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* [Bug tree-optimization/44669] New: ccp or similar passes aren't run after cunroll
@ 2010-06-25 16:25 jakub at gcc dot gnu dot org
2010-06-25 16:26 ` [Bug tree-optimization/44669] " jakub at gcc dot gnu dot org
2010-06-25 20:56 ` rguenth at gcc dot gnu dot org
0 siblings, 2 replies; 3+ messages in thread
From: jakub at gcc dot gnu dot org @ 2010-06-25 16:25 UTC (permalink / raw)
To: gcc-bugs
! { dg-options "-O2 -funroll-loops" }
function foo (b)
character (len=1) :: b(4)
logical :: foo
foo = any (b .ne. (/"1","2","3","4"/))
end
results in horrible code:
movzbl .LC0(%rip), %edx
movl $1, %eax
cmpb %dl, (%rdi)
jne .L2
movzbl .LC1(%rip), %ecx
cmpb %cl, 1(%rdi)
jne .L2
movzbl .LC2(%rip), %esi
cmpb %sil, 2(%rdi)
jne .L2
movzbl .LC3(%rip), %r8d
cmpb %r8b, 3(%rdi)
setne %al
movzbl %al, %eax
.L2:
rep
ret
because nothing optimizes the constant array reads after cunroll.
If I schedule another pass_ccp right after pass_complete_unroll, much better
code is generated:
cmpb $49, (%rdi)
movl $1, %eax
jne .L2
cmpb $50, 1(%rdi)
jne .L2
cmpb $51, 2(%rdi)
jne .L2
xorl %eax, %eax
cmpb $52, 3(%rdi)
setne %al
.L2:
rep
ret
--
Summary: ccp or similar passes aren't run after cunroll
Product: gcc
Version: 4.6.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P3
Component: tree-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: jakub at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44669
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug tree-optimization/44669] ccp or similar passes aren't run after cunroll
2010-06-25 16:25 [Bug tree-optimization/44669] New: ccp or similar passes aren't run after cunroll jakub at gcc dot gnu dot org
@ 2010-06-25 16:26 ` jakub at gcc dot gnu dot org
2010-06-25 20:56 ` rguenth at gcc dot gnu dot org
1 sibling, 0 replies; 3+ messages in thread
From: jakub at gcc dot gnu dot org @ 2010-06-25 16:26 UTC (permalink / raw)
To: gcc-bugs
--
jakub at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|--- |4.6.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44669
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug tree-optimization/44669] ccp or similar passes aren't run after cunroll
2010-06-25 16:25 [Bug tree-optimization/44669] New: ccp or similar passes aren't run after cunroll jakub at gcc dot gnu dot org
2010-06-25 16:26 ` [Bug tree-optimization/44669] " jakub at gcc dot gnu dot org
@ 2010-06-25 20:56 ` rguenth at gcc dot gnu dot org
1 sibling, 0 replies; 3+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2010-06-25 20:56 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from rguenth at gcc dot gnu dot org 2010-06-25 20:56 -------
Confirmed.
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |rguenth at gcc dot gnu dot
| |org
Severity|normal |enhancement
Status|UNCONFIRMED |NEW
Ever Confirmed|0 |1
Last reconfirmed|0000-00-00 00:00:00 |2010-06-25 20:56:34
date| |
Target Milestone|4.6.0 |---
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44669
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2010-06-25 20:56 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2010-06-25 16:25 [Bug tree-optimization/44669] New: ccp or similar passes aren't run after cunroll jakub at gcc dot gnu dot org
2010-06-25 16:26 ` [Bug tree-optimization/44669] " jakub at gcc dot gnu dot org
2010-06-25 20:56 ` rguenth at gcc dot gnu dot org
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