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