cvs commit: src/lib/msun/bsdsrc b_tgamma.c

[Bruce Evans]

bde         2007-05-02 13:49:28 UTC

  FreeBSD src repository

  Modified files:
    lib/msun/bsdsrc      b_tgamma.c 
  Log:
  Document (in a comment) the current (slightly broken) handling of special
  values in more detail, and change the style of this comment to be closer
  to fdlibm and C99:
  - tgamma(-Inf) was undocumented and is wrong (+Inf, should be NaN)
  - tgamma(negative integer) is as intended (+Inf) but not best for IEEE-754
    (NaN)
  - tgamma(-0) was documented as being wrong (+Inf) but was correct (-Inf)
  - documentation of setting of exceptions (overflow, etc.) was more
    complete here than in most of libm, but was further from matching
    the actual setting than in most of libm, due to various bugs here
    (primarily, always evaluating +Inf one/zero and getting unwanted
    divide-by-zero exceptions from this).  Now the actual behaviour with
    gcc -O0 is documented.  Optimization still breaks setting of exceptions
    all over libm, so nothing can depend on this working.
  - tgamma(NaN)'s exception was documented as being wrong (invalid) but was
    correct (no exception with IEEEish NaNs).
  
  Finish (?) rev.1.5.  gamma was not renamed to tgamma in one place.
  
  Finish (?) rev.1.6.  errno.h was not completely removed.
  
  Revision  Changes    Path
  1.8       +9 -6      src/lib/msun/bsdsrc/b_tgamma.c