Use VLDR instead of VMOVs from GPR when a 64-bit double can't be encoded as a VMOV immediate.

src/assembler.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 192 matching lines @@
     EXTERNAL_REFERENCE,  // The address of an external C++ function.
     INTERNAL_REFERENCE,  // An address inside the same function.
 
     // Marks a constant pool. Only used on ARM.
     // It uses a custom noncompact encoding.
     CONST_POOL,
 
     // add more as needed
     // Pseudo-types
     NUMBER_OF_MODES,  // There are at most 15 modes with noncompact encoding.
-    NONE,  // never recorded
+    NONE,  // never recorded 32-bit value
+    NONE64,  // never recorded 64-bit value
     LAST_CODE_ENUM = DEBUG_BREAK,
     LAST_GCED_ENUM = GLOBAL_PROPERTY_CELL,
     // Modes <= LAST_COMPACT_ENUM are guaranteed to have compact encoding.
     LAST_COMPACT_ENUM = CODE_TARGET_WITH_ID,
     LAST_STANDARD_NONCOMPACT_ENUM = INTERNAL_REFERENCE
   };
 
 
   RelocInfo() {}
 
-  RelocInfo(byte* pc, Mode rmode, intptr_t data, Code* host)
+  explicit RelocInfo(byte* pc, Mode rmode, intptr_t data, Code* host)

[ulan, 2012/10/22 09:18:25]

No need for explicit here and below since the number of arguments != 1

       : pc_(pc), rmode_(rmode), data_(data), host_(host) {
   }
+  explicit RelocInfo(byte* pc, double data64)
+      : pc_(pc), rmode_(NONE64), data64_(data64), host_(NULL) {
+  }
 
   static inline bool IsConstructCall(Mode mode) {
     return mode == CONSTRUCT_CALL;
   }
   static inline bool IsCodeTarget(Mode mode) {
     return mode <= LAST_CODE_ENUM;
   }
   static inline bool IsEmbeddedObject(Mode mode) {
     return mode == EMBEDDED_OBJECT;
   }
@@ skipping 18 matching lines @@
   }
   static inline bool IsExternalReference(Mode mode) {
     return mode == EXTERNAL_REFERENCE;
   }
   static inline bool IsInternalReference(Mode mode) {
     return mode == INTERNAL_REFERENCE;
   }
   static inline bool IsDebugBreakSlot(Mode mode) {
     return mode == DEBUG_BREAK_SLOT;
   }
+  static inline bool IsNone(Mode mode) {
+    return mode == NONE || mode == NONE64;
+  }
   static inline int ModeMask(Mode mode) { return 1 << mode; }
 
   // Accessors
   byte* pc() const { return pc_; }
   void set_pc(byte* pc) { pc_ = pc; }
   Mode rmode() const {  return rmode_; }
   intptr_t data() const { return data_; }
+  double data64() const { return data64_; }
   Code* host() const { return host_; }
 
   // Apply a relocation by delta bytes
   INLINE(void apply(intptr_t delta));
 
   // Is the pointer this relocation info refers to coded like a plain pointer
   // or is it strange in some way (e.g. relative or patched into a series of
   // instructions).
   bool IsCodedSpecially();
 
@@ skipping 77 matching lines @@
       (1 << CODE_TARGET_WITH_ID) | kPositionMask | (1 << COMMENT);
   static const int kApplyMask;  // Modes affected by apply. Depends on arch.
 
  private:
   // On ARM, note that pc_ is the address of the constant pool entry
   // to be relocated and not the address of the instruction
   // referencing the constant pool entry (except when rmode_ ==
   // comment).
   byte* pc_;
   Mode rmode_;
-  intptr_t data_;
+  union {
+    intptr_t data_;
+    double data64_;
+  };
   Code* host_;
 #ifdef V8_TARGET_ARCH_MIPS
   // Code and Embedded Object pointers in mips are stored split
   // across two consecutive 32-bit instructions. Heap management
   // routines expect to access these pointers indirectly. The following
   // location provides a place for these pointers to exist natually
   // when accessed via the Iterator.
   Object* reconstructed_obj_ptr_;
   // External-reference pointers are also split across instruction-pairs
   // in mips, but are accessed via indirect pointers. This location
@@ skipping 509 matching lines @@
  public:
   NullCallWrapper() { }
   virtual ~NullCallWrapper() { }
   virtual void BeforeCall(int call_size) const { }
   virtual void AfterCall() const { }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ASSEMBLER_H_