From cea1e4e79a76734bacbb76ab99ba267aca7e7499 Mon Sep 17 00:00:00 2001
From: Peter Collingbourne <peter@pcc.me.uk>
Date: Thu, 9 Feb 2017 23:11:52 +0000
Subject: [PATCH] De-duplicate some code for creating an AARGetter suitable for
 the legacy PM.

I'm about to use this in a couple more places.

Differential Revision: https://reviews.llvm.org/D29793

llvm-svn: 294648
---
 .../include/llvm/Analysis/BasicAliasAnalysis.h | 18 ++++++++++++++++++
 llvm/lib/Transforms/IPO/ArgumentPromotion.cpp  | 11 +----------
 llvm/lib/Transforms/IPO/FunctionAttrs.cpp      | 16 ++--------------
 llvm/lib/Transforms/IPO/Inliner.cpp            | 12 +-----------
 4 files changed, 22 insertions(+), 35 deletions(-)

diff --git a/llvm/include/llvm/Analysis/BasicAliasAnalysis.h b/llvm/include/llvm/Analysis/BasicAliasAnalysis.h
index addfffa01061..14e4bded264a 100644
--- a/llvm/include/llvm/Analysis/BasicAliasAnalysis.h
+++ b/llvm/include/llvm/Analysis/BasicAliasAnalysis.h
@@ -233,6 +233,24 @@ FunctionPass *createBasicAAWrapperPass();
 /// populated to the best of our ability for a particular function when inside
 /// of a \c ModulePass or a \c CallGraphSCCPass.
 BasicAAResult createLegacyPMBasicAAResult(Pass &P, Function &F);
+
+/// This class is a functor to be used in legacy module or SCC passes for
+/// computing AA results for a function. We store the results in fields so that
+/// they live long enough to be queried, but we re-use them each time.
+class LegacyAARGetter {
+  Pass &P;
+  Optional<BasicAAResult> BAR;
+  Optional<AAResults> AAR;
+
+public:
+  LegacyAARGetter(Pass &P) : P(P) {}
+  AAResults &operator()(Function &F) {
+    BAR.emplace(createLegacyPMBasicAAResult(P, F));
+    AAR.emplace(createLegacyPMAAResults(P, F, *BAR));
+    return *AAR;
+  }
+};
+
 }
 
 #endif
diff --git a/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp b/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
index a67332d067a8..2e2f131f7edd 100644
--- a/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
+++ b/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
@@ -1001,16 +1001,7 @@ bool ArgPromotion::runOnSCC(CallGraphSCC &SCC) {
   // changes.
   CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();
 
-  // We compute dedicated AA results for each function in the SCC as needed. We
-  // use a lambda referencing external objects so that they live long enough to
-  // be queried, but we re-use them each time.
-  Optional<BasicAAResult> BAR;
-  Optional<AAResults> AAR;
-  auto AARGetter = [&](Function &F) -> AAResults & {
-    BAR.emplace(createLegacyPMBasicAAResult(*this, F));
-    AAR.emplace(createLegacyPMAAResults(*this, F, *BAR));
-    return *AAR;
-  };
+  LegacyAARGetter AARGetter(*this);
 
   bool Changed = false, LocalChange;
 
diff --git a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
index 740e9fb8b90d..02f2b303226c 100644
--- a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
@@ -174,7 +174,7 @@ static MemoryAccessKind checkFunctionMemoryAccess(Function &F, AAResults &AAR,
 
 /// Deduce readonly/readnone attributes for the SCC.
 template <typename AARGetterT>
-static bool addReadAttrs(const SCCNodeSet &SCCNodes, AARGetterT AARGetter) {
+static bool addReadAttrs(const SCCNodeSet &SCCNodes, AARGetterT &&AARGetter) {
   // Check if any of the functions in the SCC read or write memory.  If they
   // write memory then they can't be marked readnone or readonly.
   bool ReadsMemory = false;
@@ -1163,19 +1163,7 @@ static bool runImpl(CallGraphSCC &SCC, AARGetterT AARGetter) {
 bool PostOrderFunctionAttrsLegacyPass::runOnSCC(CallGraphSCC &SCC) {
   if (skipSCC(SCC))
     return false;
-
-  // We compute dedicated AA results for each function in the SCC as needed. We
-  // use a lambda referencing external objects so that they live long enough to
-  // be queried, but we re-use them each time.
-  Optional<BasicAAResult> BAR;
-  Optional<AAResults> AAR;
-  auto AARGetter = [&](Function &F) -> AAResults & {
-    BAR.emplace(createLegacyPMBasicAAResult(*this, F));
-    AAR.emplace(createLegacyPMAAResults(*this, F, *BAR));
-    return *AAR;
-  };
-
-  return runImpl(SCC, AARGetter);
+  return runImpl(SCC, LegacyAARGetter(*this));
 }
 
 namespace {
diff --git a/llvm/lib/Transforms/IPO/Inliner.cpp b/llvm/lib/Transforms/IPO/Inliner.cpp
index c7c7af7acfae..384e5750d37c 100644
--- a/llvm/lib/Transforms/IPO/Inliner.cpp
+++ b/llvm/lib/Transforms/IPO/Inliner.cpp
@@ -636,22 +636,12 @@ bool LegacyInlinerBase::inlineCalls(CallGraphSCC &SCC) {
   ACT = &getAnalysis<AssumptionCacheTracker>();
   PSI = getAnalysis<ProfileSummaryInfoWrapperPass>().getPSI();
   auto &TLI = getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
-  // We compute dedicated AA results for each function in the SCC as needed. We
-  // use a lambda referencing external objects so that they live long enough to
-  // be queried, but we re-use them each time.
-  Optional<BasicAAResult> BAR;
-  Optional<AAResults> AAR;
-  auto AARGetter = [&](Function &F) -> AAResults & {
-    BAR.emplace(createLegacyPMBasicAAResult(*this, F));
-    AAR.emplace(createLegacyPMAAResults(*this, F, *BAR));
-    return *AAR;
-  };
   auto GetAssumptionCache = [&](Function &F) -> AssumptionCache & {
     return ACT->getAssumptionCache(F);
   };
   return inlineCallsImpl(SCC, CG, GetAssumptionCache, PSI, TLI, InsertLifetime,
                          [this](CallSite CS) { return getInlineCost(CS); },
-                         AARGetter, ImportedFunctionsStats);
+                         LegacyAARGetter(*this), ImportedFunctionsStats);
 }
 
 /// Remove now-dead linkonce functions at the end of