MIPS: Add big-endian support for MIPS.

src/mips/code-stubs-mips.cc

 // 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 541 matching lines @@
            (result2_.code() << 4) +
            (source_.code() << 8) +
            (zeros_.code() << 12);
   }
 
   void Generate(MacroAssembler* masm);
 };
 
 
 void ConvertToDoubleStub::Generate(MacroAssembler* masm) {
-#ifndef BIG_ENDIAN_FLOATING_POINT
-  Register exponent = result1_;
-  Register mantissa = result2_;
-#else
-  Register exponent = result2_;
-  Register mantissa = result1_;
-#endif
+  Register exponent, mantissa;
+  if (kArchEndian == kLittle) {
+    exponent = result1_;
+    mantissa = result2_;
+  } else {
+    exponent = result2_;
+    mantissa = result1_;
+  }
   Label not_special;
   // Convert from Smi to integer.
   __ sra(source_, source_, kSmiTagSize);
   // Move sign bit from source to destination.  This works because the sign bit
   // in the exponent word of the double has the same position and polarity as
   // the 2's complement sign bit in a Smi.
   STATIC_ASSERT(HeapNumber::kSignMask == 0x80000000u);
   __ And(exponent, source_, Operand(HeapNumber::kSignMask));
   // Subtract from 0 if source was negative.
   __ subu(at, zero_reg, source_);
@@ skipping 85 matching lines @@
     __ Branch(&error, ne, scratch, Operand(zero_reg));
     __ Move(result_reg, scratch3);
     __ Branch(&done);
     __ bind(&error);
   }
 
   // Load the double value and perform a manual truncation.
   Register input_high = scratch2;
   Register input_low = scratch3;
 
-  __ lw(input_low, MemOperand(input_reg, double_offset));
-  __ lw(input_high, MemOperand(input_reg, double_offset + kIntSize));
+  __ lw(input_low,
+      MemOperand(input_reg, double_offset + Register::kMantissaOffset));
+  __ lw(input_high,
+      MemOperand(input_reg, double_offset + Register::kExponentOffset));
 
   Label normal_exponent, restore_sign;
   // Extract the biased exponent in result.
   __ Ext(result_reg,
          input_high,
          HeapNumber::kExponentShift,
          HeapNumber::kExponentBits);
 
   // Check for Infinity and NaNs, which should return 0.
   __ Subu(scratch, result_reg, HeapNumber::kExponentMask);
@@ skipping 2839 matching lines @@
 
   __ And(scratch4, src, Operand(kReadAlignmentMask));
   __ Branch(&simple_loop, eq, scratch4, Operand(zero_reg));
 
   // Loop for src/dst that are not aligned the same way.
   // This loop uses lwl and lwr instructions. These instructions
   // depend on the endianness, and the implementation assumes little-endian.
   {
     Label loop;
     __ bind(&loop);
-    __ lwr(scratch1, MemOperand(src));
-    __ Addu(src, src, Operand(kReadAlignment));
-    __ lwl(scratch1, MemOperand(src, -1));
+    if (kArchEndian == kBig) {
+      __ lwl(scratch1, MemOperand(src));
+      __ Addu(src, src, Operand(kReadAlignment));
+      __ lwr(scratch1, MemOperand(src, -1));
+    } else {
+      __ lwr(scratch1, MemOperand(src));
+      __ Addu(src, src, Operand(kReadAlignment));
+      __ lwl(scratch1, MemOperand(src, -1));
+    }
     __ sw(scratch1, MemOperand(dest));
     __ Addu(dest, dest, Operand(kReadAlignment));
     __ Subu(scratch2, limit, dest);
     __ Branch(&loop, ge, scratch2, Operand(kReadAlignment));
   }
 
   __ Branch(&byte_loop);
 
   // Simple loop.
   // Copy words from src to dest, until less than four bytes left.
@@ skipping 2096 matching lines @@
                               MemOperand(fp, 6 * kPointerSize),
                               NULL);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS