1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py 2; RUN: opt < %s -passes=instsimplify 3 4; The mul can be proved to always overflow (turning a negative value 5; into a positive one) and thus results in undefined behaviour. At 6; the same time we were deducing from the nsw flag that that mul could 7; be assumed to have a negative value (since if not it has an undefined 8; value, which can be taken to be negative). We were reporting the mul 9; as being both positive and negative, firing an assertion! 10define i1 @test1(i32 %a) { 11entry: 12 %0 = or i32 %a, 1 13 %1 = shl i32 %0, 31 14 %2 = mul nsw i32 %1, 4 15 %3 = and i32 %2, -4 16 %4 = icmp ne i32 %3, 0 17 ret i1 %4 18} 19