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* [Bug middle-end/60313] New: volatile prevents optimizing logic on memory
@ 2014-02-22 1:38 hjl.tools at gmail dot com
2014-02-22 2:19 ` [Bug middle-end/60313] " glisse at gcc dot gnu.org
2014-02-22 4:14 ` pinskia at gcc dot gnu.org
0 siblings, 2 replies; 3+ messages in thread
From: hjl.tools at gmail dot com @ 2014-02-22 1:38 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60313
Bug ID: 60313
Summary: volatile prevents optimizing logic on memory
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: hjl.tools at gmail dot com
[hjl@gnu-6 rib86-1]$ cat q6.i
volatile unsigned char result;
void foo (void)
{
result |= 0x1;
}
[hjl@gnu-6 rib86-1]$ gcc -S -O2 q6.i
[hjl@gnu-6 rib86-1]$ cat q6.s
.file "q6.i"
.text
.p2align 4,,15
.globl foo
.type foo, @function
foo:
.LFB0:
.cfi_startproc
movzbl result(%rip), %eax
orl $1, %eax
movb %al, result(%rip)
ret
.cfi_endproc
.LFE0:
.size foo, .-foo
Remove volatile leads to:
foo:
.LFB0:
.cfi_startproc
orb $1, result(%rip)
ret
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug middle-end/60313] volatile prevents optimizing logic on memory
2014-02-22 1:38 [Bug middle-end/60313] New: volatile prevents optimizing logic on memory hjl.tools at gmail dot com
@ 2014-02-22 2:19 ` glisse at gcc dot gnu.org
2014-02-22 4:14 ` pinskia at gcc dot gnu.org
1 sibling, 0 replies; 3+ messages in thread
From: glisse at gcc dot gnu.org @ 2014-02-22 2:19 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60313
--- Comment #1 from Marc Glisse <glisse at gcc dot gnu.org> ---
Dup of PR 50677 ?
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug middle-end/60313] volatile prevents optimizing logic on memory
2014-02-22 1:38 [Bug middle-end/60313] New: volatile prevents optimizing logic on memory hjl.tools at gmail dot com
2014-02-22 2:19 ` [Bug middle-end/60313] " glisse at gcc dot gnu.org
@ 2014-02-22 4:14 ` pinskia at gcc dot gnu.org
1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu.org @ 2014-02-22 4:14 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60313
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution|--- |DUPLICATE
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Yes a dup.
*** This bug has been marked as a duplicate of bug 50677 ***
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2014-02-22 4:14 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2014-02-22 1:38 [Bug middle-end/60313] New: volatile prevents optimizing logic on memory hjl.tools at gmail dot com
2014-02-22 2:19 ` [Bug middle-end/60313] " glisse at gcc dot gnu.org
2014-02-22 4:14 ` pinskia at gcc dot gnu.org
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