cvs commit: src/lib/msun/src e_rem_pio2f.c

[Bruce Evans]

bde         2005-10-09 04:29:08 UTC

  FreeBSD src repository

  Modified files:
    lib/msun/src         e_rem_pio2f.c 
  Log:
  Oops, the last-minute optimization in rev.1.8 wasn't a good idea.  The
  17+17+24 bit pi/2 must only be used when subtraction of the first 2
  terms in it from the arg is exact.  This happens iff the the arg in
  bits is one of the 2**17[-1] values on each side of (float)(pi/2).
  
  Revert to the algorithm in rev.1.7 and only fix its threshold for using
  the 3-term pi/2.  Use the threshold that maximizes the number of values
  for which the 3-term pi/2 is used, subject to not changing the algorithm
  for comparing with the threshold.  The 3-term pi/2 ends up being used
  for about half of its usable range (about 64K values on each side).
  
  Revision  Changes    Path
  1.10      +18 -7     src/lib/msun/src/e_rem_pio2f.c