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Re: fast-math optimization question
- From: "Joseph S. Myers" <joseph at codesourcery dot com>
- To: Steve Ellcey <sellcey at mips dot com>
- Cc: Andrew Pinski <pinskia at gmail dot com>, GCC Mailing List <gcc at gcc dot gnu dot org>
- Date: Thu, 9 Oct 2014 19:50:56 +0000
- Subject: Re: fast-math optimization question
- Authentication-results: sourceware.org; auth=none
- References: <10940e4b-0c5c-4a2a-9432-6385e9590fb4 at BAMAIL02 dot ba dot imgtec dot org> <CA+=Sn1mkOCmPxPmn-RYkE+CJBrQ=8U7O07RUj8wwc6KyuXzrJQ at mail dot gmail dot com> <1412879523 dot 28410 dot 133 dot camel at ubuntu-sellcey>
On Thu, 9 Oct 2014, Steve Ellcey wrote:
> Do you know which pass does the simple
> '(float)function((double)float_val)' demotion? Maybe that would be a
> good place to extend things.
convert.c does such transformations. Maybe the transformations in there
could move to the match-and-simplify infrastructure - convert.c is not a
particularly good place for optimization, and having similar
transformations scattered around (fold-const, convert.c, front ends, SSA
optimizers) isn't helpful; hopefully match-and-simplify will allow some
unification of this sort of optimization.
Joseph S. Myers