[llvm] [DAGCombiner] Fold subtraction if above threshold to `umin` (PR #134235)

[Luke Lau via llvm-commits]

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@@ -1479,3 +1479,215 @@ entry:
   %cmp = icmp ne i32 %popcnt, 1
   ret i1 %cmp
 }
+
+define i8 @sub_if_uge_i8(i8 %x, i8 %y) {
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lukel97 wrote:

The ULT just seems to be the canonical form from instcombine

https://github.com/llvm/llvm-project/pull/134235