[InstructionSimplify] The result of icmp should be false.

[dianqk]

I tried this IR:

define i1 @src(i32 %X, i32 %Y, i32 %Z) {
  %A = lshr i32 %X, %Y
  %B = or i32 %X, %Z
  %C = icmp ult i32 %B, %A
  ret i1 %C
}

InstructionSimplify should infer that %C is false.
Alive2: https://alive2.llvm.org/ce/z/HvK2Ps

[topperc]

This looks overly reduced. alive2 also says that it can be optimized to ret i1 true or ret i1 undef.

[dianqk]

This looks overly reduced. alive2 also says that it can be optimized to ret i1 true or ret i1 undef.

Thanks for the reminder, I've updated it.

[dianqk]

We expect #69471 to address such issues.