[AliasAnalysis] Second prototype to cache BasicAA / anyAA state.

Summary:
Adding contained caching to AliasAnalysis. BasicAA is currently the only one using it.

AA changes:
- This patch is pulling the caches from BasicAAResults to AAResults, meaning the getModRefInfo call benefits from the IsCapturedCache as well when in "batch mode".
- All AAResultBase implementations add the QueryInfo member to all APIs. AAResults APIs maintain wrapper APIs such that all alias()/getModRefInfo call sites are unchanged.
- AA now provides a BatchAAResults type as a wrapper to AAResults. It keeps the AAResults instance and a QueryInfo instantiated to batch mode. It delegates all work to the AAResults instance with the batched QueryInfo. More API wrappers may be needed in BatchAAResults; only the minimum needed is currently added.

MemorySSA changes:
- All walkers are now templated on the AA used (AliasAnalysis=AAResults or BatchAAResults).
- At build time, we optimize uses; now we create a local walker (lives only as long as OptimizeUses does) using BatchAAResults.
- All Walkers have an internal AA and only use that now, never the AA in MemorySSA. The Walkers receive the AA they will use when built.

- The walker we use for queries after the build is instantiated on AliasAnalysis and is built after building MemorySSA and setting AA.
- All static methods doing walking are now templated on AliasAnalysisType if they are used both during build and after. If used only during build, the method now only takes a BatchAAResults. If used only after build, the method now takes an AliasAnalysis.

Subscribers: sanjoy, arsenm, jvesely, nhaehnle, jlebar, george.burgess.iv, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59315

llvm-svn: 356783
diff --git a/llvm/lib/Analysis/GlobalsModRef.cpp b/llvm/lib/Analysis/GlobalsModRef.cpp
index 4649b30..c6f54c2 100644
--- a/llvm/lib/Analysis/GlobalsModRef.cpp
+++ b/llvm/lib/Analysis/GlobalsModRef.cpp
@@ -806,7 +806,8 @@
 /// other is some random pointer, we know there cannot be an alias, because the
 /// address of the global isn't taken.
 AliasResult GlobalsAAResult::alias(const MemoryLocation &LocA,
-                                   const MemoryLocation &LocB) {
+                                   const MemoryLocation &LocB,
+                                   AAQueryInfo &AAQI) {
   // Get the base object these pointers point to.
   const Value *UV1 = GetUnderlyingObject(LocA.Ptr, DL);
   const Value *UV2 = GetUnderlyingObject(LocB.Ptr, DL);
@@ -881,11 +882,12 @@
     if ((GV1 || GV2) && GV1 != GV2)
       return NoAlias;
 
-  return AAResultBase::alias(LocA, LocB);
+  return AAResultBase::alias(LocA, LocB, AAQI);
 }
 
 ModRefInfo GlobalsAAResult::getModRefInfoForArgument(const CallBase *Call,
-                                                     const GlobalValue *GV) {
+                                                     const GlobalValue *GV,
+                                                     AAQueryInfo &AAQI) {
   if (Call->doesNotAccessMemory())
     return ModRefInfo::NoModRef;
   ModRefInfo ConservativeResult =
@@ -901,7 +903,8 @@
     if (!all_of(Objects, isIdentifiedObject) &&
         // Try ::alias to see if all objects are known not to alias GV.
         !all_of(Objects, [&](Value *V) {
-          return this->alias(MemoryLocation(V), MemoryLocation(GV)) == NoAlias;
+          return this->alias(MemoryLocation(V), MemoryLocation(GV), AAQI) ==
+                 NoAlias;
         }))
       return ConservativeResult;
 
@@ -914,7 +917,8 @@
 }
 
 ModRefInfo GlobalsAAResult::getModRefInfo(const CallBase *Call,
-                                          const MemoryLocation &Loc) {
+                                          const MemoryLocation &Loc,
+                                          AAQueryInfo &AAQI) {
   ModRefInfo Known = ModRefInfo::ModRef;
 
   // If we are asking for mod/ref info of a direct call with a pointer to a
@@ -926,11 +930,11 @@
         if (NonAddressTakenGlobals.count(GV))
           if (const FunctionInfo *FI = getFunctionInfo(F))
             Known = unionModRef(FI->getModRefInfoForGlobal(*GV),
-                                getModRefInfoForArgument(Call, GV));
+                                getModRefInfoForArgument(Call, GV, AAQI));
 
   if (!isModOrRefSet(Known))
     return ModRefInfo::NoModRef; // No need to query other mod/ref analyses
-  return intersectModRef(Known, AAResultBase::getModRefInfo(Call, Loc));
+  return intersectModRef(Known, AAResultBase::getModRefInfo(Call, Loc, AAQI));
 }
 
 GlobalsAAResult::GlobalsAAResult(const DataLayout &DL,