[clang] [Clang][AArch64] set default mtune (PR #179136)

[Ricardo Jesus via cfe-commits]

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@@ -244,9 +286,10 @@ void aarch64::getAArch64TargetFeatures(const Driver &D,
     success = getAArch64MicroArchFeaturesFromMtune(D, A->getValue(), Args);
   else if (success && (A = Args.getLastArg(options::OPT_mcpu_EQ)))
     success = getAArch64MicroArchFeaturesFromMcpu(D, A->getValue(), Args);
-  else if (success && isCPUDeterminedByTriple(Triple))
-    success = getAArch64MicroArchFeaturesFromMcpu(
-        D, getAArch64TargetCPUByTriple(Triple), Args);
+  else if (success) {
+    if (auto TuneCPUOpt = getAArch64TargetTuneCPUByTriple(Triple))
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rj-jesus wrote:

Maybe call this `TuneCPU` for consistency with aarch64::getAArch64TargetTuneCPU and Clang::AddAArch64TargetArgs?

https://github.com/llvm/llvm-project/pull/179136