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[Bug middle-end/21137] Convert (a >> 2) & 1 != 0 into a & 4 != 0
- From: "phython at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 14 Aug 2005 21:56:53 -0000
- Subject: [Bug middle-end/21137] Convert (a >> 2) & 1 != 0 into a & 4 != 0
- References: <20050421004702.21137.kazu@gcc.gnu.org>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From phython at gcc dot gnu dot org 2005-08-14 21:56 -------
Actually, doing (a >> c1) & 2**c2 -> (a & (1<<c1+c2)) >> c1 looks worse, but
can be transformed into (a & (1<<c1+c2)) CMP c3 << c1. However, I haven't
figure out the details of the second transformation. There is a bug about it
though.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21137