Implement optional turbofan UnalignedLoad and UnalignedStore operators

src/mips/constants-mips.h

 // Copyright 2012 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.
 
 #ifndef  V8_MIPS_CONSTANTS_H_
 #define  V8_MIPS_CONSTANTS_H_
 #include "src/globals.h"
 // UNIMPLEMENTED_ macro for MIPS.
 #ifdef DEBUG
 #define UNIMPLEMENTED_MIPS()                                                  \
@@ skipping 90 matching lines @@
 #define IsFpxxMode() (kFpuMode == kFPXX)
 
 #ifndef _MIPS_ARCH_MIPS32RX
 #define IsMipsArchVariant(check) \
   (kArchVariant == check)
 #else
 #define IsMipsArchVariant(check) \
   (CpuFeatures::IsSupported(static_cast<CpuFeature>(check)))
 #endif
 
+#if defined(V8_TARGET_LITTLE_ENDIAN)
+const uint32_t kMipsLwrOffset = 0;
+const uint32_t kMipsLwlOffset = 3;
+const uint32_t kMipsSwrOffset = 0;
+const uint32_t kMipsSwlOffset = 3;
+#elif defined(V8_TARGET_BIG_ENDIAN)
+const uint32_t kMipsLwrOffset = 3;
+const uint32_t kMipsLwlOffset = 0;
+const uint32_t kMipsSwrOffset = 3;
+const uint32_t kMipsSwlOffset = 0;
+#else
+#error Unknown endianness
+#endif
 
 #define __STDC_FORMAT_MACROS
 #include <inttypes.h>
 
 // Defines constants and accessor classes to assemble, disassemble and
 // simulate MIPS32 instructions.
 //
 // See: MIPS32 Architecture For Programmers
 //      Volume II: The MIPS32 Instruction Set
 // Try www.cs.cornell.edu/courses/cs3410/2008fa/MIPS_Vol2.pdf.
@@ skipping 1097 matching lines @@
       }
   }
 }
 
 #undef OpcodeToBitNumber
 #undef FunctionFieldToBitNumber
 }  // namespace internal
 }  // namespace v8
 
 #endif    // #ifndef V8_MIPS_CONSTANTS_H_