Hi! As mentioned in the PR, we ICE because maybe_fold_*_comparisons returns an expression with V4SImode type and we try to fold_convert it to V4BImode, which isn't allowed.
IMHO no matter whether we change maybe_fold_*_comparisons we should play safe on the reassoc side and punt if we can't convert like we punt for many other reasons. This fixes the testcase on ARM. Bootstrapped/regtested on {x86_64,i686,armv7hl,aarch64,powerpc64le}-linux, ok for trunk? Testcase not included, not exactly sure where and what directives it should have in gcc.target/arm/ testsuite. Christophe, do you think you could handle that incrementally? 2022-04-26 Jakub Jelinek <ja...@redhat.com> PR tree-optimization/105374 * tree-ssa-reassoc.cc (eliminate_redundant_comparison): Punt if !fold_convertible_p rather than assuming fold_convert must succeed. --- gcc/tree-ssa-reassoc.cc.jj 2022-04-14 13:46:59.690140053 +0200 +++ gcc/tree-ssa-reassoc.cc 2022-04-25 15:34:03.811473537 +0200 @@ -2254,7 +2254,11 @@ eliminate_redundant_comparison (enum tre BIT_AND_EXPR or BIT_IOR_EXPR was of a wider integer type, we need to convert. */ if (!useless_type_conversion_p (TREE_TYPE (curr->op), TREE_TYPE (t))) - t = fold_convert (TREE_TYPE (curr->op), t); + { + if (!fold_convertible_p (TREE_TYPE (curr->op), t)) + continue; + t = fold_convert (TREE_TYPE (curr->op), t); + } if (TREE_CODE (t) != INTEGER_CST && !operand_equal_p (t, curr->op, 0)) Jakub