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[Bug rtl-optimization/45617] optimize bit shift+compare at RTL level
- From: "jakub at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 13 Sep 2010 21:00:27 -0000
- Subject: [Bug rtl-optimization/45617] optimize bit shift+compare at RTL level
- References: <bug-45617-14164@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #2 from jakub at gcc dot gnu dot org 2010-09-13 21:00 -------
Subject: Bug 45617
Author: jakub
Date: Mon Sep 13 21:00:03 2010
New Revision: 164257
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=164257
Log:
PR rtl-optimization/45617
* combine.c (simplify_comparison): Optimize (X >> N) {>,>=,<,<=} C
even if low N bits of X aren't known to be zero.
* gcc.target/i386/pr45617.c: New test.
Added:
trunk/gcc/testsuite/gcc.target/i386/pr45617.c
Modified:
trunk/gcc/ChangeLog
trunk/gcc/combine.c
trunk/gcc/testsuite/ChangeLog
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45617