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[Bug tree-optimization/14886] strength reduction on floating point
- From: "dje at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 11 Jan 2006 02:20:32 -0000
- Subject: [Bug tree-optimization/14886] strength reduction on floating point
- References: <bug-14886-1057@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #5 from dje at gcc dot gnu dot org 2006-01-11 02:20 -------
What is the specific testcase compiled by XLC? What version of XLC? And what
options were used?
I cannot reproduce strength reduction of a floating point multiply to floating
point adds with a testcase that uses a function call instead of a volatile asm.
In general FP strength reduction is unsafe. This could be implemented for GCC
when -ffast-math is enabled, but I would like to understand exactly when XLC
thinks it is safe to do this, if it indeed still performs the transformation.
--
dje at gcc dot gnu dot org changed:
What |Removed |Added
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CC| |dje at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14886