If I give instcombine the following IR:
define i1 @f([1 x i8]* %a, [1 x i8]* %b) {
%c = getelementptr [1 x i8]* %a, i32 0, i32 0
%d = getelementptr [1 x i8]* %b, i32 0, i32 0
%cmp = icmp ult i8* %c, %d
ret i1 %cmp
}
It optimizes it into:
define i1 @f([1 x i8]* %a, [1 x i8]* %b) {
%cmp = icmp slt [1 x i8]* %a, %b
ret i1 %cmp
}
Is this a bug, or are there some semantics of icmp or getelementptr I'm missing that mean it's OK to change this from an unsigned comparison to a signed comparison?