[llvm] [RISCV][GISel] Lower G_ABDS and G_ABDU (PR #155888)

[Craig Topper via llvm-commits]

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@@ -1337,6 +1337,9 @@ bool RISCVLegalizerInfo::legalizeCustom(
     return false;
   case TargetOpcode::G_ABS:
     return Helper.lowerAbsToMaxNeg(MI);
+  case TargetOpcode::G_ABDS:
+  case TargetOpcode::G_ABDU:
+    return Helper.lowerAbsDiffToMinMax(MI);
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topperc wrote:

Can we make this decision in the legalizer using `LI.isLegal` to check if min/max is legal?

https://github.com/llvm/llvm-project/pull/155888