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[Bug tree-optimization/52459] [x86] loop vectorization performance very bad (worse than -O0) when using sse4.2 popcnt
- From: "M8R-ynb11d at mailinator dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Fri, 02 Mar 2012 07:11:47 +0000
- Subject: [Bug tree-optimization/52459] [x86] loop vectorization performance very bad (worse than -O0) when using sse4.2 popcnt
- Auto-submitted: auto-generated
- References: <bug-52459-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52459
--- Comment #1 from M8R-ynb11d at mailinator dot com 2012-03-02 07:11:47 UTC ---
Similar (but much slower) results when not using SSE and using the libgcc
library version of __builtin_popcount:
-O0: 22.55 secs
-O1: 20.57 secs
-O2: 22.48 secs
-Os: 22.81 secs
-O3: 45.17 secs