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[Bug tree-optimization/19940] Missed jump threading opportunity due to |.
- 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: 13 Feb 2005 18:59:10 -0000
- Subject: [Bug tree-optimization/19940] Missed jump threading opportunity due to |.
- References: <20050213183515.19940.kazu@cs.umass.edu>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From pinskia at gcc dot gnu dot org 2005-02-13 18:59 -------
Confirmed, related to PR 18832.
Note on PPC at least we don't really thread the jumps that well on the rtl level:
_foo:
or. r0,r4,r3
bne- cr0,L2
lis r2,ha16(_global)
ori r0,r3,1
lwz r2,lo16(_global)(r2)
cmpwi cr6,r0,0
cmpwi cr7,r2,0
beqlr- cr7
beqlr- cr6
L2:
b _bar
Now if we change all the unsigned char to _Bool we get the threaded jump:
_foo:
or. r0,r4,r3
bne- cr0,L2
lis r2,ha16(_global)
lwz r2,lo16(_global)(r2)
cmpwi cr7,r2,0
beqlr- cr7
L2:
b _bar
--
What |Removed |Added
----------------------------------------------------------------------------
BugsThisDependsOn| |18832
Status|UNCONFIRMED |NEW
Ever Confirmed| |1
Last reconfirmed|0000-00-00 00:00:00 |2005-02-13 18:59:10
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19940