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[Bug tree-optimization/71026] Missing division optimizations
- From: "wdijkstr at arm dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Wed, 24 Aug 2016 14:47:20 +0000
- Subject: [Bug tree-optimization/71026] Missing division optimizations
- Auto-submitted: auto-generated
- References: <bug-71026-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71026
--- Comment #3 from Wilco <wdijkstr at arm dot com> ---
(In reply to ktkachov from comment #2)
> The transforms
>
> int f4(float x) { return (1.0f / x) < 0.0f; } // -> x < 0.0f
> int f5(float x) { return (x / 2.0f) <= 0.0f; } // -> x <= 0.0f
>
> can be done as match.pd patterns, no?
Note f5 is already transformed to (x * 0.5f) <= 0.0f even with -O2. The more
general form for that one is (X * C0) <= C1 -> X <= C1/C0.