[llvm] Reapply "[CodeGen][AArch64] Avoid duplicate hints in register allocation (#219007)" (#224451) (PR #224742)

[Tomer Shafir via llvm-commits]

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@@ -1260,8 +1260,7 @@ bool AArch64RegisterInfo::getRegAllocationHints(
     return ConsiderOnlyHints;
 
   if (!ST.hasSME() || !ST.isStreaming())
-    return TargetRegisterInfo::getRegAllocationHints(VirtReg, Order, Hints, MF,
-                                                     VRM);
+    return ConsiderOnlyHints;
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tomershafir wrote:

I think it might be better to split the `AArch64RegisterInfo` change to a separate NFC patch, so this patch better isolates the main functional change and its test.

https://github.com/llvm/llvm-project/pull/224742