Do integer mod via sum-of-digits technique. This benefits the date

src/arm/macro-assembler-arm.h

 // Copyright 2006-2009 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
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   // Get the number of least significant bits from a register
   void GetLeastBitsFromSmi(Register dst, Register src, int num_least_bits);
 
   // Uses VFP instructions to Convert a Smi to a double.
   void IntegerToDoubleConversionWithVFP3(Register inReg,
                                          Register outHighReg,
                                          Register outLowReg);
 
   // Count leading zeros in a 32 bit word.  On ARM5 and later it uses the clz
   // instruction.  On pre-ARM5 hardware this routine gives the wrong answer
-  // for 0 (31 instead of 32).
-  void CountLeadingZeros(Register source,
-                         Register scratch,
-                         Register zeros);
+  // for 0 (31 instead of 32).  Source and scratch can be the same in which case
+  // the source is clobbered.  Source and zeros can also be the same in which
+  // case scratch should be a different register.
+  void CountLeadingZeros(Register zeros,
+                         Register source,
+                         Register scratch);
 
   // ---------------------------------------------------------------------------
   // Runtime calls
 
   // Call a code stub.
   void CallStub(CodeStub* stub, Condition cond = al);
 
   // Call a code stub.
   void TailCallStub(CodeStub* stub, Condition cond = al);
 
@@ skipping 195 matching lines @@
 #define __FILE_LINE__ __FILE__ ":" CODE_COVERAGE_TOSTRING(__LINE__)
 #define ACCESS_MASM(masm) masm->stop(__FILE_LINE__); masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_MACRO_ASSEMBLER_ARM_H_