[PATCH] D140666: [InstCombine] combine intersection for inequality icmps

[Yingchi Long via Phabricator via llvm-commits]

inclyc added a comment.

> I don't think BMask_Mixed and BMask_NotMixed will happen at the same time.

`LLVM.Transforms/InstCombine::sign-test-and-or.ll` has given us an example.

  define i1 @test9(i32 %a) {
  ; CHECK-LABEL: @test9(
  ; CHECK-NEXT:    [[TMP1:%.*]] = and i32 [[A:%.*]], -1073741824
  ; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i32 [[TMP1]], 1073741824
  ; CHECK-NEXT:    ret i1 [[TMP2]]
  ;
    %1 = and i32 %a, 1073741824
    %2 = icmp ne i32 %1, 0
    %3 = icmp sgt i32 %a, -1
    %or.cond = and i1 %2, %3
    ret i1 %or.cond
  }

I'm not sure about this, but the debugger showed me `Mask = BMask_Mixed | BMask_NotMixed`. Can you reproduce this on your machine?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D140666/new/

https://reviews.llvm.org/D140666