Feed AA to the inliner and use AA->getModRefBehavior in AddAliasScopeMetadata

This feeds AA through the IFI structure into the inliner so that
AddAliasScopeMetadata can use AA->getModRefBehavior to figure out which
functions only access their arguments (instead of just hard-coding some
knowledge of memory intrinsics). Most of the information is only available from
BasicAA; this is important for preserving alias scoping information for
target-specific intrinsics when doing the noalias parameter attribute to
metadata conversion.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216866 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Transforms/Utils/Cloning.h

@@ -43,6 +43,7 @@ class DataLayout;
 class Loop;
 class LoopInfo;
 class AllocaInst;
+class AliasAnalysis;
 
 /// CloneModule - Return an exact copy of the specified module
 ///
@@ -157,13 +158,16 @@ void CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc,
 /// InlineFunction call, and records the auxiliary results produced by it.
 class InlineFunctionInfo {
 public:
-  explicit InlineFunctionInfo(CallGraph *cg = nullptr, const DataLayout *DL = nullptr)
-    : CG(cg), DL(DL) {}
+  explicit InlineFunctionInfo(CallGraph *cg = nullptr,
+                              const DataLayout *DL = nullptr,
+                              AliasAnalysis *AA = nullptr)
+    : CG(cg), DL(DL), AA(AA) {}
 
   /// CG - If non-null, InlineFunction will update the callgraph to reflect the
   /// changes it makes.
   CallGraph *CG;
   const DataLayout *DL;
+  AliasAnalysis *AA;
 
   /// StaticAllocas - InlineFunction fills this in with all static allocas that
   /// get copied into the caller.

lib/Transforms/IPO/InlineAlways.cpp

@@ -14,6 +14,7 @@
 
 #include "llvm/Transforms/IPO.h"
 #include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/Analysis/CallGraph.h"
 #include "llvm/Analysis/InlineCost.h"
 #include "llvm/IR/CallSite.h"
@@ -65,6 +66,7 @@ public:
 char AlwaysInliner::ID = 0;
 INITIALIZE_PASS_BEGIN(AlwaysInliner, "always-inline",
                 "Inliner for always_inline functions", false, false)
+INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
 INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(InlineCostAnalysis)
 INITIALIZE_PASS_END(AlwaysInliner, "always-inline",

lib/Transforms/IPO/InlineSimple.cpp

@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Transforms/IPO.h"
+#include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/Analysis/CallGraph.h"
 #include "llvm/Analysis/InlineCost.h"
 #include "llvm/IR/CallSite.h"
@@ -73,6 +74,7 @@ static int computeThresholdFromOptLevels(unsigned OptLevel,
 char SimpleInliner::ID = 0;
 INITIALIZE_PASS_BEGIN(SimpleInliner, "inline",
                 "Function Integration/Inlining", false, false)
+INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
 INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(InlineCostAnalysis)
 INITIALIZE_PASS_END(SimpleInliner, "inline",

lib/Transforms/IPO/Inliner.cpp

@@ -16,6 +16,7 @@
 #include "llvm/Transforms/IPO/InlinerPass.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/Analysis/CallGraph.h"
 #include "llvm/Analysis/InlineCost.h"
 #include "llvm/IR/CallSite.h"
@@ -74,6 +75,7 @@ Inliner::Inliner(char &ID, int Threshold, bool InsertLifetime)
 /// the call graph.  If the derived class implements this method, it should
 /// always explicitly call the implementation here.
 void Inliner::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.addRequired<AliasAnalysis>();
   CallGraphSCCPass::getAnalysisUsage(AU);
 }
 
@@ -442,6 +444,7 @@ bool Inliner::runOnSCC(CallGraphSCC &SCC) {
   DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
   const DataLayout *DL = DLP ? &DLP->getDataLayout() : nullptr;
   const TargetLibraryInfo *TLI = getAnalysisIfAvailable<TargetLibraryInfo>();
+  AliasAnalysis *AA = &getAnalysis<AliasAnalysis>();
 
   SmallPtrSet<Function*, 8> SCCFunctions;
   DEBUG(dbgs() << "Inliner visiting SCC:");
@@ -500,7 +503,7 @@ bool Inliner::runOnSCC(CallGraphSCC &SCC) {
 
   
   InlinedArrayAllocasTy InlinedArrayAllocas;
-  InlineFunctionInfo InlineInfo(&CG, DL);
+  InlineFunctionInfo InlineInfo(&CG, DL, AA);
   
   // Now that we have all of the call sites, loop over them and inline them if
   // it looks profitable to do so.

lib/Transforms/Utils/InlineFunction.cpp

@@ -394,7 +394,7 @@ static void CloneAliasScopeMetadata(CallSite CS, ValueToValueMapTy &VMap) {
 /// parameters with noalias metadata specifying the new scope, and tag all
 /// non-derived loads, stores and memory intrinsics with the new alias scopes.
 static void AddAliasScopeMetadata(CallSite CS, ValueToValueMapTy &VMap,
-                                  const DataLayout *DL) {
+                                  const DataLayout *DL, AliasAnalysis *AA) {
   if (!EnableNoAliasConversion)
     return;
 
@@ -458,6 +458,7 @@ static void AddAliasScopeMetadata(CallSite CS, ValueToValueMapTy &VMap,
       if (!NI)
         continue;
 
+      bool IsArgMemOnlyCall = false, IsFuncCall = false;
       SmallVector<const Value *, 2> PtrArgs;
 
       if (const LoadInst *LI = dyn_cast<LoadInst>(I))
@@ -477,22 +478,27 @@ static void AddAliasScopeMetadata(CallSite CS, ValueToValueMapTy &VMap,
         if (ICS.doesNotAccessMemory())
           continue;
 
+        IsFuncCall = true;
+        if (AA) {
+          AliasAnalysis::ModRefBehavior MRB = AA->getModRefBehavior(ICS);
+          if (MRB == AliasAnalysis::OnlyAccessesArgumentPointees ||
+              MRB == AliasAnalysis::OnlyReadsArgumentPointees)
+            IsArgMemOnlyCall = true;
+        }
+
         for (ImmutableCallSite::arg_iterator AI = ICS.arg_begin(),
-             AE = ICS.arg_end(); AI != AE; ++AI)
+             AE = ICS.arg_end(); AI != AE; ++AI) {
           // We need to check the underlying objects of all arguments, not just
           // the pointer arguments, because we might be passing pointers as
           // integers, etc.
-          // FIXME: If we know that the call only accesses pointer arguments,
+          // However, if we know that the call only accesses pointer arguments,
           // then we only need to check the pointer arguments.
-          PtrArgs.push_back(*AI);
-      }
+          if (IsArgMemOnlyCall && !(*AI)->getType()->isPointerTy())
+            continue;
 
-      bool IsFuncCall = isa<CallInst>(I) || isa<InvokeInst>(I);
-      // FIXME: We should have a way to access the
-      // IntrReadArgMem/IntrReadWriteArgMem properties of intrinsics, and we
-      // should have a way to determine that for regular functions too. For
-      // now, just do this for the memory intrinsics we understand.
-      bool IsArgMemOnlyCall = isa<MemIntrinsic>(I);
+          PtrArgs.push_back(*AI);
+        }
+      }
 
       // If we found no pointers, then this instruction is not suitable for
       // pairing with an instruction to receive aliasing metadata.
@@ -975,7 +981,7 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI,
     CloneAliasScopeMetadata(CS, VMap);
 
     // Add noalias metadata if necessary.
-    AddAliasScopeMetadata(CS, VMap, IFI.DL);
+    AddAliasScopeMetadata(CS, VMap, IFI.DL, IFI.AA);
   }
 
   // If there are any alloca instructions in the block that used to be the entry

test/Transforms/Inline/noalias-calls.ll

@@ -1,4 +1,4 @@
-; RUN: opt -inline -enable-noalias-to-md-conversion -S < %s | FileCheck %s
+; RUN: opt -basicaa -inline -enable-noalias-to-md-conversion -S < %s | FileCheck %s
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"