slp-vectorizer miscompile #161140
Description
llvm commit: ab5bba5
Reproduce with:
opt -passes=slp-vectorizer bbi-110973_2.ll -S -o - -slp-threshold=-100
which results in
define i1 @foo(i1 %v) {
entry:
%0 = insertelement <2 x i1> poison, i1 %v, i32 0
%1 = shufflevector <2 x i1> %0, <2 x i1> poison, <2 x i32> zeroinitializer
%2 = mul <2 x i1> <i1 false, i1 true>, %1
%3 = extractelement <2 x i1> %2, i32 0
%4 = extractelement <2 x i1> %2, i32 1
%sub = sub i1 %3, %4
ret i1 %sub
}
If you e.g. calculate the result for input value %v == 1 you see that the results before/after slp-vectorizer are different.
See also
alive2