MIPS: Remove soft-float support.

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 43 matching lines @@
 #else
   static const ArchVariants kArchVariant = kMips32r1;
 #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)
-// Not using floating-point coprocessor instructions. This flag is raised when
-// -msoft-float is passed to the compiler.
+// 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
 
 
 // Defines constants and accessor classes to assemble, disassemble and
 // simulate MIPS32 instructions.
 //
 // See: MIPS32 Architecture For Programmers
@@ skipping 722 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_