Add ExternalAAWrapperPass to createLegacyPMAAResults.

Our out-of-tree custom aliasing solution for the HPC# Burst compiler
here at Unity makes use of the `ExternalAAwrapperPass` infrastructure to
insert our custom aliasing resolution into the core of LLVM. This is
great for all cases except for function inlining, where because
`createLegacyPMAAResults` does not make use of `ExternalAAWrapperPass`,
when we have a definite no-alias result within a function it won't be
propagated to the calling function during inlining.

This commit just rectifies this oversight by adding the missing
dependency.

Differential Revision: https://reviews.llvm.org/D71348

1 files changed, 5 insertions, 0 deletions

diff --git a/llvm/lib/Analysis/AliasAnalysis.cpp b/llvm/lib/Analysis/AliasAnalysis.cpp
index c56c8a74af8..1c7678a602d 100644
--- a/llvm/lib/Analysis/AliasAnalysis.cpp
+++ b/llvm/lib/Analysis/AliasAnalysis.cpp
@@ -846,6 +846,7 @@ void AAResultsWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.addUsedIfAvailable<SCEVAAWrapperPass>();
   AU.addUsedIfAvailable<CFLAndersAAWrapperPass>();
   AU.addUsedIfAvailable<CFLSteensAAWrapperPass>();
+  AU.addUsedIfAvailable<ExternalAAWrapperPass>();
 }
 
 AAResults llvm::createLegacyPMAAResults(Pass &P, Function &F,
@@ -871,6 +872,9 @@ AAResults llvm::createLegacyPMAAResults(Pass &P, Function &F,
     AAR.addAAResult(WrapperPass->getResult());
   if (auto *WrapperPass = P.getAnalysisIfAvailable<CFLSteensAAWrapperPass>())
     AAR.addAAResult(WrapperPass->getResult());
+  if (auto *WrapperPass = P.getAnalysisIfAvailable<ExternalAAWrapperPass>())
+    if (WrapperPass->CB)
+      WrapperPass->CB(P, F, AAR);
 
   return AAR;
 }
@@ -914,4 +918,5 @@ void llvm::getAAResultsAnalysisUsage(AnalysisUsage &AU) {
   AU.addUsedIfAvailable<GlobalsAAWrapperPass>();
   AU.addUsedIfAvailable<CFLAndersAAWrapperPass>();
   AU.addUsedIfAvailable<CFLSteensAAWrapperPass>();
+  AU.addUsedIfAvailable<ExternalAAWrapperPass>();
 }