[PATCH] D45107: [InstCombine] [NFC] Add tests for getting rid of select of bittest (PR36950 / PR17564)

[Sanjay Patel via Phabricator via llvm-commits]

spatel added inline comments.


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Comment at: test/Transforms/InstCombine/select-of-bittest.ll:447-450
+define i32 @n9(i32) {
+; CHECK-LABEL: @n9(
+; CHECK-NEXT:    ret i32 1
+;
----------------
This is testing that some other folds work as expected, so it doesn't really belong here IMO.


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Comment at: test/Transforms/InstCombine/select-of-bittest.ll:467
+  %3 = icmp eq i32 %2, 0
+  %4 = lshr i32 %0, 32 ; shifting by 32 leaves no bits
+  %5 = and i32 %4, 1
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Similar to @n9, I'd remove this test because the pattern shouldn't survive as-is before we get to the select. 

The comment isn't correct - shifting by the bit-width produces a poison value.


Repository:
  rL LLVM

https://reviews.llvm.org/D45107