, v);
 }
 
 
 void LCodeGen::DoConstantE(LConstantE* instr) {
   __ li(ToRegister(instr->result()), Operand(instr->value()));
 }
 
 
@@ skipping 4197 matching lines @@
   __ li(at, scope_info);
   __ Push(at, ToRegister(instr->function()));
   CallRuntime(Runtime::kPushBlockContext, 2, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal