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* [Bug tree-optimization/32824] New: Missed reduction vectorizer after store to global is LIM'd
@ 2007-07-19 16:56 pinskia at gcc dot gnu dot org
2007-07-19 18:09 ` [Bug tree-optimization/32824] " dorit at gcc dot gnu dot org
` (9 more replies)
0 siblings, 10 replies; 11+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2007-07-19 16:56 UTC (permalink / raw)
To: gcc-bugs
Testcase:
int a[16*100];
int e;
float f(void)
{
int i;
for(i = 0;i<16*100;i++)
e += a[i];
}
rt.c:7: note: not vectorized: unsupported use in stmt.
If I manually LIM'd e, then this is vectorized.
--
Summary: Missed reduction vectorizer after store to global is
LIM'd
Product: gcc
Version: 4.3.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P3
Component: tree-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: pinskia at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32824
^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug tree-optimization/32824] Missed reduction vectorizer after store to global is LIM'd
2007-07-19 16:56 [Bug tree-optimization/32824] New: Missed reduction vectorizer after store to global is LIM'd pinskia at gcc dot gnu dot org
@ 2007-07-19 18:09 ` dorit at gcc dot gnu dot org
2007-07-19 18:14 ` pinskia at gcc dot gnu dot org
` (8 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: dorit at gcc dot gnu dot org @ 2007-07-19 18:09 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from dorit at gcc dot gnu dot org 2007-07-19 18:09 -------
I think this is similar to PR19347?
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32824
^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug tree-optimization/32824] Missed reduction vectorizer after store to global is LIM'd
2007-07-19 16:56 [Bug tree-optimization/32824] New: Missed reduction vectorizer after store to global is LIM'd pinskia at gcc dot gnu dot org
2007-07-19 18:09 ` [Bug tree-optimization/32824] " dorit at gcc dot gnu dot org
@ 2007-07-19 18:14 ` pinskia at gcc dot gnu dot org
2007-07-19 18:28 ` dorit at gcc dot gnu dot org
` (7 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2007-07-19 18:14 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from pinskia at gcc dot gnu dot org 2007-07-19 18:14 -------
(In reply to comment #1)
> I think this is similar to PR19347?
It is not because LIM does its work, IR right before the vectorizer:
<bb 3>:
# ivtmp.31_17 = PHI <ivtmp.31_18(4), 1600(2)>
# e_lsm.30_1 = PHI <e_lsm.30_13(4), e_lsm.30_8(2)>
# i_14 = PHI <i_7(4), 0(2)>
D.2248_4 = a[i_14];
e.1_5 = e_lsm.30_1;
e.2_6 = D.2248_4 + e.1_5;
e_lsm.30_13 = e.2_6;
i_7 = i_14 + 1;
ivtmp.31_18 = ivtmp.31_17 - 1;
if (ivtmp.31_18 != 0)
There are no loads from e in the loop.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32824
^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug tree-optimization/32824] Missed reduction vectorizer after store to global is LIM'd
2007-07-19 16:56 [Bug tree-optimization/32824] New: Missed reduction vectorizer after store to global is LIM'd pinskia at gcc dot gnu dot org
2007-07-19 18:09 ` [Bug tree-optimization/32824] " dorit at gcc dot gnu dot org
2007-07-19 18:14 ` pinskia at gcc dot gnu dot org
@ 2007-07-19 18:28 ` dorit at gcc dot gnu dot org
2007-07-24 8:59 ` dorit at gcc dot gnu dot org
` (6 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: dorit at gcc dot gnu dot org @ 2007-07-19 18:28 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from dorit at gcc dot gnu dot org 2007-07-19 18:28 -------
ah, I misunderstood you - when you wrote before that you manually LIM'd e I
assumed it was because LIM didn't work. I see that the problem is with the
"garbage" that LIM leaves behind:
pr32824.c:6: note: Analyze phi: e_lsm.30_1 = PHI <e_lsm.30_13(4),
e_lsm.30_8(2)pr32824.c:6: note: Unknown def-use cycle pattern.
...
pr32824.c:6: note: def_stmt: e_lsm.30_1 = PHI <e_lsm.30_13(4), e_lsm.30_8(2)>
pr32824.c:6: note: Unsupported pattern.
pr32824.c:6: note: not vectorized: unsupported use in stmt.
We may have a PR for cleaning up redundant phis (or teach the vectorizer to
ignore them) - I'll try to look for it.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32824
^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug tree-optimization/32824] Missed reduction vectorizer after store to global is LIM'd
2007-07-19 16:56 [Bug tree-optimization/32824] New: Missed reduction vectorizer after store to global is LIM'd pinskia at gcc dot gnu dot org
` (2 preceding siblings ...)
2007-07-19 18:28 ` dorit at gcc dot gnu dot org
@ 2007-07-24 8:59 ` dorit at gcc dot gnu dot org
2007-08-14 20:48 ` dorit at gcc dot gnu dot org
` (5 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: dorit at gcc dot gnu dot org @ 2007-07-24 8:59 UTC (permalink / raw)
To: gcc-bugs
------- Comment #4 from dorit at gcc dot gnu dot org 2007-07-24 08:59 -------
Just for the record - as we discussed last week, there are two ways to solve
this problem - either have LIM leave behind it cleaner code (smthing like
copy-prop + dce to eliminate the extra copy stmts), or improve the reduction
detection code in the vectorizer, which is something we want to do anyway.
Actually this looks like a duplicate of PR25621.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32824
^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug tree-optimization/32824] Missed reduction vectorizer after store to global is LIM'd
2007-07-19 16:56 [Bug tree-optimization/32824] New: Missed reduction vectorizer after store to global is LIM'd pinskia at gcc dot gnu dot org
` (3 preceding siblings ...)
2007-07-24 8:59 ` dorit at gcc dot gnu dot org
@ 2007-08-14 20:48 ` dorit at gcc dot gnu dot org
2010-02-26 13:21 ` manu at gcc dot gnu dot org
` (4 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: dorit at gcc dot gnu dot org @ 2007-08-14 20:48 UTC (permalink / raw)
To: gcc-bugs
------- Comment #5 from dorit at gcc dot gnu dot org 2007-08-14 20:47 -------
Additional testcases:
(1) see loop in lines 23 and 32 in
http://gcc.gnu.org/ml/gcc-help/2007-08/msg00171.html
(2)
> SUBROUTINE SUSCEP(L,Iz)
> IMPLICIT NONE
> INTEGER L , Iz(L,L) , iznum, ix, iy
> iznum = 0
> DO ix = 1 , L
> DO iy = 1 , L
> iznum = iznum + Iz(iy,ix)
> ENDDO
> ENDDO
> PRINT* iznum
> END subroutine
> end
>
The above is a slightly modified testcase taken from Polyhedron test suite
(ac.f90).
We get:
b.f90:6: note: Analyze phi: iznum_lsm.74_31 = PHI <iznum_lsm.74_32(4),
iznum_lsm.74_12(6)>
b.f90:6: note: reduction: not commutative/associative: iznum.10_37
tobias2b.f90:6: note: Unknown def-use cycle pattern.
...
b.f90:6: note: worklist: examine stmt: iznum.9_36 = iznum_lsm.74_31
b.f90:6: note: vect_is_simple_use: operand iznum_lsm.74_31
b.f90:6: note: def_stmt: iznum_lsm.74_31 = PHI <iznum_lsm.74_32(4),
iznum_lsm.74_12(6)>
b.f90:6: note: Unsupported pattern.
b.f90:6: note: not vectorized: unsupported use in stmt.
2b.f90:6: note: unexpected pattern.
This happens because we get the following pattern:
# iznum_lsm.74_31 = PHI <iznum_lsm.74_32(4), iznum_lsm.74_12(6)>
...
iznum.9_36 = iznum_lsm.74_31;
iznum.10_37 = D.1420_35 + iznum.9_36;
iznum_lsm.74_12 = iznum.10_37;
...
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32824
^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug tree-optimization/32824] Missed reduction vectorizer after store to global is LIM'd
2007-07-19 16:56 [Bug tree-optimization/32824] New: Missed reduction vectorizer after store to global is LIM'd pinskia at gcc dot gnu dot org
` (4 preceding siblings ...)
2007-08-14 20:48 ` dorit at gcc dot gnu dot org
@ 2010-02-26 13:21 ` manu at gcc dot gnu dot org
2010-03-17 17:59 ` burnus at gcc dot gnu dot org
` (3 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: manu at gcc dot gnu dot org @ 2010-02-26 13:21 UTC (permalink / raw)
To: gcc-bugs
------- Comment #6 from manu at gcc dot gnu dot org 2010-02-26 13:20 -------
*** Bug 43184 has been marked as a duplicate of this bug. ***
--
manu at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |changpeng dot fang at amd
| |dot com
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32824
^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug tree-optimization/32824] Missed reduction vectorizer after store to global is LIM'd
2007-07-19 16:56 [Bug tree-optimization/32824] New: Missed reduction vectorizer after store to global is LIM'd pinskia at gcc dot gnu dot org
` (5 preceding siblings ...)
2010-02-26 13:21 ` manu at gcc dot gnu dot org
@ 2010-03-17 17:59 ` burnus at gcc dot gnu dot org
2010-03-17 21:22 ` changpeng dot fang at amd dot com
` (2 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: burnus at gcc dot gnu dot org @ 2010-03-17 17:59 UTC (permalink / raw)
To: gcc-bugs
------- Comment #7 from burnus at gcc dot gnu dot org 2010-03-17 17:58 -------
Patch by Changpeng, which has been approved for 4.6 Stage 1 and moves the
"pass_lim" up;
http://gcc.gnu.org/ml/gcc-patches/2010-03/msg00775.html
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32824
^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug tree-optimization/32824] Missed reduction vectorizer after store to global is LIM'd
2007-07-19 16:56 [Bug tree-optimization/32824] New: Missed reduction vectorizer after store to global is LIM'd pinskia at gcc dot gnu dot org
` (6 preceding siblings ...)
2010-03-17 17:59 ` burnus at gcc dot gnu dot org
@ 2010-03-17 21:22 ` changpeng dot fang at amd dot com
2010-04-06 19:20 ` spop at gcc dot gnu dot org
2010-04-11 5:45 ` spop at gcc dot gnu dot org
9 siblings, 0 replies; 11+ messages in thread
From: changpeng dot fang at amd dot com @ 2010-03-17 21:22 UTC (permalink / raw)
To: gcc-bugs
------- Comment #8 from changpeng dot fang at amd dot com 2010-03-17 21:22 -------
Created an attachment (id=20133)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=20133&action=view)
patch with the testcase
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32824
^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug tree-optimization/32824] Missed reduction vectorizer after store to global is LIM'd
2007-07-19 16:56 [Bug tree-optimization/32824] New: Missed reduction vectorizer after store to global is LIM'd pinskia at gcc dot gnu dot org
` (7 preceding siblings ...)
2010-03-17 21:22 ` changpeng dot fang at amd dot com
@ 2010-04-06 19:20 ` spop at gcc dot gnu dot org
2010-04-11 5:45 ` spop at gcc dot gnu dot org
9 siblings, 0 replies; 11+ messages in thread
From: spop at gcc dot gnu dot org @ 2010-04-06 19:20 UTC (permalink / raw)
To: gcc-bugs
------- Comment #9 from spop at gcc dot gnu dot org 2010-04-06 19:20 -------
Subject: Bug 32824
Author: spop
Date: Tue Apr 6 19:19:41 2010
New Revision: 158018
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=158018
Log:
Fix PR32824.
2010-04-06 Changpeng Fang <changpeng.fang@amd.com>
PR middle-end/32824
* passes.c (init_optimization_passes): Move pass_lim before
pass_copy_prop and pass_dce_loop.
* gcc.dg/vect/pr32824: New.
Added:
trunk/gcc/testsuite/gcc.dg/vect/pr32824.c
Modified:
trunk/gcc/ChangeLog
trunk/gcc/passes.c
trunk/gcc/testsuite/ChangeLog
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32824
^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug tree-optimization/32824] Missed reduction vectorizer after store to global is LIM'd
2007-07-19 16:56 [Bug tree-optimization/32824] New: Missed reduction vectorizer after store to global is LIM'd pinskia at gcc dot gnu dot org
` (8 preceding siblings ...)
2010-04-06 19:20 ` spop at gcc dot gnu dot org
@ 2010-04-11 5:45 ` spop at gcc dot gnu dot org
9 siblings, 0 replies; 11+ messages in thread
From: spop at gcc dot gnu dot org @ 2010-04-11 5:45 UTC (permalink / raw)
To: gcc-bugs
------- Comment #10 from spop at gcc dot gnu dot org 2010-04-11 05:45 -------
Fixed.
--
spop at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |FIXED
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32824
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2007-07-19 16:56 [Bug tree-optimization/32824] New: Missed reduction vectorizer after store to global is LIM'd pinskia at gcc dot gnu dot org
2007-07-19 18:09 ` [Bug tree-optimization/32824] " dorit at gcc dot gnu dot org
2007-07-19 18:14 ` pinskia at gcc dot gnu dot org
2007-07-19 18:28 ` dorit at gcc dot gnu dot org
2007-07-24 8:59 ` dorit at gcc dot gnu dot org
2007-08-14 20:48 ` dorit at gcc dot gnu dot org
2010-02-26 13:21 ` manu at gcc dot gnu dot org
2010-03-17 17:59 ` burnus at gcc dot gnu dot org
2010-03-17 21:22 ` changpeng dot fang at amd dot com
2010-04-06 19:20 ` spop at gcc dot gnu dot org
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