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

[Shilei Tian via llvm-commits]

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@@ -5187,6 +5187,33 @@ struct AADereferenceableCallSiteReturned final
 // ------------------------ Align Argument Attribute ------------------------
 
 namespace {
+
+Align getAssumedAlignForIntrinsic(Attributor &A, AAAlign &QueryingAA,
+                                  const IntrinsicInst &II) {
+  Align Alignment;
+  switch (II.getIntrinsicID()) {
+  case Intrinsic::ptrmask: {
+    const auto *ConstVals = A.getAAFor<AAPotentialConstantValues>(
+        QueryingAA, IRPosition::value(*II.getOperand(1)), DepClassTy::REQUIRED);
+    const auto *AlignAA =
+        A.getAAFor<AAAlign>(QueryingAA, IRPosition::value(*(II.getOperand(0))),
+                            DepClassTy::REQUIRED);
+    if (ConstVals && ConstVals->isValidState()) {
+      unsigned ShiftValue =
+          std::min(ConstVals->getAssumedMinTrailingZeros(), 63U);
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shiltian wrote:

Do we want to use `Value::MaxAlignmentExponent` here as well?

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