[llvm] [ARM] Speedups for CombineBaseUpdate. (PR #129725)

[David Green via llvm-commits]

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@@ -16242,6 +16250,10 @@ static SDValue CombineBaseUpdate(SDNode *N,
   const unsigned AddrOpIdx = ((isIntrinsic || isStore) ? 2 : 1);
   BaseUpdateTarget Target = {N, isIntrinsic, isStore, AddrOpIdx};
 
+  // Limit the number of possible base-updates we look at to prevent degenerate
+  // cases.
+  unsigned MaxBaseUpdates = ArmMaxBaseUpdatesToCheck;
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davemgreen wrote:

Yeah I added this mostly as a place to put the comment. It could also help to not dereference the global multiple times, but that likely isn't a huge issue.

https://github.com/llvm/llvm-project/pull/129725