MIPS: Tweak Math.exp.

src/mips/codegen-mips.h

 // Copyright 2011 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 81 matching lines @@
                        Register result,
                        Label* call_runtime);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(StringCharLoadGenerator);
 };
 
 
 class MathExpGenerator : public AllStatic {
  public:
+  // Register input isn't modified. All other registers are clobbered.
   static void EmitMathExp(MacroAssembler* masm,
                           DoubleRegister input,
                           DoubleRegister result,
                           DoubleRegister double_scratch1,
                           DoubleRegister double_scratch2,
                           Register temp1,
                           Register temp2,
                           Register temp3);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MathExpGenerator);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_MIPS_CODEGEN_MIPS_H_