[flang-commits] [flang] [flang] Use alias analysis in lowering record assignments (PR #176483)

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@@ -1566,8 +1567,14 @@ void fir::factory::genRecordAssignment(fir::FirOpBuilder &builder,
       mlir::isa<fir::BaseBoxType>(fir::getBase(rhs).getType());
   auto recTy = mlir::dyn_cast<fir::RecordType>(baseTy);
   assert(recTy && "must be a record type");
+
+  // Use alias analysis to guard the fast path.
+  fir::AliasAnalysis aa;
+  bool disjoint = aa.alias(fir::getBase(lhs), fir::getBase(rhs)) ==
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jeanPerier wrote:

Oups, sorry, yes I meant `disjoint = isTemporaryLHS ...`, and this should not cause not new regressions, I assume this may come from the fact that extra parentheses are needed `disjoint = isTemporaryLHS || (aa.alias(fir::getBase(lhs), fir::getBase(rhs)) == mlir::AliasResult::NoAlias)`.

>  [...] and then use that to guard the guard itself (as in, say, recTy.isSequence()?).

Yes, I will review your new update, thanks

> or is the preference to have a single combined patch?

I prefer to do it either as a pre-patch or a combined patch like you did (a post patch would have opened the door to perf regressions and having to spent time analyzing them to validate they come from this patch/will be fixed).

https://github.com/llvm/llvm-project/pull/176483