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[Bug optimization/12419] [3.3/3.4 Regression] Performace regression: poor optimization of const memory
- From: "steven at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 18 Dec 2003 17:29:56 -0000
- Subject: [Bug optimization/12419] [3.3/3.4 Regression] Performace regression: poor optimization of const memory
- References: <20030926105501.12419.aph@gcc.gnu.org>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From steven at gcc dot gnu dot org 2003-12-18 17:29 -------
The bug is still present on mainline...
(cc1 -O2 -fomit-frame-pointer-march=i686 -mtune=i686 ):
foo:
pushl %ebx
subl $8, %esp
movl a, %ebx
call f
movl a, %eax
addl $8, %esp
addl %eax, %ebx
movl %ebx, %eax
popl %ebx
ret
Just for fun, here's what tree-ssa makes of it
foo:
pushl %ebx
subl $8, %esp
movl a, %ebx
call f
addl $8, %esp
leal (%ebx,%ebx), %eax
popl %ebx
ret
--
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed|2003-09-27 06:36:21 |2003-12-18 17:29:55
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12419