[llvm] [AArch64][ISel] Add lowering for i8 clmul intrinsics (PR #177323)

[David Green via llvm-commits]

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@@ -1323,6 +1323,11 @@ def fminnum_nnan : PatFrag<(ops node:$Rn, node:$Rm),
   return N->getFlags().hasNoNaNs();
   }]>;
 
+def pmul_or_clmul : PatFrags<(ops node:$Rn, node:$Rm),
+                             [(int_aarch64_neon_pmul node:$Rn, node:$Rm),
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davemgreen wrote:

I think if we wanted to do that at a higher level, we could replace the intrinsic in clang (and add AutoUpgrade code for turning old aarch64.neon.pmul into llvm.clmul). The aarch64.neon.pmul intrinsics could then be removed.

https://github.com/llvm/llvm-project/pull/177323