cvs commit: src/lib/msun/src s_cosf.c s_sinf.c

Bruce Evans bde at
Mon Nov 28 06:15:11 GMT 2005

bde         2005-11-28 06:15:10 UTC

  FreeBSD src repository

  Modified files:
    lib/msun/src         s_cosf.c s_sinf.c 
  Exploit skew-symmetry to avoid an operation: -sin(x-A) = sin(A-x).  This
  gives a tiny but hopefully always free optimization in the 2 quadrants
  to which it applies.  On Athlons, it reduces maximum latency by 4 cycles
  in these quadrants but has usually has a smaller effect on total time
  (typically ~2 cycles (~5%), but sometimes 8 cycles when the compiler
  generates poor code).
  Revision  Changes    Path
  1.14      +2 -2      src/lib/msun/src/s_cosf.c
  1.14      +2 -2      src/lib/msun/src/s_sinf.c

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