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| author | Richard Biener <rguenther@suse.de> | 2021-07-22 12:26:16 +0200 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2021-07-27 10:46:22 +0200 |
| commit | 66030d68a7edfc9504a50469598e0707b8f787ce (patch) | |
| tree | a005e80a5eacf12378a75971b856ed6c0d9771a7 /gcc/tree-vrp.c | |
| parent | c8ce54c6e67295b70052d1b9f9a2f7ce9e2f8f0d (diff) | |
| download | gcc-66030d68a7edfc9504a50469598e0707b8f787ce.zip gcc-66030d68a7edfc9504a50469598e0707b8f787ce.tar.gz gcc-66030d68a7edfc9504a50469598e0707b8f787ce.tar.bz2 | |
tree-optimization/101573 - improve uninit warning at -O0
We can improve uninit warnings from the early pass by looking
at PHI arguments on fallthru edges that are uninitialized and
have uses that are before a possible loop exit. This catches
some cases earlier that we'd only warn in a more confusing
way after early inlining as seen by testcase adjustments.
It introduces
FAIL: gcc.dg/uninit-23.c (test for excess errors)
where we additionally warn
gcc.dg/uninit-23.c:21:13: warning: 't4' is used uninitialized [-Wuninitialized]
which I think is OK even if it's not obvious that the new
warning is an improvement when you look at the obvious source.
Somehow for all cases I never get the `'foo' was declared here`
notes, I didn't dig why that happens but it's odd.
2021-07-22 Richard Biener <rguenther@suse.de>
PR tree-optimization/101573
* tree-ssa-uninit.c (warn_uninit_phi_uses): New function
looking at uninitialized PHI arg defs in some constrained cases.
(warn_uninitialized_vars): Call it.
(execute_early_warn_uninitialized): Calculate dominators.
* gcc.dg/uninit-pr101573.c: New testcase.
* gcc.dg/uninit-15-O0.c: Adjust.
* gcc.dg/uninit-15.c: Likewise.
* gcc.dg/uninit-23.c: Likewise.
* c-c++-common/uninit-17.c: Likewise.
Diffstat (limited to 'gcc/tree-vrp.c')
0 files changed, 0 insertions, 0 deletions