PPC: Work-around to preserve sNan bit

src/compiler/ppc/code-generator-ppc.cc

 // Copyright 2014 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/compiler/code-generator.h"
 
 #include "src/compilation-info.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
@@ skipping 2328 matching lines @@
           UNREACHABLE();  // TODO(dcarney): loading RPO constants on PPC.
           break;
       }
       if (destination->IsStackSlot()) {
         __ StoreP(dst, g.ToMemOperand(destination), r0);
       }
     } else {
       DoubleRegister dst = destination->IsFPRegister()
                                ? g.ToDoubleRegister(destination)
                                : kScratchDoubleReg;
-      double value = (src.type() == Constant::kFloat32) ? src.ToFloat32()
-                                                        : src.ToFloat64();
+      double value;
+// bit_cast of snan is converted to qnan on ia32/x64
+#if V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64
+      intptr_t valueInt = (src.type() == Constant::kFloat32)
+                              ? src.ToFloat32AsInt()
+                              : src.ToFloat64AsInt();
+      if (valueInt == ((src.type() == Constant::kFloat32)
+                           ? 0x7fa00000
+                           : 0x7fa0000000000000)) {
+        value = bit_cast<double, int64_t>(0x7ff4000000000000L);
+      } else {
+#endif
+        value = (src.type() == Constant::kFloat32) ? src.ToFloat32()
+                                                   : src.ToFloat64();
+#if V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64
+      }
+#endif
       __ LoadDoubleLiteral(dst, value, kScratchReg);
       if (destination->IsFPStackSlot()) {
         __ StoreDouble(dst, g.ToMemOperand(destination), r0);
       }
     }
   } else if (source->IsFPRegister()) {
     DoubleRegister src = g.ToDoubleRegister(source);
     if (destination->IsFPRegister()) {
       DoubleRegister dst = g.ToDoubleRegister(destination);
       __ Move(dst, src);
@@ skipping 129 matching lines @@
       padding_size -= v8::internal::Assembler::kInstrSize;
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8