Bug 115373 - [15 Regression] RISCV slp-cond-2-big-array.c slp-cond-2.c scan-tree-dump fails since r15-859-geaaa4b88038
Summary: [15 Regression] RISCV slp-cond-2-big-array.c slp-cond-2.c scan-tree-dump fail...
Status: RESOLVED FIXED
Alias: None
Product: gcc
Classification: Unclassified
Component: tree-optimization (show other bugs)
Version: 15.0
: P3 normal
Target Milestone: 15.0
Assignee: Not yet assigned to anyone
URL:
Keywords: testsuite-fail
Depends on:
Blocks: vectorizer 116578
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Reported: 2024-06-06 18:31 UTC by Patrick O'Neill
Modified: 2024-09-30 12:05 UTC (History)
2 users (show)

See Also:
Host:
Target: riscv, aarch64
Build:
Known to work:
Known to fail:
Last reconfirmed: 2024-08-16 00:00:00

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Description Patrick O'Neill 2024-06-06 18:31:07 UTC 
Commit range (2 possible commits):
r15-858-g65aa46ffc3b
r15-859-geaaa4b88038 < 99.9% sure it's this one since it updated the test expectations

Regressed:

FAIL: gcc.dg/vect/slp-cond-2-big-array.c -flto -ffat-lto-objects  scan-tree-dump-times vect "vectorizing stmts using SLP" 4
FAIL: gcc.dg/vect/slp-cond-2-big-array.c scan-tree-dump-times vect "vectorizing stmts using SLP" 4
FAIL: gcc.dg/vect/slp-cond-2.c -flto -ffat-lto-objects  scan-tree-dump-times vect "vectorizing stmts using SLP" 4
FAIL: gcc.dg/vect/slp-cond-2.c scan-tree-dump-times vect "vectorizing stmts using SLP" 4

Debug output:
gcc.dg/vect/slp-cond-2-big-array.c -flto -ffat-lto-objects : pattern found 3 times
FAIL: gcc.dg/vect/slp-cond-2-big-array.c -flto -ffat-lto-objects  scan-tree-dump-times vect "vectorizing stmts using SLP" 4
gcc.dg/vect/slp-cond-2-big-array.c: pattern found 3 times
FAIL: gcc.dg/vect/slp-cond-2-big-array.c scan-tree-dump-times vect "vectorizing stmts using SLP" 4
gcc.dg/vect/slp-cond-2.c -flto -ffat-lto-objects : pattern found 3 times
FAIL: gcc.dg/vect/slp-cond-2.c -flto -ffat-lto-objects  scan-tree-dump-times vect "vectorizing stmts using SLP" 4
gcc.dg/vect/slp-cond-2.c: pattern found 3 times
FAIL: gcc.dg/vect/slp-cond-2.c scan-tree-dump-times vect "vectorizing stmts using SLP" 4
Comment 1 Patrick O'Neill 2024-06-06 18:31:39 UTC 
Relevant postcommit issue: https://github.com/patrick-rivos/gcc-postcommit-ci/issues/999
Comment 2 Richard Biener 2024-06-07 06:04:46 UTC 
This also wasn't seen in precommit CI.  I can confirm it on trunk and the
issue is that we prefer load-lanes for f3 instead of SLP.

This issue will go away when we do load-lanes from SLP, so it's intermittent
(but I can't promise any timeline).  I wonder if the FAIL also occurs on
aarch64.  There's vect_load_lanes to eventually "fix" the FAIL by adjusting
the testcase expectation.
Comment 3 Richard Biener 2024-06-07 06:13:08 UTC 
Same on aarch64.
Comment 4 Thiago Jung Bauermann 2024-06-27 01:23:28 UTC 
We also see it on arm --with-mode=thumb.

FWIW this is being tracked in the Linaro CI at:

https://linaro.atlassian.net/browse/GNU-1222
Comment 5 Richard Biener 2024-09-30 12:05:47 UTC 
This seems to be fixed now for both risc-v and aarch64 (with or without SVE).