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* [Bug middle-end/42961] [4.5/4.6 regression] IRA register preferencing bug
[not found] <bug-42961-4@http.gcc.gnu.org/bugzilla/>
@ 2010-12-16 13:03 ` rguenth at gcc dot gnu.org
2011-04-28 15:05 ` [Bug middle-end/42961] [4.5/4.6/4.7 " rguenth at gcc dot gnu.org
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: rguenth at gcc dot gnu.org @ 2010-12-16 13:03 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42961
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|4.5.2 |4.5.3
--- Comment #5 from Richard Guenther <rguenth at gcc dot gnu.org> 2010-12-16 13:02:54 UTC ---
GCC 4.5.2 is being released, adjusting target milestone.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug middle-end/42961] [4.5/4.6/4.7 regression] IRA register preferencing bug
[not found] <bug-42961-4@http.gcc.gnu.org/bugzilla/>
2010-12-16 13:03 ` [Bug middle-end/42961] [4.5/4.6 regression] IRA register preferencing bug rguenth at gcc dot gnu.org
@ 2011-04-28 15:05 ` rguenth at gcc dot gnu.org
2012-01-05 1:04 ` [Bug middle-end/42961] [4.5/4.6 " pinskia at gcc dot gnu.org
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: rguenth at gcc dot gnu.org @ 2011-04-28 15:05 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42961
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|4.5.3 |4.5.4
--- Comment #6 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-04-28 14:51:12 UTC ---
GCC 4.5.3 is being released, adjusting target milestone.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug middle-end/42961] [4.5/4.6 regression] IRA register preferencing bug
[not found] <bug-42961-4@http.gcc.gnu.org/bugzilla/>
2010-12-16 13:03 ` [Bug middle-end/42961] [4.5/4.6 regression] IRA register preferencing bug rguenth at gcc dot gnu.org
2011-04-28 15:05 ` [Bug middle-end/42961] [4.5/4.6/4.7 " rguenth at gcc dot gnu.org
@ 2012-01-05 1:04 ` pinskia at gcc dot gnu.org
2012-02-19 17:49 ` mikpe at it dot uu.se
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu.org @ 2012-01-05 1:04 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42961
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Known to work| |4.7.0
Summary|[4.5/4.6/4.7 regression] |[4.5/4.6 regression] IRA
|IRA register preferencing |register preferencing bug
|bug |
--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-01-05 01:02:51 UTC ---
This looks like it was fixed on the trunk, we no longer have any movss/movl.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug middle-end/42961] [4.5/4.6 regression] IRA register preferencing bug
[not found] <bug-42961-4@http.gcc.gnu.org/bugzilla/>
` (2 preceding siblings ...)
2012-01-05 1:04 ` [Bug middle-end/42961] [4.5/4.6 " pinskia at gcc dot gnu.org
@ 2012-02-19 17:49 ` mikpe at it dot uu.se
2012-07-02 11:05 ` rguenth at gcc dot gnu.org
2013-04-12 16:18 ` [Bug middle-end/42961] [4.6 " jakub at gcc dot gnu.org
5 siblings, 0 replies; 7+ messages in thread
From: mikpe at it dot uu.se @ 2012-02-19 17:49 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42961
--- Comment #8 from Mikael Pettersson <mikpe at it dot uu.se> 2012-02-19 17:43:07 UTC ---
The movss instructions were eliminated on trunk by Vladimir Makarov's "patch to
solve recent SPEC2000 degradation" in r178019:
http://gcc.gnu.org/ml/gcc-patches/2011-08/msg01954.html
http://gcc.gnu.org/ml/gcc-cvs/2011-08/msg01034.html
The code generation change at that point is:
--- pr42961.s-r178018 2012-02-19 18:22:46.000000000 +0100
+++ pr42961.s-r178019 2012-02-19 18:17:07.000000000 +0100
@@ -10,18 +10,17 @@
ucomiss %xmm2, %xmm2
jp .L7
jne .L7
- movss %xmm1, -4(%rsp)
.L2:
movl f(%rip), %eax
testl %eax, %eax
je .L4
- movss -4(%rsp), %xmm2
+ movaps %xmm1, %xmm2
.L4:
movaps %xmm2, %xmm0
ret
.L7:
movaps %xmm1, %xmm2
- movss %xmm0, -4(%rsp)
+ movaps %xmm0, %xmm1
jmp .L2
.cfi_endproc
.LFE0:
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug middle-end/42961] [4.5/4.6 regression] IRA register preferencing bug
[not found] <bug-42961-4@http.gcc.gnu.org/bugzilla/>
` (3 preceding siblings ...)
2012-02-19 17:49 ` mikpe at it dot uu.se
@ 2012-07-02 11:05 ` rguenth at gcc dot gnu.org
2013-04-12 16:18 ` [Bug middle-end/42961] [4.6 " jakub at gcc dot gnu.org
5 siblings, 0 replies; 7+ messages in thread
From: rguenth at gcc dot gnu.org @ 2012-07-02 11:05 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42961
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|4.5.4 |4.6.4
--- Comment #9 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-07-02 11:04:19 UTC ---
The 4.5 branch is being closed, adjusting target milestone.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug middle-end/42961] [4.6 regression] IRA register preferencing bug
[not found] <bug-42961-4@http.gcc.gnu.org/bugzilla/>
` (4 preceding siblings ...)
2012-07-02 11:05 ` rguenth at gcc dot gnu.org
@ 2013-04-12 16:18 ` jakub at gcc dot gnu.org
5 siblings, 0 replies; 7+ messages in thread
From: jakub at gcc dot gnu.org @ 2013-04-12 16:18 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42961
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution| |FIXED
Target Milestone|4.6.4 |4.7.0
--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-04-12 16:17:33 UTC ---
The 4.6 branch has been closed, fixed in GCC 4.7.0.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug middle-end/42961] New: [4.5 regression] IRA register preferencing bug
@ 2010-02-04 22:05 hubicka at gcc dot gnu dot org
2010-07-31 9:35 ` [Bug middle-end/42961] [4.5/4.6 " rguenth at gcc dot gnu dot org
0 siblings, 1 reply; 7+ messages in thread
From: hubicka at gcc dot gnu dot org @ 2010-02-04 22:05 UTC (permalink / raw)
To: gcc-bugs
For following testcase:
int e,f;
float
main(float d,float c)
{
float a;
float e;
if (e)
a=d, e=c;
else
a=c, c=e;
if (f)
e=a;
return e;
}
(it looks artifical, but all the moves are there just to make "a" to be only
source or destination of reg-reg move that is not that uncommon in real world
code)
we generate completely bogus:
main:
.LFB0:
.cfi_startproc
xorps %xmm2, %xmm2
movss %xmm1, -4(%rsp)
movl -4(%rsp), %eax
ucomiss %xmm2, %xmm2
jp .L7
je .L3
.L7:
movss %xmm0, -4(%rsp)
movl -4(%rsp), %eax
movaps %xmm1, %xmm2
.L3:
movl f(%rip), %edx
testl %edx, %edx
je .L4
movl %eax, -4(%rsp)
movss -4(%rsp), %xmm2
.L4:
movaps %xmm2, %xmm0
ret
instead of
main:
.LFB2:
movaps %xmm0, %xmm3
xorps %xmm0, %xmm0
movaps %xmm1, %xmm2
ucomiss %xmm0, %xmm0
jp .L2
je .L3
.L2:
movaps %xmm3, %xmm2
movaps %xmm1, %xmm0
.L3:
movl f(%rip), %eax
testl %eax, %eax
je .L4
movaps %xmm2, %xmm0
.L4:
rep
ret
.LFE2:
generated by GCC 4.3.2.
The problem is that IRA concludes wrong register preferencing:
a3 (r62,l0) best SSE_REGS, cover SSE_REGS
a2 (r61,l0) best SSE_FIRST_REG, cover SSE_REGS
a1 (r59,l0) best GENERAL_REGS, cover GENERAL_REGS
a0 (r58,l0) best SSE_FIRST_REG, cover SSE_REGS
this is because of movdf pattern having alternative for general regs.
This alternative is however useful primarily when the value is temporary for
mem-mem moves, and IRA should be able to work this out.
--
Summary: [4.5 regression] IRA register preferencing bug
Product: gcc
Version: 4.5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: hubicka at gcc dot gnu dot org
GCC host triplet: x86_64-linux
GCC target triplet: x86_64-linux
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42961
^ permalink raw reply [flat|nested] 7+ messages in thread
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[not found] <bug-42961-4@http.gcc.gnu.org/bugzilla/>
2010-12-16 13:03 ` [Bug middle-end/42961] [4.5/4.6 regression] IRA register preferencing bug rguenth at gcc dot gnu.org
2011-04-28 15:05 ` [Bug middle-end/42961] [4.5/4.6/4.7 " rguenth at gcc dot gnu.org
2012-01-05 1:04 ` [Bug middle-end/42961] [4.5/4.6 " pinskia at gcc dot gnu.org
2012-02-19 17:49 ` mikpe at it dot uu.se
2012-07-02 11:05 ` rguenth at gcc dot gnu.org
2013-04-12 16:18 ` [Bug middle-end/42961] [4.6 " jakub at gcc dot gnu.org
2010-02-04 22:05 [Bug middle-end/42961] New: [4.5 " hubicka at gcc dot gnu dot org
2010-07-31 9:35 ` [Bug middle-end/42961] [4.5/4.6 " rguenth at gcc dot gnu dot org
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