[Bug tree-optimization/29985] New: sin (x) / cos (x) is not always folded to tan (x)

["ubizjak at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

This testcase shows the problem when compiled with -ffast-math:

double test1(double x)
{
        double y1, y2;

        y1 = sin(x);
        y2 = cos(x);

        return y1 / y2;
}

double test2(double x)
{
        return sin(x) / cos(x);
}

gcc -O2 -ffast-math:

_.099t.optimized:

;; Function test2 (test2)

Analyzing Edge Insertions.
test2 (x)
{
<bb 2>:
  return __builtin_tan (x) [tail call];

}



;; Function test1 (test1)

Analyzing Edge Insertions.
test1 (x)
{
<bb 2>:
  return sin (x) / cos (x);

}


-- 
           Summary: sin (x) / cos (x) is not always folded to tan (x)
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ubizjak at gmail dot com
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29985