https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68776
Bug ID: 68776
Summary: [6 regression]
gcc.dg/vect/vect-widen-mult-const-[su]16.c failures
since r226675
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: wschmidt at gcc dot gnu.org
CC: rguenth at gcc dot gnu.org
Target Milestone: ---
Host: powerpc*-*-linux*
Target: powerpc*-*-linux*
Build: powerpc*-*-linux*
Created attachment 36946
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36946&action=edit
Vectorization dump for r226674
Since r226675, we have been seeing these failures:
FAIL: gcc.dg/vect/vect-widen-mult-const-s16.c -flto -ffat-lto-objects
scan-tree-dump-times vect "pattern recognized" 2
FAIL: gcc.dg/vect/vect-widen-mult-const-s16.c scan-tree-dump-times vect
"pattern recognized" 2
FAIL: gcc.dg/vect/vect-widen-mult-const-u16.c -flto -ffat-lto-objects
scan-tree-dump-times vect "pattern recognized" 2
FAIL: gcc.dg/vect/vect-widen-mult-const-u16.c scan-tree-dump-times vect
"pattern recognized" 2
Comparing the vect-details dumps from r226674 to r226675, I see these as
the reason:
63a64,66
> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:16:3:
> note: vect_recog_mult_pattern: detected:
> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:16:3:
> note: patt_47 = _6 << 2;
> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:16:3:
> note: pattern recognized: patt_47 = _6 << 2;
70a74,76
> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:16:3:
> note: vect_recog_mult_pattern: detected:
> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:16:3:
> note: patt_40 = _6 << 1;
> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:16:3:
> note: pattern recognized: patt_40 = _6 << 1;
747a754,756
> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:31:3:
> note: vect_recog_mult_pattern: detected:
> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:31:3:
> note: patt_47 = _6 << 2;
> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:31:3:
> note: pattern recognized: patt_47 = _6 << 2;
754a764,766
> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:31:3:
> note: vect_recog_mult_pattern: detected:
> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:31:3:
> note: patt_40 = _6 << 1;
> /home/wschmidt/gcc/gcc-mainline-base/gcc/testsuite/gcc.dg/vect/vect-widen-mult-const-s16.c:31:3:
> note: pattern recognized: patt_40 = _6 << 1;
These do not show up for x86_64, so the DejaGnu patterns:
/* { dg-final { scan-tree-dump-times "pattern recognized" 2 "vect" { target
vect_widen_mult_hi_to_si_pattern } } } */
have different results for these different targets, even though both support
vect_widen_mult_hi_to_si_pattern.
Detailed vectorization dumps from powerpc64le-unknown-linux-gnu before and
after this revision are attached.
