TypePromotion produces invalid IR (take 2)

[nikic]

; RUN: opt -S -type-promotion < %s
target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
target triple = "aarch64-unknown-linux-gnu"

define i1 @test(i8 %arg) {
  %arg.ext = zext i8 %arg to i64
  %trunc = trunc i64 %arg.ext to i3
  %switch.tableidx = xor i3 %trunc, 1
  %switch.maskindex = zext i3 %trunc to i8
  %switch.lobit = icmp ne i8 %switch.maskindex, 0
  ret i1 %switch.lobit
}

Results in a verifier error:

Both operands to a binary operator are not of the same type!
  %switch.tableidx = xor i64 %1, i32 1
in function test

The produced IR looks as follows:

define i1 @test(i8 %arg) {
  %arg.ext = zext i8 %arg to i64
  %1 = and i64 %arg.ext, 7
  %switch.tableidx = xor i64 %1, i32 1
  %2 = trunc i64 %1 to i32
  %switch.lobit = icmp ne i32 %2, 0
  ret i1 %switch.lobit
}

The symptoms here are similar to #58843, but the fix for that one did not fix this case.

[llvmbot]

@llvm/issue-subscribers-backend-aarch64

[nikic]

cc @bcl5980, as you worked on the previous fix.

[bcl5980]

Candidate patch: https://reviews.llvm.org/D140869

[nikic]

/cherry-pick a0b470c