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| author | Richard Biener <rguenther@suse.de> | 2022-02-15 12:27:14 +0100 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2022-02-15 13:22:15 +0100 |
| commit | d03a67dc69251dc86c0772a432380a6e9bcb8617 (patch) | |
| tree | 751d42d3e61a78d5aa8d25fc1d77a05cc9c78ab3 /gcc/gimple-loop-jam.cc | |
| parent | 3939c1b11279dc950d2f160eb940dd791f7b40f1 (diff) | |
| download | gcc-d03a67dc69251dc86c0772a432380a6e9bcb8617.zip gcc-d03a67dc69251dc86c0772a432380a6e9bcb8617.tar.gz gcc-d03a67dc69251dc86c0772a432380a6e9bcb8617.tar.bz2 | |
tree-optimization/104543 - fix unroll-and-jam precondition
We have to make sure that outer loop exits come after the inner
loop since we otherwise will put it into the fused loop body.
2022-02-15 Richard Biener <rguenther@suse.de>
PR tree-optimization/104543
* gimple-loop-jam.cc (unroll_jam_possible_p): Check outer loop exits
come after the inner loop.
* gcc.dg/torture/pr104543.c: New testcase.
Diffstat (limited to 'gcc/gimple-loop-jam.cc')
| -rw-r--r-- | gcc/gimple-loop-jam.cc | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/gcc/gimple-loop-jam.cc b/gcc/gimple-loop-jam.cc index d9a7772..e33dd90 100644 --- a/gcc/gimple-loop-jam.cc +++ b/gcc/gimple-loop-jam.cc @@ -198,7 +198,8 @@ unroll_jam_possible_p (class loop *outer, class loop *loop) if (!empty_block_p (loop->latch)) return false; - if (!single_exit (loop)) + edge exit; + if (!(exit = single_exit (loop))) return false; /* We need a perfect nest. Quick check for adjacent inner loops. */ @@ -259,7 +260,12 @@ unroll_jam_possible_p (class loop *outer, class loop *loop) n = get_loop_body_with_size (outer, bbs, n_basic_blocks_for_fn (cfun)); for (i = 0; i < n; i++) - if (bbs[i]->loop_father == outer && bb_prevents_fusion_p (bbs[i])) + if (bbs[i]->loop_father == outer + && (bb_prevents_fusion_p (bbs[i]) + /* Outer loop exits must come after the inner loop, otherwise + we'll put the outer loop exit into the fused inner loop. */ + || (loop_exits_from_bb_p (outer, bbs[i]) + && !dominated_by_p (CDI_DOMINATORS, bbs[i], exit->src)))) break; free (bbs); if (i != n) |