[llvm] [SelectionDAG] Expand [US]CMP using arithmetic on boolean values instead of selects (PR #98774)

[Nikita Popov via llvm-commits]

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@@ -0,0 +1,155 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc -mtriple=thumbv7-apple-darwin %s -o - | FileCheck %s
+
+define i8 @scmp_8_8(i8 %x, i8 %y) nounwind {
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nikic wrote:

```suggestion
define i8 @scmp_8_8(i8 signext %x, i8 signext %y) nounwind {
```
And zeroext for the ucmp case. ARM ABI zero/sign extends small integers.

https://github.com/llvm/llvm-project/pull/98774