[clang] [llvm] [mlir] [AArch64][SME] Improve codegen for aarch64.sme.cnts* when not in streaming mode (PR #154761)

[Benjamin Maxwell via cfe-commits]

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@@ -4918,6 +4919,31 @@ Value *CodeGenFunction::EmitAArch64SMEBuiltinExpr(unsigned BuiltinID,
   // Handle builtins which require their multi-vector operands to be swapped
   swapCommutativeSMEOperands(BuiltinID, Ops);
 
+  auto isCntsBuiltin = [&](int64_t &Mul) {
+    switch (BuiltinID) {
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MacDue wrote:

nit: This could just return the `mul`, and the use below could be `if (auto mul = isCntsBuiltin()))`

https://github.com/llvm/llvm-project/pull/154761