https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104279
--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:a1544878966020d1f7a640b35d1f7a5f0e055624 commit r12-6931-ga1544878966020d1f7a640b35d1f7a5f0e055624 Author: Jakub Jelinek <ja...@redhat.com> Date: Sat Jan 29 17:54:43 2022 +0100 match.pd: Fix up 1 / X for unsigned X optimization [PR104280] On Fri, Jan 28, 2022 at 11:38:23AM -0700, Jeff Law wrote: > Thanks. Given the original submission and most of the review work was done > prior to stage3 closing, I went ahead and installed this on the trunk. Unfortunately this breaks quite a lot of things. The main problem is that GIMPLE allows EQ_EXPR etc. only with BOOLEAN_TYPE or with TYPE_PRECISION == 1 integral type (or vector boolean). Violating this causes verification failures in tree-cfg.cc in some cases, in other cases wrong-code issues because before it is verified we e.g. transform 1U / x into x == 1U and later into x (because we assume that == type must be one of the above cases and when it is the same type as the type of the first operand, for boolean-ish cases it should be equivalent). Fixed by changing that (eq @1 { build_one_cst (type); }) into (convert (eq:boolean_type_node @1 { build_one_cst (type); })) Note, I'm not 100% sure if :boolean_type_node is required in that case, I see some spots in match.pd that look exactly like this, while there is e.g. (convert (le ...)) that supposedly does the right thing too. The signed integer 1/X case doesn't need changes changes, for (cond (le ...) ...) le gets correctly boolean_type_node and cond should use type. I've also reformatted it, some lines were too long, match.pd uses indentation by 1 column instead of 2 etc. 2022-01-29 Jakub Jelinek <ja...@redhat.com> Andrew Pinski <apin...@marvell.com> PR tree-optimization/104279 PR tree-optimization/104280 PR tree-optimization/104281 * match.pd (1 / X -> X == 1 for unsigned X): Build eq with boolean_type_node and convert to type. Formatting fixes. * gcc.dg/torture/pr104279.c: New test. * gcc.dg/torture/pr104280.c: New test. * gcc.dg/torture/pr104281.c: New test.
