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[Bug target/32593] Missed optimization of 'y = constant - x' operation
- From: "astrange at ithinksw dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 16 Feb 2008 18:16:44 -0000
- Subject: [Bug target/32593] Missed optimization of 'y = constant - x' operation
- References: <bug-32593-10175@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #3 from astrange at ithinksw dot com 2008-02-16 18:16 -------
Also, 'x >> 32 - y' can be transformed into 'x >> -y', since x86 only uses the
lowest 5 bits. I'm not sure about other targets.
Messing with the backend doesn't seem very popular these days. I guess I should
figure out how those parts work.
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32593