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[Bug c/38922] [4.3 Regression] Optimization regression in simple conditional code (js instead of cmov) 4.3 vs 4.1 and 3.4
- From: "rguenth at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 20 Jan 2009 09:04:34 -0000
- Subject: [Bug c/38922] [4.3 Regression] Optimization regression in simple conditional code (js instead of cmov) 4.3 vs 4.1 and 3.4
- References: <bug-38922-16413@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #2 from rguenth at gcc dot gnu dot org 2009-01-20 09:04 -------
4.4.0 is faster for me than 4.2 and 4.3 (4.3 is indeed slower than 4.2, but
my 3.4 (32bit only) is way slower than 4.4 (also 32bit)).
Note that performance of cmov heavily depends on the microarchitecture of your
CPU (I measured on a AMD K8).
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |missed-optimization
Known to fail| |4.3.2
Known to work| |3.4.6 4.4.0
Summary|Optimization regression in |[4.3 Regression]
|simple conditional code (js |Optimization regression in
|instead of cmov) 4.3 vs 4.1 |simple conditional code (js
|and 3.4 |instead of cmov) 4.3 vs 4.1
| |and 3.4
Target Milestone|--- |4.3.3
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38922