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* [Bug target/17959] -mpowerpc64 can cause worse code than without it
[not found] <bug-17959-6528@http.gcc.gnu.org/bugzilla/>
@ 2006-03-30 17:47 ` sayle at gcc dot gnu dot org
2006-03-30 21:35 ` roger at eyesopen dot com
1 sibling, 0 replies; 4+ messages in thread
From: sayle at gcc dot gnu dot org @ 2006-03-30 17:47 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from sayle at gcc dot gnu dot org 2006-03-30 17:47 -------
Subject: Bug 17959
Author: sayle
Date: Thu Mar 30 17:47:48 2006
New Revision: 112543
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=112543
Log:
PR target/17959
* expr.c (emit_group_store): Optimize group stores into a pseudo
register by using a paradoxical subreg to initialize the destination
if the first or last member of the group specifies a "low part".
Modified:
trunk/gcc/ChangeLog
trunk/gcc/expr.c
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17959
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/17959] -mpowerpc64 can cause worse code than without it
[not found] <bug-17959-6528@http.gcc.gnu.org/bugzilla/>
2006-03-30 17:47 ` [Bug target/17959] -mpowerpc64 can cause worse code than without it sayle at gcc dot gnu dot org
@ 2006-03-30 21:35 ` roger at eyesopen dot com
1 sibling, 0 replies; 4+ messages in thread
From: roger at eyesopen dot com @ 2006-03-30 21:35 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from roger at eyesopen dot com 2006-03-30 21:35 -------
This is now be fixed on mainline. With -mpowerpc64, we now generate:
_div16:
rldimi 3,4,0,32
srdi 4,3,4
srdi 3,3,36
blr
--
roger at eyesopen dot com changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution| |FIXED
Target Milestone|--- |4.2.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17959
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/17959] New: -mpowerpc64 can cause worse code than without it
@ 2004-10-12 23:01 pinskia at gcc dot gnu dot org
2004-10-12 23:03 ` [Bug target/17959] " pinskia at gcc dot gnu dot org
2004-11-28 8:27 ` amodra at bigpond dot net dot au
0 siblings, 2 replies; 4+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-10-12 23:01 UTC (permalink / raw)
To: gcc-bugs
unsigned long long div16(unsigned long long n) { return n / 16; }
Without -mpowerpc64:
_div16:
slwi r0,r3,28
srwi r4,r4,4
or r4,r0,r4
srwi r3,r3,4
blr
With:
_div16:
li r0,0
rldimi r0,r3,32,0
rldimi r0,r4,0,32
srdi r4,r0,4
srdi r3,r0,36
blr
--
Summary: -mpowerpc64 can cause worse code than without it
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P2
Component: target
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: pinskia at gcc dot gnu dot org
CC: gcc-bugs at gcc dot gnu dot org
GCC target triplet: powerpc-darwin
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17959
^ permalink raw reply [flat|nested] 4+ messages in thread
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[not found] <bug-17959-6528@http.gcc.gnu.org/bugzilla/>
2006-03-30 17:47 ` [Bug target/17959] -mpowerpc64 can cause worse code than without it sayle at gcc dot gnu dot org
2006-03-30 21:35 ` roger at eyesopen dot com
2004-10-12 23:01 [Bug target/17959] New: " pinskia at gcc dot gnu dot org
2004-10-12 23:03 ` [Bug target/17959] " pinskia at gcc dot gnu dot org
2004-11-28 8:27 ` amodra at bigpond dot net dot au
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