------- Comment #19 from rguenther at suse dot de 2008-10-15 13:18 ------- Subject: Re: [4.4 Regression] calculix gets wrong answer for -O1 -ffast-math
On Wed, 15 Oct 2008, dberlin at dberlin dot org wrote: > > > ------- Comment #18 from dberlin at gcc dot gnu dot org 2008-10-15 13:06 > ------- > Subject: Re: [4.4 Regression] calculix gets wrong answer for -O1 -ffast-math > > Making PRE do this is somewhat trivial. > Just extend fully_constant_expression to fold builtins, like it used > to, and it should just DTRT. It already does (I fixed that recently), but we only phi-translate during insertion and we don't insert for that case, as obviously there is no partial redundancy. Richard. > On Wed, Oct 15, 2008 at 5:38 AM, jakub at gcc dot gnu dot org > <[EMAIL PROTECTED]> wrote: > > > > > > ------- Comment #16 from jakub at gcc dot gnu dot org 2008-10-15 09:38 > > ------- > > After discussion with richi, I'd like to turn this into an enhancement > > request > > for 4.5 to extend PRE/SCCVN to be able to optimize that: > > # cn_43 = PHI <-1.0e+0(4), 1.0e+0(3)> > > D.1267_44 = __builtin_pow (cn_43, 2.0e+0); > > into a constant. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37449
