[llvm] [BDCE] Handle multi-use `and`/`or` on demanded bits (PR #79688)

[Nikita Popov via llvm-commits]

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@@ -9,8 +9,7 @@ declare <2 x i32> @llvm.fshr.v2i32(<2 x i32>, <2 x i32>, <2 x i32>)
 ; First fshr operand is dead.
 define i32 @pr39771_fshr_multi_use_instr(i32 %a) {
 ; CHECK-LABEL: @pr39771_fshr_multi_use_instr(
-; CHECK-NEXT:    [[X:%.*]] = or i32 [[A:%.*]], 0
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nikic wrote:

Can you change the `or` operand to  `1` (or something else that doesn't optimize away) instead? Dropping it is not really the point of this tests.

https://github.com/llvm/llvm-project/pull/79688