Allow subclassing ExternalAA

This allows testing AMDGPU alias analysis like any
other alias analysis pass. This fixes the existing
test pointlessly running opt -O3 when it really
just wants to run the one analysis.

Before there was no way to test this using -aa-eval
with opt, since the default constructed pass
is run. The wrapper subclass allows the
default constructor to pass the necessary callback.

llvm-svn: 346353

llvm/include/llvm/Analysis/AliasAnalysis.h

@@ -1074,6 +1074,29 @@ public:
   void getAnalysisUsage(AnalysisUsage &AU) const override;
 };
 
+/// A wrapper pass for external alias analyses. This just squirrels away the
+/// callback used to run any analyses and register their results.
+struct ExternalAAWrapperPass : ImmutablePass {
+  using CallbackT = std::function<void(Pass &, Function &, AAResults &)>;
+
+  CallbackT CB;
+
+  static char ID;
+
+  ExternalAAWrapperPass() : ImmutablePass(ID) {
+    initializeExternalAAWrapperPassPass(*PassRegistry::getPassRegistry());
+  }
+
+  explicit ExternalAAWrapperPass(CallbackT CB)
+      : ImmutablePass(ID), CB(std::move(CB)) {
+    initializeExternalAAWrapperPassPass(*PassRegistry::getPassRegistry());
+  }
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.setPreservesAll();
+  }
+};
+
 FunctionPass *createAAResultsWrapperPass();
 
 /// A wrapper pass around a callback which can be used to populate the

llvm/lib/Analysis/AliasAnalysis.cpp

@@ -640,28 +640,6 @@ AnalysisKey AAManager::Key;
 
 namespace {
 
-/// A wrapper pass for external alias analyses. This just squirrels away the
-/// callback used to run any analyses and register their results.
-struct ExternalAAWrapperPass : ImmutablePass {
-  using CallbackT = std::function<void(Pass &, Function &, AAResults &)>;
-
-  CallbackT CB;
-
-  static char ID;
-
-  ExternalAAWrapperPass() : ImmutablePass(ID) {
-    initializeExternalAAWrapperPassPass(*PassRegistry::getPassRegistry());
-  }
-
-  explicit ExternalAAWrapperPass(CallbackT CB)
-      : ImmutablePass(ID), CB(std::move(CB)) {
-    initializeExternalAAWrapperPassPass(*PassRegistry::getPassRegistry());
-  }
-
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.setPreservesAll();
-  }
-};
 
 } // end anonymous namespace
 

llvm/lib/Target/AMDGPU/AMDGPU.h

@@ -198,6 +198,8 @@ extern char &AMDGPUUnifyDivergentExitNodesID;
 
 ImmutablePass *createAMDGPUAAWrapperPass();
 void initializeAMDGPUAAWrapperPassPass(PassRegistry&);
+ImmutablePass *createAMDGPUExternalAAWrapperPass();
+void initializeAMDGPUExternalAAWrapperPass(PassRegistry&);
 
 void initializeAMDGPUArgumentUsageInfoPass(PassRegistry &);
 

llvm/lib/Target/AMDGPU/AMDGPUAliasAnalysis.cpp

@@ -34,14 +34,22 @@ using namespace llvm;
 
 // Register this pass...
 char AMDGPUAAWrapperPass::ID = 0;
+char AMDGPUExternalAAWrapper::ID = 0;
 
 INITIALIZE_PASS(AMDGPUAAWrapperPass, "amdgpu-aa",
                 "AMDGPU Address space based Alias Analysis", false, true)
 
+INITIALIZE_PASS(AMDGPUExternalAAWrapper, "amdgpu-aa-wrapper",
+                "AMDGPU Address space based Alias Analysis Wrapper", false, true)
+
 ImmutablePass *llvm::createAMDGPUAAWrapperPass() {
   return new AMDGPUAAWrapperPass();
 }
 
+ImmutablePass *llvm::createAMDGPUExternalAAWrapperPass() {
+  return new AMDGPUExternalAAWrapper();
+}
+
 void AMDGPUAAWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.setPreservesAll();
 }

llvm/lib/Target/AMDGPU/AMDGPUAliasAnalysis.h

@@ -96,6 +96,19 @@ public:
   void getAnalysisUsage(AnalysisUsage &AU) const override;
 };
 
+// Wrapper around ExternalAAWrapperPass so that the default constructor gets the
+// callback.
+class AMDGPUExternalAAWrapper : public ExternalAAWrapperPass {
+public:
+  static char ID;
+
+  AMDGPUExternalAAWrapper() : ExternalAAWrapperPass(
+    [](Pass &P, Function &, AAResults &AAR) {
+      if (auto *WrapperPass = P.getAnalysisIfAvailable<AMDGPUAAWrapperPass>())
+        AAR.addAAResult(WrapperPass->getResult());
+    }) {}
+};
+
 } // end namespace llvm
 
 #endif // LLVM_LIB_TARGET_AMDGPU_AMDGPUALIASANALYSIS_H

llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp

@@ -192,6 +192,7 @@ extern "C" void LLVMInitializeAMDGPUTarget() {
   initializeSIFormMemoryClausesPass(*PR);
   initializeAMDGPUUnifyDivergentExitNodesPass(*PR);
   initializeAMDGPUAAWrapperPassPass(*PR);
+  initializeAMDGPUExternalAAWrapperPass(*PR);
   initializeAMDGPUUseNativeCallsPass(*PR);
   initializeAMDGPUSimplifyLibCallsPass(*PR);
   initializeAMDGPUInlinerPass(*PR);
@@ -340,13 +341,6 @@ StringRef AMDGPUTargetMachine::getFeatureString(const Function &F) const {
     FSAttr.getValueAsString();
 }
 
-static ImmutablePass *createAMDGPUExternalAAWrapperPass() {
-  return createExternalAAWrapperPass([](Pass &P, Function &, AAResults &AAR) {
-      if (auto *WrapperPass = P.getAnalysisIfAvailable<AMDGPUAAWrapperPass>())
-        AAR.addAAResult(WrapperPass->getResult());
-      });
-}
-
 /// Predicate for Internalize pass.
 static bool mustPreserveGV(const GlobalValue &GV) {
   if (const Function *F = dyn_cast<Function>(&GV))

llvm/test/CodeGen/AMDGPU/amdgpu-alias-analysis.ll

@@ -1,5 +1,5 @@
-; RUN: opt -mtriple=amdgcn-- -O3 -aa-eval -print-all-alias-modref-info -disable-output < %s 2>&1 | FileCheck %s
-; RUN: opt -mtriple=r600-- -O3 -aa-eval -print-all-alias-modref-info -disable-output < %s 2>&1 | FileCheck %s
+; RUN: opt -mtriple=amdgcn-- -aa-eval -amdgpu-aa -amdgpu-aa-wrapper -disable-basicaa  -print-all-alias-modref-info -disable-output < %s 2>&1 | FileCheck %s
+; RUN: opt -mtriple=r600-- -aa-eval -amdgpu-aa -amdgpu-aa-wrapper -disable-basicaa  -print-all-alias-modref-info -disable-output < %s 2>&1 | FileCheck %s
 
 ; CHECK: NoAlias:      i8 addrspace(1)* %p1, i8 addrspace(5)* %p