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| author | Aldy Hernandez <aldyh@redhat.com> | 2020-10-26 17:50:37 +0100 |
|---|---|---|
| committer | Aldy Hernandez <aldyh@redhat.com> | 2020-10-26 19:05:53 +0100 |
| commit | 2118438f49f0c193abe3fa3def350a8129045746 (patch) | |
| tree | 9a14a7334ad2760d8c7ccbdb4de9220544e1c068 /gcc/tree-ssa-alias.c | |
| parent | f20a6c57f0f26d9c60d6d6182f1e2181f727c834 (diff) | |
| download | gcc-2118438f49f0c193abe3fa3def350a8129045746.zip gcc-2118438f49f0c193abe3fa3def350a8129045746.tar.gz gcc-2118438f49f0c193abe3fa3def350a8129045746.tar.bz2 | |
Handle signed 1-bit ranges in irange::invert.
The problem here is we are trying to add 1 to a -1 in a signed 1-bit
field and coming up with UNDEFINED because of the overflow.
Signed 1-bits are annoying because you can't really add or subtract
one, because the one is unrepresentable. For invert() we have a
special subtract_one() function that handles 1-bit signed fields.
This patch implements the analogous add_one() function so that invert
works.
gcc/ChangeLog:
PR tree-optimization/97555
* range-op.cc (range_tests): Test 1-bit signed invert.
* value-range.cc (subtract_one): Adjust comment.
(add_one): New.
(irange::invert): Call add_one.
gcc/testsuite/ChangeLog:
* gcc.dg/pr97555.c: New test.
Diffstat (limited to 'gcc/tree-ssa-alias.c')
0 files changed, 0 insertions, 0 deletions