[llvm] [RISCV][ISel] Fold trunc (lshr (add (zext X), (zext Y)), 1) -> vaaddu X, Y (PR #76550)

[Luke Lau via llvm-commits]

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@@ -1385,9 +1390,6 @@ RISCVTargetLowering::RISCVTargetLowering(const TargetMachine &TM,
   if (Subtarget.hasStdExtZbb())
     setTargetDAGCombine({ISD::UMAX, ISD::UMIN, ISD::SMAX, ISD::SMIN});
 
-  if (Subtarget.hasStdExtZbs() && Subtarget.is64Bit())
-    setTargetDAGCombine(ISD::TRUNCATE);
-
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lukel97 wrote:

We can restore this too

https://github.com/llvm/llvm-project/pull/76550