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author | Richard Biener <rguenther@suse.de> | 2024-04-24 08:42:40 +0200 |
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committer | Richard Biener <rguenther@suse.de> | 2024-05-06 14:10:09 +0200 |
commit | 715a1df9082b40cf810283632218258ac9c86773 (patch) | |
tree | 3892e0077207c20dc794dd0c2b4ed89b60fc993a /gcc | |
parent | 4c3011ec4825bf06c9d268361a53f8239bf9564a (diff) | |
download | gcc-715a1df9082b40cf810283632218258ac9c86773.zip gcc-715a1df9082b40cf810283632218258ac9c86773.tar.gz gcc-715a1df9082b40cf810283632218258ac9c86773.tar.bz2 |
tree-optimization/114787 - more careful loop update with CFG cleanup
When CFG cleanup removes a backedge we have to be more careful with
loop update. In particular we need to clear niter info and estimates
and if we remove the last backedge of a loop we have to also mark
it for removal to prevent a following basic block merging to associate
loop info with an unrelated header.
PR tree-optimization/114787
* tree-cfg.cc (remove_edge_and_dominated_blocks): When
removing a loop backedge clear niter info and when removing
the last backedge of a loop mark that loop for removal.
* gcc.dg/torture/pr114787.c: New testcase.
(cherry picked from commit cc48418cfc2e555d837ae9138cbfac23acb3cdf9)
Diffstat (limited to 'gcc')
-rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr114787.c | 27 | ||||
-rw-r--r-- | gcc/tree-cfg.cc | 26 |
2 files changed, 50 insertions, 3 deletions
diff --git a/gcc/testsuite/gcc.dg/torture/pr114787.c b/gcc/testsuite/gcc.dg/torture/pr114787.c new file mode 100644 index 0000000..1c7294b --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr114787.c @@ -0,0 +1,27 @@ +/* { dg-do run } */ + +int a, b, c, d, e = -1, f, g, h, j, k, n, o, p; +int main() { + int i, l = 2, m; + for (b = 0; b < 1; b++) + l = 0; + for (; a >= 0; a--) + for (m = 3; m; m--) { + k = g; + i = 0; + for (; i < 1; i++) + for (; f < 1; f++) + h = g; + n = 2 & ((e ^ d) | 1) * j; + o = ~(e & n); + q: + if (c <= e) + return 0; + e = o; + } + p = l; + l = 0; + if (p) + goto q; + return 0; +} diff --git a/gcc/tree-cfg.cc b/gcc/tree-cfg.cc index a9fcc7f..98c6a0d 100644 --- a/gcc/tree-cfg.cc +++ b/gcc/tree-cfg.cc @@ -8872,10 +8872,30 @@ remove_edge_and_dominated_blocks (edge e) /* If we are removing a path inside a non-root loop that may change loop ownership of blocks or remove loops. Mark loops for fixup. */ + class loop *src_loop = e->src->loop_father; if (current_loops - && loop_outer (e->src->loop_father) != NULL - && e->src->loop_father == e->dest->loop_father) - loops_state_set (LOOPS_NEED_FIXUP); + && loop_outer (src_loop) != NULL + && src_loop == e->dest->loop_father) + { + loops_state_set (LOOPS_NEED_FIXUP); + /* If we are removing a backedge clear the number of iterations + and estimates. */ + class loop *dest_loop = e->dest->loop_father; + if (e->dest == src_loop->header + || (e->dest == dest_loop->header + && flow_loop_nested_p (dest_loop, src_loop))) + { + free_numbers_of_iterations_estimates (dest_loop); + /* If we removed the last backedge mark the loop for removal. */ + FOR_EACH_EDGE (f, ei, dest_loop->header->preds) + if (f != e + && (f->src->loop_father == dest_loop + || flow_loop_nested_p (dest_loop, f->src->loop_father))) + break; + if (!f) + mark_loop_for_removal (dest_loop); + } + } if (!dom_info_available_p (CDI_DOMINATORS)) { |