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[Bug optimization/13219] -fgcse pessimizes double complex calculation
- From: "pinskia at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 28 Nov 2003 17:33:43 -0000
- Subject: [Bug optimization/13219] -fgcse pessimizes double complex calculation
- References: <20031128171739.13219.coyote@coyotegulch.com>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From pinskia at gcc dot gnu dot org 2003-11-28 17:33 -------
I can confirm this on the mainline on powerpc-apple-darwin (where there are plenty of registers):
-O1:
fmul f13,f12,f12
fmsub f13,f11,f11,f13
fmul f0,f11,f12
fadd f0,f0,f0
fadd f11,f13,f8
fadd f12,f0,f9
fmul f0,f12,f12
fmadd f0,f11,f11,f0
fcmpu cr7,f0,f10
cror 30,29,30
beq- cr7,L3
addi r2,r2,1
cmpwi cr7,r2,255
ble+ cr7,L7
-O1 -fgcse:
fmul f0,f12,f12
fmsub f0,f11,f11,f0
fmul f13,f11,f12
fadd f13,f13,f13
fadd f0,f0,f8
fadd f13,f13,f9
fmr f11,f0
fmr f12,f13
fmul f13,f13,f13
fmadd f0,f0,f0,f13
fcmpu cr7,f0,f10
cror 30,29,30
beq- cr7,L3
addi r2,r2,1
cmpwi cr7,r2,255
ble+ cr7,L7
See the extra fmr that is the problem.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Component|c |optimization
Ever Confirmed| |1
Keywords| |pessimizes-code
Last reconfirmed|0000-00-00 00:00:00 |2003-11-28 17:33:42
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13219