https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127092
--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The trunk branch has been updated by Andrea Pinski <[email protected]>: https://gcc.gnu.org/g:0acb69bf9bb0db14b7e230fb5370257c530fb6e8 commit r17-3869-g0acb69bf9bb0db14b7e230fb5370257c530fb6e8 Author: Andrea Pinski <[email protected]> Date: Mon Aug 31 21:22:49 2026 -0700 range-op: Fix some divisions [PR127092] This was an oversight of not knowing there are a few different integer divisions and how they will round. When `a < b` and for non-negative a and b, `a/b` will be 0 iff for truncate (TRUNC_DIV_EXPR), exact (EXACT_DIV_EXPR) and floor division (FLOOR_DIV_EXPR). Ceiling division (CEIL_DIV_EXPR) will be 1 for positive a and zero when a is 0. Rounding division (ROUND_DIV_EXPR) it is based on the how far a is from b. We can skip the ceiling division case since it is not used that much. And rounding division case is too hard to figure out here so that is skipped also. Bootstrapped and tested on x86_64-linux-gnu. PR tree-optimization/127092 gcc/ChangeLog: * range-op.cc (operator_div::op1_op2_relation_effect): Only handle TRUNC_DIV_EXPR, EXACT_DIV_EXPR and FLOOR_DIV_EXPR for the `a < b` case. gcc/testsuite/ChangeLog: * gfortran.dg/pr127092-1.f90: New test. Signed-off-by: Andrea Pinski <[email protected]>
