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* [Bug tree-optimization/56918] New: incorrect auto-vectorization of array initialization
@ 2013-04-11 11:04 kretz at kde dot org
2013-04-11 11:42 ` [Bug tree-optimization/56918] [4.8 Regression] " rguenth at gcc dot gnu.org
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: kretz at kde dot org @ 2013-04-11 11:04 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56918
Bug #: 56918
Summary: incorrect auto-vectorization of array initialization
Classification: Unclassified
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: kretz@kde.org
Compile the following testcase with "gcc -m32 -O2 -ftree-vectorize -msse2"
int main() {
double data[4];
for (int i = 0; i < 2 * 2; ++i) {
data[i] = ((i + 2) % 3) + 1;
}
if (data[0] != 3.) {
return 1;
}
return 0;
}
The first for-loop calculates the values 6, 7, 8, 9 instead of the expected 3,
1, 2, 3.
^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug tree-optimization/56918] [4.8 Regression] incorrect auto-vectorization of array initialization 2013-04-11 11:04 [Bug tree-optimization/56918] New: incorrect auto-vectorization of array initialization kretz at kde dot org @ 2013-04-11 11:42 ` rguenth at gcc dot gnu.org 2013-04-11 11:59 ` rguenth at gcc dot gnu.org ` (3 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: rguenth at gcc dot gnu.org @ 2013-04-11 11:42 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56918 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2013-04-11 Known to work| |4.9.0 Target Milestone|--- |4.8.1 Summary|incorrect |[4.8 Regression] incorrect |auto-vectorization of array |auto-vectorization of array |initialization |initialization Ever Confirmed|0 |1 Known to fail| |4.8.0 --- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> 2013-04-11 11:42:49 UTC --- extern void abort (void); double data[4]; int main() { int i; for (i = 0; i < 2 * 2; ++i) data[i] = ((i + 2) % 3) + 1; if (data[0] != 3) abort (); return 0; } Seems to work on trunk. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/56918] [4.8 Regression] incorrect auto-vectorization of array initialization 2013-04-11 11:04 [Bug tree-optimization/56918] New: incorrect auto-vectorization of array initialization kretz at kde dot org 2013-04-11 11:42 ` [Bug tree-optimization/56918] [4.8 Regression] " rguenth at gcc dot gnu.org @ 2013-04-11 11:59 ` rguenth at gcc dot gnu.org 2013-04-11 14:43 ` jakub at gcc dot gnu.org ` (2 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: rguenth at gcc dot gnu.org @ 2013-04-11 11:59 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56918 --- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> 2013-04-11 11:59:05 UTC --- The vectorizer does nothing wrong. The bug goes away with -fdisable-tree-vrp2 which would expose - stmp_var_.3_2 = 0 + 1; - stmp_var_.3_19 = stmp_var_.3_2 + 1; - stmp_var_.3_20 = stmp_var_.3_19 + 1; - vect_cst_.4_21 = {0, stmp_var_.3_2, stmp_var_.3_19, stmp_var_.3_20}; + stmp_var_.3_2 = 1; + stmp_var_.3_19 = 2; + stmp_var_.3_20 = 3; + vect_cst_.4_21 = { 0, 1, 2, 3 }; (ick, unfolded 0 + 1) so we expand vect_patt.11_29 = { 2, 3, 4, 5 } >> 31; vect_patt.12_30 = { -1, -1, -1, -1 } - vect_patt.11_29; vect_patt.13_32 = vect_patt.12_30 * { 3, 3, 3, 3 }; vect_patt.15_33 = { 2, 3, 4, 5 } - vect_patt.13_32; vect_var_.16_35 = vect_patt.15_33 + { 1, 1, 1, 1 }; vect_var_.18_36 = [vec_unpack_float_lo_expr] vect_var_.16_35; vect_var_.18_37 = [vec_unpack_float_hi_expr] vect_var_.16_35; MEM[(double[1024] *)&data] = vect_var_.18_36; MEM[(double[1024] *)&data + 16B] = vect_var_.18_37; _10 = data[0]; if (_10 != 3.0e+0) where I bet that unfolded constant expressions are somehow mis-handled. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/56918] [4.8 Regression] incorrect auto-vectorization of array initialization 2013-04-11 11:04 [Bug tree-optimization/56918] New: incorrect auto-vectorization of array initialization kretz at kde dot org 2013-04-11 11:42 ` [Bug tree-optimization/56918] [4.8 Regression] " rguenth at gcc dot gnu.org 2013-04-11 11:59 ` rguenth at gcc dot gnu.org @ 2013-04-11 14:43 ` jakub at gcc dot gnu.org 2013-04-11 15:20 ` jakub at gcc dot gnu.org 2013-04-12 9:13 ` jakub at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: jakub at gcc dot gnu.org @ 2013-04-11 14:43 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56918 Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |ASSIGNED AssignedTo|unassigned at gcc dot |jakub at gcc dot gnu.org |gnu.org | --- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-04-11 14:43:30 UTC --- Created attachment 29858 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29858 gcc49-pr56918.patch Untested fix. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/56918] [4.8 Regression] incorrect auto-vectorization of array initialization 2013-04-11 11:04 [Bug tree-optimization/56918] New: incorrect auto-vectorization of array initialization kretz at kde dot org ` (2 preceding siblings ...) 2013-04-11 14:43 ` jakub at gcc dot gnu.org @ 2013-04-11 15:20 ` jakub at gcc dot gnu.org 2013-04-12 9:13 ` jakub at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: jakub at gcc dot gnu.org @ 2013-04-11 15:20 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56918 --- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-04-11 15:20:11 UTC --- *** Bug 56920 has been marked as a duplicate of this bug. *** ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/56918] [4.8 Regression] incorrect auto-vectorization of array initialization 2013-04-11 11:04 [Bug tree-optimization/56918] New: incorrect auto-vectorization of array initialization kretz at kde dot org ` (3 preceding siblings ...) 2013-04-11 15:20 ` jakub at gcc dot gnu.org @ 2013-04-12 9:13 ` jakub at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: jakub at gcc dot gnu.org @ 2013-04-12 9:13 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56918 Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|ASSIGNED |RESOLVED Resolution| |FIXED --- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-04-12 09:13:24 UTC --- Author: jakub Date: Fri Apr 12 08:18:59 2013 New Revision: 197846 URL: http://gcc.gnu.org/viewcvs?rev=197846&root=gcc&view=rev Log: PR tree-optimization/56918 PR tree-optimization/56920 * fold-const.c (int_const_binop_1): Use op1.mul_with_sign (op2, ...) instead of op1 - op2. Pass 2 * TYPE_PRECISION (type) as second argument to rshift method. For 2 * HOST_BITS_PER_WIDE_INT precision use wide_mul_with_sign method. * gcc.dg/vect/pr56918.c: New test. * gcc.dg/vect/pr56920.c: New test. Added: trunk/gcc/testsuite/gcc.dg/vect/pr56918.c trunk/gcc/testsuite/gcc.dg/vect/pr56920.c Modified: trunk/gcc/ChangeLog trunk/gcc/fold-const.c trunk/gcc/testsuite/ChangeLog Author: jakub Date: Fri Apr 12 08:38:29 2013 New Revision: 197847 URL: http://gcc.gnu.org/viewcvs?rev=197847&root=gcc&view=rev Log: PR tree-optimization/56918 PR tree-optimization/56920 * fold-const.c (int_const_binop_1): Use op1.mul_with_sign (op2, ...) instead of op1 - op2. Pass 2 * TYPE_PRECISION (type) as second argument to rshift method. * gcc.dg/vect/pr56918.c: New test. * gcc.dg/vect/pr56920.c: New test. Added: branches/gcc-4_8-branch/gcc/testsuite/gcc.dg/vect/pr56918.c branches/gcc-4_8-branch/gcc/testsuite/gcc.dg/vect/pr56920.c Modified: branches/gcc-4_8-branch/gcc/ChangeLog branches/gcc-4_8-branch/gcc/fold-const.c branches/gcc-4_8-branch/gcc/testsuite/ChangeLog ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2013-04-12 9:13 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2013-04-11 11:04 [Bug tree-optimization/56918] New: incorrect auto-vectorization of array initialization kretz at kde dot org 2013-04-11 11:42 ` [Bug tree-optimization/56918] [4.8 Regression] " rguenth at gcc dot gnu.org 2013-04-11 11:59 ` rguenth at gcc dot gnu.org 2013-04-11 14:43 ` jakub at gcc dot gnu.org 2013-04-11 15:20 ` jakub at gcc dot gnu.org 2013-04-12 9:13 ` jakub at gcc dot gnu.org
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