[llvm] [ARM] Custom lower abdu and abds (PR #182696)

[Eli Friedman via llvm-commits]

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@@ -597,8 +597,12 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM_,
   if (!Subtarget->hasV8_1MMainlineOps())
     setOperationAction(ISD::UCMP, MVT::i32, Custom);
 
-  if (!Subtarget->isThumb1Only())
+  if (!Subtarget->isThumb1Only()) {
     setOperationAction(ISD::ABS, MVT::i32, Custom);
+    setOperationAction(ISD::ABDS, MVT::i32, Custom);
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efriedma-quic wrote:

It looks like you went to some effort to make LowerABD() work for Thumb1 ABDS; why did you end up disabling it?

https://github.com/llvm/llvm-project/pull/182696