[RPOFunctionAttrs] Use LazyCallGraph instead of CallGraph

There are a few more uses of CallGraph that should be replaced with LazyCallGraph

Also delete legacy version of RPOFunctionAttrs since it is deprecated and LazyCallGraph is not available under the legacy pass manager.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D143358

Author: saeubank

llvm/include/llvm/InitializePasses.h

@@ -345,7 +345,6 @@ void initializeRemoveRedundantDebugValuesPass(PassRegistry&);
 void initializeRenameIndependentSubregsPass(PassRegistry&);
 void initializeReplaceWithVeclibLegacyPass(PassRegistry &);
 void initializeResetMachineFunctionPass(PassRegistry&);
-void initializeReversePostOrderFunctionAttrsLegacyPassPass(PassRegistry&);
 void initializeRewriteStatepointsForGCLegacyPassPass(PassRegistry &);
 void initializeRewriteSymbolsLegacyPassPass(PassRegistry&);
 void initializeSCCPLegacyPassPass(PassRegistry&);

llvm/include/llvm/LinkAllPasses.h

@@ -168,7 +168,6 @@ namespace {
       (void) llvm::createAttributorLegacyPass();
       (void) llvm::createAttributorCGSCCLegacyPass();
       (void) llvm::createPostOrderFunctionAttrsLegacyPass();
-      (void) llvm::createReversePostOrderFunctionAttrsPass();
       (void) llvm::createMergeICmpsLegacyPass();
       (void) llvm::createExpandLargeDivRemPass();
       (void) llvm::createExpandMemCmpPass();

llvm/include/llvm/Transforms/IPO.h

@@ -116,13 +116,6 @@ Pass *createLoopExtractorPass();
 ///
 Pass *createSingleLoopExtractorPass();
 
-//===----------------------------------------------------------------------===//
-/// createReversePostOrderFunctionAttrsPass - This pass walks SCCs of the call
-/// graph in RPO to deduce and propagate function attributes. Currently it
-/// only handles synthesizing norecurse attributes.
-///
-Pass *createReversePostOrderFunctionAttrsPass();
-
 //===----------------------------------------------------------------------===//
 /// createBarrierNoopPass - This pass is purely a module pass barrier in a pass
 /// manager.

llvm/lib/Transforms/IPO/FunctionAttrs.cpp

@@ -1871,42 +1871,6 @@ bool PostOrderFunctionAttrsLegacyPass::runOnSCC(CallGraphSCC &SCC) {
   return runImpl(SCC, LegacyAARGetter(*this));
 }
 
-namespace {
-
-struct ReversePostOrderFunctionAttrsLegacyPass : public ModulePass {
-  // Pass identification, replacement for typeid
-  static char ID;
-
-  ReversePostOrderFunctionAttrsLegacyPass() : ModulePass(ID) {
-    initializeReversePostOrderFunctionAttrsLegacyPassPass(
-        *PassRegistry::getPassRegistry());
-  }
-
-  bool runOnModule(Module &M) override;
-
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.setPreservesCFG();
-    AU.addRequired<CallGraphWrapperPass>();
-    AU.addPreserved<CallGraphWrapperPass>();
-  }
-};
-
-} // end anonymous namespace
-
-char ReversePostOrderFunctionAttrsLegacyPass::ID = 0;
-
-INITIALIZE_PASS_BEGIN(ReversePostOrderFunctionAttrsLegacyPass,
-                      "rpo-function-attrs", "Deduce function attributes in RPO",
-                      false, false)
-INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
-INITIALIZE_PASS_END(ReversePostOrderFunctionAttrsLegacyPass,
-                    "rpo-function-attrs", "Deduce function attributes in RPO",
-                    false, false)
-
-Pass *llvm::createReversePostOrderFunctionAttrsPass() {
-  return new ReversePostOrderFunctionAttrsLegacyPass();
-}
-
 static bool addNoRecurseAttrsTopDown(Function &F) {
   // We check the preconditions for the function prior to calling this to avoid
   // the cost of building up a reversible post-order list. We assert them here
@@ -1939,49 +1903,41 @@ static bool addNoRecurseAttrsTopDown(Function &F) {
   return true;
 }
 
-static bool deduceFunctionAttributeInRPO(Module &M, CallGraph &CG) {
+static bool deduceFunctionAttributeInRPO(Module &M, LazyCallGraph &CG) {
   // We only have a post-order SCC traversal (because SCCs are inherently
   // discovered in post-order), so we accumulate them in a vector and then walk
   // it in reverse. This is simpler than using the RPO iterator infrastructure
   // because we need to combine SCC detection and the PO walk of the call
   // graph. We can also cheat egregiously because we're primarily interested in
   // synthesizing norecurse and so we can only save the singular SCCs as SCCs
   // with multiple functions in them will clearly be recursive.
-  SmallVector<Function *, 16> Worklist;
-  for (scc_iterator<CallGraph *> I = scc_begin(&CG); !I.isAtEnd(); ++I) {
-    if (I->size() != 1)
-      continue;
 
-    Function *F = I->front()->getFunction();
-    if (F && !F->isDeclaration() && !F->doesNotRecurse() &&
-        F->hasInternalLinkage())
-      Worklist.push_back(F);
+  SmallVector<Function *, 16> Worklist;
+  CG.buildRefSCCs();
+  for (LazyCallGraph::RefSCC &RC : CG.postorder_ref_sccs()) {
+    for (LazyCallGraph::SCC &SCC : RC) {
+      if (SCC.size() != 1)
+        continue;
+      Function &F = SCC.begin()->getFunction();
+      if (!F.isDeclaration() && !F.doesNotRecurse() && F.hasInternalLinkage())
+        Worklist.push_back(&F);
+    }
   }
-
   bool Changed = false;
   for (auto *F : llvm::reverse(Worklist))
     Changed |= addNoRecurseAttrsTopDown(*F);
 
   return Changed;
 }
 
-bool ReversePostOrderFunctionAttrsLegacyPass::runOnModule(Module &M) {
-  if (skipModule(M))
-    return false;
-
-  auto &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();
-
-  return deduceFunctionAttributeInRPO(M, CG);
-}
-
 PreservedAnalyses
 ReversePostOrderFunctionAttrsPass::run(Module &M, ModuleAnalysisManager &AM) {
-  auto &CG = AM.getResult<CallGraphAnalysis>(M);
+  auto &CG = AM.getResult<LazyCallGraphAnalysis>(M);
 
   if (!deduceFunctionAttributeInRPO(M, CG))
     return PreservedAnalyses::all();
 
   PreservedAnalyses PA;
-  PA.preserve<CallGraphAnalysis>();
+  PA.preserve<LazyCallGraphAnalysis>();
   return PA;
 }

llvm/lib/Transforms/IPO/IPO.cpp

@@ -40,7 +40,6 @@ void llvm::initializeIPO(PassRegistry &Registry) {
   initializeAttributorLegacyPassPass(Registry);
   initializeAttributorCGSCCLegacyPassPass(Registry);
   initializePostOrderFunctionAttrsLegacyPassPass(Registry);
-  initializeReversePostOrderFunctionAttrsLegacyPassPass(Registry);
   initializeIPSCCPLegacyPassPass(Registry);
   initializeBarrierNoopPass(Registry);
   initializeEliminateAvailableExternallyLegacyPassPass(Registry);

llvm/lib/Transforms/IPO/PassManagerBuilder.cpp

@@ -357,8 +357,6 @@ void PassManagerBuilder::populateModulePassManager(
     // and saves running remaining passes on the eliminated functions.
     MPM.add(createEliminateAvailableExternallyPass());
 
-  MPM.add(createReversePostOrderFunctionAttrsPass());
-
   // The inliner performs some kind of dead code elimination as it goes,
   // but there are cases that are not really caught by it. We might
   // at some point consider teaching the inliner about them, but it

llvm/test/Other/new-pm-lto-defaults.ll

@@ -62,7 +62,6 @@
 ; CHECK-O-NEXT: Running analysis: TypeBasedAA
 ; CHECK-O-NEXT: Running analysis: OuterAnalysisManagerProxy
 ; CHECK-O-NEXT: Running pass: ReversePostOrderFunctionAttrsPass
-; CHECK-O-NEXT: Running analysis: CallGraphAnalysis
 ; CHECK-O-NEXT: Running pass: GlobalSplitPass
 ; CHECK-O-NEXT: Running pass: WholeProgramDevirtPass
 ; CHECK-O1-NEXT: Running pass: LowerTypeTestsPass
@@ -92,6 +91,7 @@
 ; CHECK-O23SZ-NEXT: Running pass: PostOrderFunctionAttrsPass on (foo)
 ; CHECK-O23SZ-NEXT: Running pass: RequireAnalysisPass<{{.*}}GlobalsAA
 ; CHECK-O23SZ-NEXT: Running analysis: GlobalsAA on [module]
+; CHECK-O23SZ-NEXT: Running analysis: CallGraphAnalysis on [module]
 ; CHECK-O23SZ-NEXT: Running pass: InvalidateAnalysisPass<{{.*}}AAManager
 ; CHECK-O23SZ-NEXT: Invalidating analysis: AAManager on foo
 ; CHECK-O23SZ-NEXT: Running pass: OpenMPOptCGSCCPass on (foo)