[llvm] [RISCV] Use Zacas for AtomicRMWInst::Nand i32 and XLen. (PR #80119)

[Yingwei Zheng via llvm-commits]

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@@ -19517,6 +19517,11 @@ RISCVTargetLowering::shouldExpandAtomicRMWInIR(AtomicRMWInst *AI) const {
   unsigned Size = AI->getType()->getPrimitiveSizeInBits();
   if (Size == 8 || Size == 16)
     return AtomicExpansionKind::MaskedIntrinsic;
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dtcxzyw wrote:

It would be good to use amocas for i8/i16 if both zacas and zabha are supported.


https://github.com/llvm/llvm-project/pull/80119