[MemoryBuiltins] Add isMallocOrCallocLikeFn so BasicAA can check for both at the same time

[craig.topper]

Summary

BasicAA wants to know if a function is either a malloc or calloc like function. Currently we have to check both separately. This means both calls check if its an intrinsic, query TLI, check the nobuiltin attribute, scan the AllocationFnData, etc.

This patch adds a isMallocOrCallocLikeFn so we can go through all of the checks once per call.

This also changes the one other location I saw that called both together.

[george.burgess.iv]

if we get more of these, it might make sense to surface AllocType so the user can directly ask for whatever kind of function they want.

for now though, this patch LGTM. thanks!

llvm/trunk/include/llvm/Analysis/MemoryBuiltins.h

bool isMallocLikeFn(const Value *V, const TargetLibraryInfo *TLI,
                     bool LookThroughBitCast = false);
 
 /// \brief Tests if a value is a call or invoke to a library function that
 /// allocates zero-filled memory (such as calloc).
 bool isCallocLikeFn(const Value *V, const TargetLibraryInfo *TLI,
                     bool LookThroughBitCast = false);
 
 /// \brief Tests if a value is a call or invoke to a library function that
+/// allocates memory similar to malloc or calloc.
+bool isMallocOrCallocLikeFn(const Value *V, const TargetLibraryInfo *TLI,
+                            bool LookThroughBitCast = false);
+
+/// \brief Tests if a value is a call or invoke to a library function that
 /// allocates memory (either malloc, calloc, or strdup like).
 bool isAllocLikeFn(const Value *V, const TargetLibraryInfo *TLI,
                    bool LookThroughBitCast = false);
 
 //===----------------------------------------------------------------------===//
 //  malloc Call Utility Functions.
 //
 

llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp

ModRefInfo BasicAAResult::getModRefInfo(ImmutableCallSite CS,
 
   // If the CallSite is to malloc or calloc, we can assume that it doesn't
   // modify any IR visible value.  This is only valid because we assume these
   // routines do not read values visible in the IR.  TODO: Consider special
   // casing realloc and strdup routines which access only their arguments as
   // well.  Or alternatively, replace all of this with inaccessiblememonly once
   // that's implemented fully. 
   auto *Inst = CS.getInstruction();
-  if (isMallocLikeFn(Inst, &TLI) || isCallocLikeFn(Inst, &TLI)) {
+  if (isMallocOrCallocLikeFn(Inst, &TLI)) {
     // Be conservative if the accessed pointer may alias the allocation -
     // fallback to the generic handling below.
     if (getBestAAResults().alias(MemoryLocation(Inst), Loc) == NoAlias)
       return MRI_NoModRef;
   }
 
   // The semantics of memcpy intrinsics forbid overlap between their respective
   // operands, i.e., source and destination of any given memcpy must no-alias.

llvm/trunk/lib/Analysis/CFLGraph.h

void visitCallSite(CallSite CS) {
         addNode(Inst);
 
       // Check if Inst is a call to a library function that
       // allocates/deallocates
       // on the heap. Those kinds of functions do not introduce any aliases.
       // TODO: address other common library functions such as realloc(),
       // strdup(),
       // etc.
-      if (isMallocLikeFn(Inst, &TLI) || isCallocLikeFn(Inst, &TLI) ||
-          isFreeCall(Inst, &TLI))
+      if (isMallocOrCallocLikeFn(Inst, &TLI) || isFreeCall(Inst, &TLI))
         return;
 
       // TODO: Add support for noalias args/all the other fun function
       // attributes
       // that we can tack on.
       SmallVector<Function *, 4> Targets;
       if (getPossibleTargets(CS, Targets))
         if (tryInterproceduralAnalysis(CS, Targets))

llvm/trunk/lib/Analysis/MemoryBuiltins.cpp

 #define DEBUG_TYPE "memory-builtins"
 
 enum AllocType : uint8_t {
   OpNewLike          = 1<<0, // allocates; never returns null
   MallocLike         = 1<<1 | OpNewLike, // allocates; may return null
   CallocLike         = 1<<2, // allocates + bzero
   ReallocLike        = 1<<3, // reallocates
   StrDupLike         = 1<<4,
+  MallocOrCallocLike = MallocLike | CallocLike,
   AllocLike          = MallocLike | CallocLike | StrDupLike,
   AnyAlloc           = AllocLike | ReallocLike
 };
 
 struct AllocFnsTy {
   AllocType AllocTy;
   unsigned NumParams;
   // First and Second size parameters (or -1 if unused)

 /// \brief Tests if a value is a call or invoke to a library function that
 /// allocates zero-filled memory (such as calloc).
 bool llvm::isCallocLikeFn(const Value *V, const TargetLibraryInfo *TLI,
                           bool LookThroughBitCast) {
   return getAllocationData(V, CallocLike, TLI, LookThroughBitCast).hasValue();
 }
 
 /// \brief Tests if a value is a call or invoke to a library function that
+/// allocates memory similiar to malloc or calloc.
+bool llvm::isMallocOrCallocLikeFn(const Value *V, const TargetLibraryInfo *TLI,
+                                  bool LookThroughBitCast) {
+  return getAllocationData(V, MallocOrCallocLike, TLI,
+                           LookThroughBitCast).hasValue();
+}
+
+/// \brief Tests if a value is a call or invoke to a library function that
 /// allocates memory (either malloc, calloc, or strdup like).
 bool llvm::isAllocLikeFn(const Value *V, const TargetLibraryInfo *TLI,
                          bool LookThroughBitCast) {
   return getAllocationData(V, AllocLike, TLI, LookThroughBitCast).hasValue();
 }
 
 /// extractMallocCall - Returns the corresponding CallInst if the instruction
 /// is a malloc call.  Since CallInst::CreateMalloc() only creates calls, we