https://gcc.gnu.org/g:0e91910c0708a60b3ac521a4ea74e44301109f4a
commit r16-4179-g0e91910c0708a60b3ac521a4ea74e44301109f4a Author: Richard Biener <[email protected]> Date: Wed Oct 1 14:16:50 2025 +0200 tree-optimization/122079 - PRE antic_compute doesn't converge The following fixes another case of us pruning from the value set based on the expression set after expression removal when the maximum expression set is involved. PR tree-optimization/122079 * tree-ssa-pre.cc (prune_clobbered_mems): Do not prune values when the maximum expression set is involved. * gcc.dg/torture/pr122079-1.c: New testcase. Diff: --- gcc/testsuite/gcc.dg/torture/pr122079-1.c | 27 +++++++++++++++++++++++++++ gcc/tree-ssa-pre.cc | 8 ++++++-- 2 files changed, 33 insertions(+), 2 deletions(-) diff --git a/gcc/testsuite/gcc.dg/torture/pr122079-1.c b/gcc/testsuite/gcc.dg/torture/pr122079-1.c new file mode 100644 index 000000000000..0af01a581a17 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr122079-1.c @@ -0,0 +1,27 @@ +/* { dg-do compile } */ +/* { dg-additional-options "-fcode-hoisting" } */ + +int a, b, c; +void e(int *f) { + int d = 0; + if (f) + goto g; + goto h; +i: + d = 1 + f[0]; +j: + if (c) + goto h; +k: + if (b) + goto i; + if (a) + goto j; +g: + if (d + f[0]) + goto k; +h: + int l[] = {f[0]}; + if (a) + e(l); +} diff --git a/gcc/tree-ssa-pre.cc b/gcc/tree-ssa-pre.cc index 64ffaca21aba..d08caab952a1 100644 --- a/gcc/tree-ssa-pre.cc +++ b/gcc/tree-ssa-pre.cc @@ -2049,8 +2049,12 @@ prune_clobbered_mems (bitmap_set_t set, basic_block block, bool clean_traps) the bitmap_find_leader way to see if there's still an expression for it. For some ratio of to be removed values and number of values/expressions in the set this might be faster than rebuilding - the value-set. */ - if (any_removed) + the value-set. + Note when there's a MAX solution on one edge (clean_traps) do not + prune values as we need to consider the resulting expression set MAX + as well. This avoids a later growing ANTIC_IN value-set during + iteration, when the explicitly represented expression set grows. */ + if (any_removed && !clean_traps) { bitmap_clear (&set->values); FOR_EACH_EXPR_ID_IN_SET (set, i, bi)
