MD5 Code Optimizations

We modified the MD5 reference implementation to affect caching and to be optimized.

A compressed TAR file is available with these changes:

• Cache modifications (mddriver.c)
  • -l num : specify length of test block (used with -t, was DEFINE'd)
  • -c num : specify block repeat count (used with -t, was DEFIN'd)
  • -s : skip initialization of test block (to avoid first-touch of data)
  • -r : pseudo-random test block init (determines data-dependent perf)
  • -d : double-buffer test block (switch-off - forces data out of the cache)
• Performance optimizations (md5c.c)
  • use memset() and memcpy() (as suggested)
  • force state variables into registers
  • avoid Decode() for little-endians (Intel ix86, Dec Alpha)
  • avoid block copy for little-endians (Intel ix86, Dec Alpha)
  • unroll swap loop in Decode()
  • use optimized byte reordering code (C code that compiles better)
• Other changes
  • replace time() with getrusage()
  • change block length to 1M from 1K
  • print bits/sec
  • change LEN and COUNT in status print - they were incorrect

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Last modified Sept 24, 1997.