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| author | Jakub Jelinek <jakub@redhat.com> | 2021-01-05 10:57:52 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2021-01-05 10:59:00 +0100 |
| commit | 4615cde5d7ef281d4b554df411f82ad707f0a54d (patch) | |
| tree | 69005f7b86e4e76b7fed0153ad53bb708f0966a6 /gcc/tree-ssa-reassoc.c | |
| parent | 6b69738c1e30ec31cb11dce1d9209e7a5b92301b (diff) | |
| download | gcc-4615cde5d7ef281d4b554df411f82ad707f0a54d.zip gcc-4615cde5d7ef281d4b554df411f82ad707f0a54d.tar.gz gcc-4615cde5d7ef281d4b554df411f82ad707f0a54d.tar.bz2 | |
simplify-rtx: Optimize (x - 1) * y + y [PR98334]
We don't try to optimize for signed x, y (int) (x - 1U) * y + y
into x * y, we can't do that with signed x * y, because the former
is well defined for INT_MIN and -1, while the latter is not.
We could perhaps optimize it during isel or some very late optimization
where we'd turn magically flag_wrapv, but we don't do that yet.
This patch optimizes it in simplify-rtx.c, such that we can optimize
it during combine.
2021-01-05 Jakub Jelinek <jakub@redhat.com>
PR rtl-optimization/98334
* simplify-rtx.c (simplify_context::simplify_binary_operation_1):
Optimize (X - 1) * Y + Y to X * Y or (X + 1) * Y - Y to X * Y.
* gcc.target/i386/pr98334.c: New test.
Diffstat (limited to 'gcc/tree-ssa-reassoc.c')
0 files changed, 0 insertions, 0 deletions