[PATCH] D19935: [BasicAA] Compare GEP indices based on value

[Ahmed Bougacha via llvm-commits]

ab added a comment.

Good catch; scary bug! The test is somewhat brittle though.  What do you think of boiling it down to its essence; something like:

  ; PR27418 - Treat GEP indices with the same value but different types the same
  ; CHECK-LABEL: test_different_index_types
  ; CHECK: MustAlias: i16* %tmp1, i16* %tmp2
  define void @test_different_index_types([2 x i16]* %arr) {
    %tmp1 = getelementptr [2 x i16], [2 x i16]* %arr, i16 0, i32 1
    %tmp2 = getelementptr [2 x i16], [2 x i16]* %arr, i16 0, i16 1
    ret void
  }

in struct-geps.ll ?  Looks like that actually used to return NoAlias (because of the assumption that C1 && C2 implies C1 != C2 later on).


http://reviews.llvm.org/D19935