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* [Bug tree-optimization/50162] New: Wrong vectorization
@ 2011-08-23 8:03 ubizjak at gmail dot com
2011-08-23 8:14 ` [Bug tree-optimization/50162] [4.7 Regression] " ubizjak at gmail dot com
` (10 more replies)
0 siblings, 11 replies; 12+ messages in thread
From: ubizjak at gmail dot com @ 2011-08-23 8:03 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50162
Bug #: 50162
Summary: Wrong vectorization
Classification: Unclassified
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: ubizjak@gmail.com
Target: x86
Following testcase results in wrong vectorization:
--cut here--
double a[256];
int b[256];
unsigned short c[256];
extern long lrint (double);
void bar(void)
{
int i;
for (i=0; i<256; ++i)
{
b[i] = lrint (a[i]);
c[i] += c[i];
}
}
--cut here--
gcc -O2 -ffast-math -ftree-vectorize -m32 -msse2 -mfpmath=sse
.L2:
cvtpd2dq a+16(,%eax,4), %xmm0
cvtpd2dq a(,%eax,4), %xmm1
cvtpd2dq a+32(,%eax,4), %xmm2
punpcklqdq %xmm0, %xmm1
punpcklqdq %xmm2, %xmm0
movdqa %xmm0, b+16(%eax,%eax)
movdqa c(%eax), %xmm0
paddw %xmm0, %xmm0
movdqa %xmm1, b(%eax,%eax)
movdqa %xmm0, c(%eax)
addl $16, %eax
cmpl $512, %eax
jne .L2
One cvtpd2dq is missing.
4.6.1. compiles to:
.L2:
cvtpd2dq a+16(,%eax,4), %xmm0
cvtpd2dq a(,%eax,4), %xmm1
cvtpd2dq a+48(,%eax,4), %xmm2
punpcklqdq %xmm0, %xmm1
cvtpd2dq a+32(,%eax,4), %xmm0
punpcklqdq %xmm2, %xmm0
movdqa %xmm0, b+16(%eax,%eax)
movdqa c(%eax), %xmm0
paddw %xmm0, %xmm0
movdqa %xmm1, b(%eax,%eax)
movdqa %xmm0, c(%eax)
addl $16, %eax
cmpl $512, %eax
jne .L2
The problem is already in .optimized tree dump:
vect_var_.13_22 = MEM[symbol: a, index: ivtmp.41_17, step: 4, offset: 0B];
vect_var_.14_24 = MEM[symbol: a, index: ivtmp.41_17, step: 4, offset: 16B];
vect_var_.15_26 = MEM[symbol: a, index: ivtmp.41_17, step: 4, offset: 32B];
vect_var_.17_29 = __builtin_ia32_vec_pack_sfix (vect_var_.13_22,
vect_var_.14_24);
vect_var_.17_30 = __builtin_ia32_vec_pack_sfix (vect_var_.14_24,
vect_var_.15_26);
MEM[symbol: b, index: ivtmp.41_17, step: 2, offset: 0B] = vect_var_.17_29;
MEM[symbol: b, index: ivtmp.41_17, step: 2, offset: 16B] = vect_var_.17_30;
vect_var_.26_38 = MEM[symbol: c, index: ivtmp.41_17, offset: 0B];
vect_var_.27_39 = vect_var_.26_38 + vect_var_.26_38;
MEM[symbol: c, index: ivtmp.41_17, offset: 0B] = vect_var_.27_39;
Please note, there is no access to offset 48B.
Gcc 4.6.1 generates:
vect_var_.39 = __builtin_ia32_vec_pack_sfix (MEM[symbol: a, index: ivtmp.69,
step: 4], MEM[symbol: a, index: ivtmp.69, step: 4, offset: 16]);
vect_var_.77 = __builtin_ia32_vec_pack_sfix (MEM[symbol: a, index: ivtmp.69,
step: 4, offset: 32], MEM[symbol: a, index: ivtmp.69, step: 4, offset: 48]);
MEM[symbol: b, index: ivtmp.69, step: 2] = vect_var_.39;
MEM[symbol: b, index: ivtmp.69, step: 2, offset: 16] = vect_var_.77;
vect_var_.52 = MEM[symbol: c, index: ivtmp.69];
MEM[symbol: c, index: ivtmp.69] = [plus_expr] vect_var_.52 + vect_var_.52;
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug tree-optimization/50162] [4.7 Regression] Wrong vectorization
2011-08-23 8:03 [Bug tree-optimization/50162] New: Wrong vectorization ubizjak at gmail dot com
@ 2011-08-23 8:14 ` ubizjak at gmail dot com
2011-08-23 8:53 ` rguenth at gcc dot gnu.org
` (9 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: ubizjak at gmail dot com @ 2011-08-23 8:14 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50162
Uros Bizjak <ubizjak at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |wrong-code
Target Milestone|--- |4.7.0
Summary|Wrong vectorization |[4.7 Regression] Wrong
| |vectorization
--- Comment #1 from Uros Bizjak <ubizjak at gmail dot com> 2011-08-23 08:02:41 UTC ---
A regression from 4.6., and a very nasty one.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug tree-optimization/50162] [4.7 Regression] Wrong vectorization
2011-08-23 8:03 [Bug tree-optimization/50162] New: Wrong vectorization ubizjak at gmail dot com
2011-08-23 8:14 ` [Bug tree-optimization/50162] [4.7 Regression] " ubizjak at gmail dot com
@ 2011-08-23 8:53 ` rguenth at gcc dot gnu.org
2011-08-23 8:55 ` rguenth at gcc dot gnu.org
` (8 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu.org @ 2011-08-23 8:53 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50162
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2011-08-23
Ever Confirmed|0 |1
--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-08-23 08:40:43 UTC ---
Confirmed.
The vectorizer inserts the load:
vect_var_.13_22 = MEM[(double[256] *)vect_pa.9_20];
vect_pa.9_23 = vect_pa.9_20 + 16;
vect_var_.14_24 = MEM[(double[256] *)vect_pa.9_23];
vect_pa.9_25 = vect_pa.9_23 + 16;
vect_var_.15_26 = MEM[(double[256] *)vect_pa.9_25];
vect_pa.9_27 = vect_pa.9_25 + 16;
vect_var_.16_28 = MEM[(double[256] *)vect_pa.9_27];
but nothing uses it so it gets DCEd quickly.
vect_var_.17_29 = __builtin_ia32_vec_pack_sfix (vect_var_.13_22,
vect_var_.14_24);
vect_var_.17_30 = __builtin_ia32_vec_pack_sfix (vect_var_.14_24,
vect_var_.15_26);
you can see _24 is used twice - I suppose instead _28 should appear here
somehow.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug tree-optimization/50162] [4.7 Regression] Wrong vectorization
2011-08-23 8:03 [Bug tree-optimization/50162] New: Wrong vectorization ubizjak at gmail dot com
2011-08-23 8:14 ` [Bug tree-optimization/50162] [4.7 Regression] " ubizjak at gmail dot com
2011-08-23 8:53 ` rguenth at gcc dot gnu.org
@ 2011-08-23 8:55 ` rguenth at gcc dot gnu.org
2011-08-23 8:58 ` [Bug tree-optimization/50162] [4.5/4.6/4.7 " rguenth at gcc dot gnu.org
` (7 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu.org @ 2011-08-23 8:55 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50162
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
CC| |irar at gcc dot gnu.org
AssignedTo|unassigned at gcc dot |rguenth at gcc dot gnu.org
|gnu.org |
--- Comment #3 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-08-23 08:52:26 UTC ---
Fix:
Index: gcc/tree-vect-stmts.c
===================================================================
--- gcc/tree-vect-stmts.c (revision 177983)
+++ gcc/tree-vect-stmts.c (working copy)
@@ -1697,7 +1697,7 @@ vectorizable_call (gimple stmt, gimple_s
}
else
{
- vec_oprnd1 = gimple_call_arg (new_stmt, 2*i);
+ vec_oprnd1 = gimple_call_arg (new_stmt, 2*i + 1);
vec_oprnd0
= vect_get_vec_def_for_stmt_copy (dt[i], vec_oprnd1);
vec_oprnd1
Ira, does that make sense? I suppose we replace foo (a, b, c) with
foo_vec_pack (a1, a2, b1, b2, c1, c2), etc. And we want the second
argument from each pair from the last stmt? (I wonder if all this even
works for nargs != 1).
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug tree-optimization/50162] [4.5/4.6/4.7 Regression] Wrong vectorization
2011-08-23 8:03 [Bug tree-optimization/50162] New: Wrong vectorization ubizjak at gmail dot com
` (2 preceding siblings ...)
2011-08-23 8:55 ` rguenth at gcc dot gnu.org
@ 2011-08-23 8:58 ` rguenth at gcc dot gnu.org
2011-08-23 9:16 ` rguenth at gcc dot gnu.org
` (6 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu.org @ 2011-08-23 8:58 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50162
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Summary|[4.7 Regression] Wrong |[4.5/4.6/4.7 Regression]
|vectorization |Wrong vectorization
Known to fail| |4.5.3, 4.6.1, 4.7.0
--- Comment #4 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-08-23 08:54:52 UTC ---
Btw, same code is on the 4.6 branch - I wonder why the bug doesn't happen
there? It does. And on the 4.5 branch.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug tree-optimization/50162] [4.5/4.6/4.7 Regression] Wrong vectorization
2011-08-23 8:03 [Bug tree-optimization/50162] New: Wrong vectorization ubizjak at gmail dot com
` (3 preceding siblings ...)
2011-08-23 8:58 ` [Bug tree-optimization/50162] [4.5/4.6/4.7 " rguenth at gcc dot gnu.org
@ 2011-08-23 9:16 ` rguenth at gcc dot gnu.org
2011-08-23 10:22 ` [Bug tree-optimization/50162] [4.5/4.6 " rguenth at gcc dot gnu.org
` (5 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu.org @ 2011-08-23 9:16 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50162
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Known to work| |4.4.6
--- Comment #5 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-08-23 08:57:37 UTC ---
4.4 works though. Which has
for (i = 0; i < nargs; i++)
{
op = gimple_call_arg (stmt, i);
if (j == 0)
{
vec_oprnd0
= vect_get_vec_def_for_operand (op, stmt, NULL);
vec_oprnd1
= vect_get_vec_def_for_stmt_copy (dt[nargs], vec_oprnd0);
}
else
{
vec_oprnd0
= vect_get_vec_def_for_stmt_copy (dt[nargs], vec_oprnd1);
vec_oprnd1
= vect_get_vec_def_for_stmt_copy (dt[nargs], vec_oprnd0);
}
instead. Which surely doesn't work for nargs != 1 (?)
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug tree-optimization/50162] [4.5/4.6 Regression] Wrong vectorization
2011-08-23 8:03 [Bug tree-optimization/50162] New: Wrong vectorization ubizjak at gmail dot com
` (4 preceding siblings ...)
2011-08-23 9:16 ` rguenth at gcc dot gnu.org
@ 2011-08-23 10:22 ` rguenth at gcc dot gnu.org
2011-08-23 10:38 ` [Bug tree-optimization/50162] [4.5/4.6/4.7 " rguenth at gcc dot gnu.org
` (4 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu.org @ 2011-08-23 10:22 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50162
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Known to work| |4.7.0
Target Milestone|4.7.0 |4.5.4
Summary|[4.5/4.6/4.7 Regression] |[4.5/4.6 Regression] Wrong
|Wrong vectorization |vectorization
Known to fail|4.7.0 |
--- Comment #7 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-08-23 10:21:16 UTC ---
Fixed on trunk sofar.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug tree-optimization/50162] [4.5/4.6/4.7 Regression] Wrong vectorization
2011-08-23 8:03 [Bug tree-optimization/50162] New: Wrong vectorization ubizjak at gmail dot com
` (5 preceding siblings ...)
2011-08-23 10:22 ` [Bug tree-optimization/50162] [4.5/4.6 " rguenth at gcc dot gnu.org
@ 2011-08-23 10:38 ` rguenth at gcc dot gnu.org
2011-09-08 9:24 ` [Bug tree-optimization/50162] [4.5/4.6 " rguenth at gcc dot gnu.org
` (3 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu.org @ 2011-08-23 10:38 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50162
--- Comment #6 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-08-23 10:20:31 UTC ---
Author: rguenth
Date: Tue Aug 23 10:20:26 2011
New Revision: 177984
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=177984
Log:
2011-08-23 Richard Guenther <rguenther@suse.de>
PR tree-optimization/50162
* tree-vect-stmts.c (vectorizable_call): Fix argument lookup.
Modified:
trunk/gcc/ChangeLog
trunk/gcc/tree-vect-stmts.c
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug tree-optimization/50162] [4.5/4.6 Regression] Wrong vectorization
2011-08-23 8:03 [Bug tree-optimization/50162] New: Wrong vectorization ubizjak at gmail dot com
` (6 preceding siblings ...)
2011-08-23 10:38 ` [Bug tree-optimization/50162] [4.5/4.6/4.7 " rguenth at gcc dot gnu.org
@ 2011-09-08 9:24 ` rguenth at gcc dot gnu.org
2011-09-08 10:02 ` [Bug tree-optimization/50162] [4.5 " rguenth at gcc dot gnu.org
` (2 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu.org @ 2011-09-08 9:24 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50162
--- Comment #8 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-09-08 09:23:12 UTC ---
Author: rguenth
Date: Thu Sep 8 09:23:08 2011
New Revision: 178684
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=178684
Log:
2011-09-08 Richard Guenther <rguenther@suse.de>
Backport from mainline
2011-08-23 Richard Guenther <rguenther@suse.de>
PR tree-optimization/50162
* tree-vect-stmts.c (vectorizable_call): Fix argument lookup.
Modified:
branches/gcc-4_6-branch/gcc/ChangeLog
branches/gcc-4_6-branch/gcc/tree-vect-stmts.c
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug tree-optimization/50162] [4.5 Regression] Wrong vectorization
2011-08-23 8:03 [Bug tree-optimization/50162] New: Wrong vectorization ubizjak at gmail dot com
` (7 preceding siblings ...)
2011-09-08 9:24 ` [Bug tree-optimization/50162] [4.5/4.6 " rguenth at gcc dot gnu.org
@ 2011-09-08 10:02 ` rguenth at gcc dot gnu.org
2012-01-03 13:19 ` rguenth at gcc dot gnu.org
2012-01-03 13:21 ` rguenth at gcc dot gnu.org
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu.org @ 2011-09-08 10:02 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50162
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Known to work| |4.6.2
Summary|[4.5/4.6 Regression] Wrong |[4.5 Regression] Wrong
|vectorization |vectorization
--- Comment #9 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-09-08 09:23:49 UTC ---
And 4.6.2.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug tree-optimization/50162] [4.5 Regression] Wrong vectorization
2011-08-23 8:03 [Bug tree-optimization/50162] New: Wrong vectorization ubizjak at gmail dot com
` (8 preceding siblings ...)
2011-09-08 10:02 ` [Bug tree-optimization/50162] [4.5 " rguenth at gcc dot gnu.org
@ 2012-01-03 13:19 ` rguenth at gcc dot gnu.org
2012-01-03 13:21 ` rguenth at gcc dot gnu.org
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu.org @ 2012-01-03 13:19 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50162
--- Comment #10 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-01-03 13:19:35 UTC ---
Author: rguenth
Date: Tue Jan 3 13:19:28 2012
New Revision: 182843
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=182843
Log:
2012-01-03 Richard Guenther <rguenther@suse.de>
Backport from mainline
2011-08-23 Richard Guenther <rguenther@suse.de>
PR tree-optimization/50162
* tree-vect-stmts.c (vectorizable_call): Fix argument lookup.
Modified:
branches/gcc-4_5-branch/gcc/ChangeLog
branches/gcc-4_5-branch/gcc/tree-vect-stmts.c
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug tree-optimization/50162] [4.5 Regression] Wrong vectorization
2011-08-23 8:03 [Bug tree-optimization/50162] New: Wrong vectorization ubizjak at gmail dot com
` (9 preceding siblings ...)
2012-01-03 13:19 ` rguenth at gcc dot gnu.org
@ 2012-01-03 13:21 ` rguenth at gcc dot gnu.org
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu.org @ 2012-01-03 13:21 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50162
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution| |FIXED
--- Comment #11 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-01-03 13:19:56 UTC ---
Fixed.
^ permalink raw reply [flat|nested] 12+ messages in thread
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