commit de6d9e0b3d5c08896cbf047b299fc7f8d1e42be7 Author: Andrew MacLeod Date: Mon Aug 22 15:40:48 2022 -0400 Return the correct relation With an input condition of op1 > op2, and evaluating the unsigned expression: LHS = op1 - op2 range-ops was returning LHS < op1 , which is incorrect as op2 coould be zero. This patch adjusts it to return LHS <= op1. PR tree-optimization/106687 gcc/ * range-op.cc (operator_minus::lhs_op1_relation): Return VREL_LE for the VREL_GT case as well. gcc/testsuite/ * g++.dg/pr106687.C: New. diff --git a/gcc/range-op.cc b/gcc/range-op.cc index dfdd971c90a..806edf1012e 100644 --- a/gcc/range-op.cc +++ b/gcc/range-op.cc @@ -1378,7 +1378,6 @@ operator_minus::lhs_op1_relation (const irange &, const irange &op1, switch (rel) { case VREL_GT: - return VREL_LT; case VREL_GE: return VREL_LE; default: diff --git a/gcc/testsuite/g++.dg/pr106687.C b/gcc/testsuite/g++.dg/pr106687.C new file mode 100644 index 00000000000..75ac81c216c --- /dev/null +++ b/gcc/testsuite/g++.dg/pr106687.C @@ -0,0 +1,22 @@ +// { dg-do run } +// { dg-options "-O2" } + +bool var_0 = (bool)0; +unsigned int var_7 = 42; +char var_215; + +int main() { + unsigned b = var_0; + unsigned p2 = var_7; + unsigned *tp; + if (b < p2) + tp = &p2; + else + tp = &b; + unsigned tt = *tp; + unsigned t = tt ^ (var_7 - var_0); + var_215 = t ? t : 42; + if (var_215 != 42) + __builtin_abort(); + return 0; +}