MIPS: Add big-endian support for MIPS.

src/mips/constants-mips.h

 // Copyright 2012 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 37 matching lines @@
 #ifdef _MIPS_ARCH_MIPS32R2
   static const ArchVariants kArchVariant = kMips32r2;
 #elif _MIPS_ARCH_LOONGSON
 // The loongson flag refers to the LOONGSON architectures based on MIPS-III,
 // which predates (and is a subset of) the mips32r2 and r1 architectures.
   static const ArchVariants kArchVariant = kLoongson;
 #else
   static const ArchVariants kArchVariant = kMips32r1;
 #endif
 
+enum Endianness {
+  kLittle,
+  kBig
+};
+
+#if defined(V8_TARGET_LITTLE_ENDIAN)
+  static const Endianness kArchEndian = kLittle;
+#elif defined(V8_TARGET_BIG_ENDIAN)
+  static const Endianness kArchEndian = kBig;
+#else
+#error Unknown endianness
+#endif
 
 #if(defined(__mips_hard_float) && __mips_hard_float != 0)
 // Use floating-point coprocessor instructions. This flag is raised when
 // -mhard-float is passed to the compiler.
 const bool IsMipsSoftFloatABI = false;
 #elif(defined(__mips_soft_float) && __mips_soft_float != 0)
 // This flag is raised when -msoft-float is passed to the compiler.
 // Although FPU is a base requirement for v8, soft-float ABI is used
 // on soft-float systems with FPU kernel emulation.
 const bool IsMipsSoftFloatABI = true;
 #else
 const bool IsMipsSoftFloatABI = true;
 #endif
 
+#if defined(V8_TARGET_LITTLE_ENDIAN)
+const uint32_t kHoleNanUpper32Offset = 4;
+const uint32_t kHoleNanLower32Offset = 0;
+#elif defined(V8_TARGET_BIG_ENDIAN)
+const uint32_t kHoleNanUpper32Offset = 0;
+const uint32_t kHoleNanLower32Offset = 4;
+#else
+#error Unknown endianness
+#endif
 
 // 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.
 
 namespace v8 {
 namespace internal {
@@ skipping 729 matching lines @@
 // JS argument slots size.
 const int kJSArgsSlotsSize = 0 * Instruction::kInstrSize;
 // Assembly builtins argument slots size.
 const int kBArgsSlotsSize = 0 * Instruction::kInstrSize;
 
 const int kBranchReturnOffset = 2 * Instruction::kInstrSize;
 
 } }   // namespace v8::internal
 
 #endif    // #ifndef V8_MIPS_CONSTANTS_H_