[flang-commits] [flang] [flang] AliasAnalysis: distinguish addr of arg vs. addr in arg (PR #87723)

[Joel E. Denny via flang-commits]

================
@@ -399,19 +404,30 @@ AliasAnalysis::Source AliasAnalysis::getSource(mlir::Value v) {
   if (!defOp && type == SourceKind::Unknown)
     // Check if the memory source is coming through a dummy argument.
     if (isDummyArgument(v)) {
-      type = SourceKind::Argument;
       ty = v.getType();
       if (fir::valueHasFirAttribute(v, fir::getTargetAttrName()))
         attributes.set(Attribute::Target);
-
       if (Source::isPointerReference(ty))
         attributes.set(Attribute::Pointer);
+      if (followBoxAddr && fir::isa_ref_type(ty))
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jdenny-ornl wrote:

After further thought, maybe there is a cleaner way to write this check:

- Declare a new `followBoxAddrLoad` variable local to `AliasAnalysis::getSource`, and set it to true right before the `return` in the `fir::LoadOp` case.
- For the dummy arg check above, replace `followBoxAddr && fir::isa_ref_type(ty)` with `followBoxAddrLoad`.
- For the `fir::AddrOfOp` check, replace `followBoxAddr && mlir::isa<fir::BaseBoxType>(fir::unwrapRefType(ty))` with `followBoxAddrLoad`.

I tried that, and check-flang still succeeded.  What do you think?

https://github.com/llvm/llvm-project/pull/87723