MIPS: crankshaft implementation

src/deoptimizer.h

 // Copyright 2011 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 351 matching lines @@
 
   JSFunction* GetFunction() const { return function_; }
 
   unsigned GetOffsetFromSlotIndex(Deoptimizer* deoptimizer, int slot_index);
 
   intptr_t GetFrameSlot(unsigned offset) {
     return *GetFrameSlotPointer(offset);
   }
 
   double GetDoubleFrameSlot(unsigned offset) {
-    return *reinterpret_cast<double*>(GetFrameSlotPointer(offset));
+    intptr_t* ptr = GetFrameSlotPointer(offset);
+#if V8_TARGET_ARCH_MIPS
+    // Prevent gcc from using load-double (mips ldc1) on (possibly)
+    // non-64-bit aligned double. Uses two lwc1 instructions.
+    union conversion {
+      double d;
+      uint32_t u[2];
+    } c;
+    c.u[0] = *reinterpret_cast<uint32_t*>(ptr);
+    c.u[1] = *(reinterpret_cast<uint32_t*>(ptr) + 1);
+    return c.d;
+#else
+    return *reinterpret_cast<double*>(ptr);
+#endif
   }
 
   void SetFrameSlot(unsigned offset, intptr_t value) {
     *GetFrameSlotPointer(offset) = value;
   }
 
   intptr_t GetRegister(unsigned n) const {
     ASSERT(n < ARRAY_SIZE(registers_));
     return registers_[n];
   }
@@ skipping 345 matching lines @@
   Object** parameters_;
   Object** expression_stack_;
 
   friend class Deoptimizer;
 };
 #endif
 
 } }  // namespace v8::internal
 
 #endif  // V8_DEOPTIMIZER_H_