[llvm] [PowerPC] Add custom lowering for ssubo (#111748) (PR #115875)

[via llvm-commits]

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@@ -200,6 +200,11 @@ PPCTargetLowering::PPCTargetLowering(const PPCTargetMachine &TM,
 
   setOperationAction(ISD::UADDO, isPPC64 ? MVT::i64 : MVT::i32, Custom);
 
+  // On P10, the default lowering generates better code using the
+  // setbc instruction.
+  if (!Subtarget.hasP10Vector() && isPPC64)
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RolandF77 wrote:

Why only for 64-bit?

https://github.com/llvm/llvm-project/pull/115875