[llvm] [Attributor] Propagate alignment through ptrmask (PR #150158)

[Shilei Tian via llvm-commits]

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@@ -5188,6 +5188,81 @@ struct AADereferenceableCallSiteReturned final
 // ------------------------ Align Argument Attribute ------------------------
 
 namespace {
+
+Align getKnownAlignForIntrinsic(Attributor &A, AAAlign &QueryingAA,
+                                const IntrinsicInst *II) {
+  switch (II->getIntrinsicID()) {
+  case Intrinsic::ptrmask: {
+    const auto *ConstVals = A.getAAFor<AAPotentialConstantValues>(
+        QueryingAA, IRPosition::value(*(II->getOperand(1))), DepClassTy::NONE);
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shiltian wrote:

I think what @Shoreshen is doing here is to teach `AAAlign` to provide alignment information for this specific intrinsic.

However, I'm not sure what the `AlignAA` is doing here.

https://github.com/llvm/llvm-project/pull/150158