MIPS: crankshaft implementation

src/deoptimizer.h

Index: src/deoptimizer.h
diff --git a/src/deoptimizer.h b/src/deoptimizer.h
index 33580a1b9cb58973e0e4552058f8aa05acdc9a40..284676c36eeef1152ef3731d716240b5058aeb25 100644
--- a/src/deoptimizer.h
+++ b/src/deoptimizer.h
@@ -369,7 +369,20 @@ class FrameDescription {
   }
 
   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) {