[Bug tree-optimization/20219] Missed optimisation sin / tan --> cos

[uros at gcc dot gnu dot org]

--- Comment #4 from uros at gcc dot gnu dot org  2005-11-28 07:29 ---
Subject: Bug 20219

Author: uros
Date: Mon Nov 28 07:29:43 2005
New Revision: 107597

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=107597
Log:
PR middle-end/20219
* fold-const.c (fold binary) : Optimize 
sin(x)/tan(x) as cos(x) and tan(x)/sin(x) as 1.0/cos(x)
when flag_unsafe_math_optimizations is set and
we don't care about NaNs or Infinities.

Move x/expN(y) and x/pow(y,z) transformation into common
flag_unsafe_math_optimizations section.

testsuite/

* gcc.dg/builtins-20.c: Add checks for sin(x)/tan(x) and
tan(x)/sin(x) transformations.


Modified:
trunk/gcc/ChangeLog
trunk/gcc/fold-const.c
trunk/gcc/testsuite/ChangeLog
trunk/gcc/testsuite/gcc.dg/builtins-20.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20219

[Bug tree-optimization/20219] Missed optimisation sin / tan --> cos

[uros at kss-loka dot si]

--- Comment #3 from uros at kss-loka dot si  2005-11-28 07:20 ---
Reopened to ...


-- 

uros at kss-loka dot si changed:

   What|Removed |Added

 Status|RESOLVED|REOPENED
 Resolution|WONTFIX |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20219

[Bug tree-optimization/20219] Missed optimisation sin / tan --> cos

[uros at kss-loka dot si]

--- Additional Comments From uros at kss-loka dot si  2005-02-26 09:50 
---
Here is the patch to implement missing folds:
http://gcc.gnu.org/ml/gcc-patches/2004-03/msg01024.html

And here is the explanation why this transformation is not suitable for GCC even
with -ffast-math:
http://gcc.gnu.org/ml/gcc-patches/2004-03/msg01034.html

-- 
   What|Removed |Added

 Status|NEW |RESOLVED
 Resolution||WONTFIX


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20219

[Bug tree-optimization/20219] Missed optimisation sin / tan --> cos

[pinskia at gcc dot gnu dot org]

--- Additional Comments From pinskia at gcc dot gnu dot org  2005-02-26 
01:13 ---
Confirmed, nice catch.

-- 
   What|Removed |Added

 Status|UNCONFIRMED |NEW
  Component|rtl-optimization|tree-optimization
 Ever Confirmed||1
   Last reconfirmed|-00-00 00:00:00 |2005-02-26 01:13:02
   date||


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20219