#include "llvm/Instructions.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
+#include "llvm/IntrinsicInst.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/CallGraph.h"
#include "llvm/Analysis/MemoryBuiltins.h"
+#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/InstIterator.h"
#include "llvm/ADT/Statistic.h"
/// called from the specified call site. The call site may be null in which
/// case the most generic behavior of this function should be returned.
ModRefBehavior getModRefBehavior(const Function *F) {
+ ModRefBehavior Min = UnknownModRefBehavior;
+
if (FunctionRecord *FR = getFunctionInfo(F)) {
if (FR->FunctionEffect == 0)
- return DoesNotAccessMemory;
+ Min = DoesNotAccessMemory;
else if ((FR->FunctionEffect & Mod) == 0)
- return OnlyReadsMemory;
+ Min = OnlyReadsMemory;
}
- return AliasAnalysis::getModRefBehavior(F);
+
+ return ModRefBehavior(AliasAnalysis::getModRefBehavior(F) & Min);
}
/// getModRefBehavior - Return the behavior of the specified function if
/// called from the specified call site. The call site may be null in which
/// case the most generic behavior of this function should be returned.
ModRefBehavior getModRefBehavior(ImmutableCallSite CS) {
- const Function* F = CS.getCalledFunction();
- if (!F) return AliasAnalysis::getModRefBehavior(CS);
- if (FunctionRecord *FR = getFunctionInfo(F)) {
- if (FR->FunctionEffect == 0)
- return DoesNotAccessMemory;
- else if ((FR->FunctionEffect & Mod) == 0)
- return OnlyReadsMemory;
- }
- return AliasAnalysis::getModRefBehavior(CS);
+ ModRefBehavior Min = UnknownModRefBehavior;
+
+ if (const Function* F = CS.getCalledFunction())
+ if (FunctionRecord *FR = getFunctionInfo(F)) {
+ if (FR->FunctionEffect == 0)
+ Min = DoesNotAccessMemory;
+ else if ((FR->FunctionEffect & Mod) == 0)
+ Min = OnlyReadsMemory;
+ }
+
+ return ModRefBehavior(AliasAnalysis::getModRefBehavior(CS) & Min);
}
virtual void deleteValue(Value *V);
virtual void copyValue(Value *From, Value *To);
+ virtual void addEscapingUse(Use &U);
/// getAdjustedAnalysisPointer - This method is used when a pass implements
/// an analysis interface through multiple inheritance. If needed, it
} else if (BitCastInst *BCI = dyn_cast<BitCastInst>(U)) {
if (AnalyzeUsesOfPointer(BCI, Readers, Writers, OkayStoreDest))
return true;
- } else if (isFreeCall(U)) {
+ } else if (isFreeCall(U, TLI)) {
Writers.push_back(cast<Instruction>(U)->getParent()->getParent());
} else if (CallInst *CI = dyn_cast<CallInst>(U)) {
// Make sure that this is just the function being called, not that it is
continue;
// Check the value being stored.
- Value *Ptr = SI->getOperand(0)->getUnderlyingObject();
-
- if (isMalloc(Ptr)) {
- // Okay, easy case.
- } else if (CallInst *CI = dyn_cast<CallInst>(Ptr)) {
- Function *F = CI->getCalledFunction();
- if (!F || !F->isDeclaration()) return false; // Too hard to analyze.
- if (F->getName() != "calloc") return false; // Not calloc.
- } else {
+ Value *Ptr = GetUnderlyingObject(SI->getOperand(0));
+
+ if (!isAllocLikeFn(Ptr, TLI))
return false; // Too hard to analyze.
- }
// Analyze all uses of the allocation. If any of them are used in a
// non-simple way (e.g. stored to another global) bail out.
for (inst_iterator II = inst_begin(SCC[i]->getFunction()),
E = inst_end(SCC[i]->getFunction());
II != E && FunctionEffect != ModRef; ++II)
- if (isa<LoadInst>(*II)) {
+ if (LoadInst *LI = dyn_cast<LoadInst>(&*II)) {
FunctionEffect |= Ref;
- if (cast<LoadInst>(*II).isVolatile())
+ if (LI->isVolatile())
// Volatile loads may have side-effects, so mark them as writing
// memory (for example, a flag inside the processor).
FunctionEffect |= Mod;
- } else if (isa<StoreInst>(*II)) {
+ } else if (StoreInst *SI = dyn_cast<StoreInst>(&*II)) {
FunctionEffect |= Mod;
- if (cast<StoreInst>(*II).isVolatile())
+ if (SI->isVolatile())
// Treat volatile stores as reading memory somewhere.
FunctionEffect |= Ref;
- } else if (isMalloc(&cast<Instruction>(*II)) ||
- isFreeCall(&cast<Instruction>(*II))) {
+ } else if (isAllocationFn(&*II, TLI) || isFreeCall(&*II, TLI)) {
FunctionEffect |= ModRef;
+ } else if (IntrinsicInst *Intrinsic = dyn_cast<IntrinsicInst>(&*II)) {
+ // The callgraph doesn't include intrinsic calls.
+ Function *Callee = Intrinsic->getCalledFunction();
+ ModRefBehavior Behaviour = AliasAnalysis::getModRefBehavior(Callee);
+ FunctionEffect |= (Behaviour & ModRef);
}
if ((FunctionEffect & Mod) == 0)
GlobalsModRef::alias(const Location &LocA,
const Location &LocB) {
// Get the base object these pointers point to.
- const Value *UV1 = LocA.Ptr->getUnderlyingObject();
- const Value *UV2 = LocB.Ptr->getUnderlyingObject();
+ const Value *UV1 = GetUnderlyingObject(LocA.Ptr);
+ const Value *UV2 = GetUnderlyingObject(LocB.Ptr);
// If either of the underlying values is a global, they may be non-addr-taken
// globals, which we can answer queries about.
// If we are asking for mod/ref info of a direct call with a pointer to a
// global we are tracking, return information if we have it.
if (const GlobalValue *GV =
- dyn_cast<GlobalValue>(Loc.Ptr->getUnderlyingObject()))
+ dyn_cast<GlobalValue>(GetUnderlyingObject(Loc.Ptr)))
if (GV->hasLocalLinkage())
if (const Function *F = CS.getCalledFunction())
if (NonAddressTakenGlobals.count(GV))
void GlobalsModRef::copyValue(Value *From, Value *To) {
AliasAnalysis::copyValue(From, To);
}
+
+void GlobalsModRef::addEscapingUse(Use &U) {
+ // For the purposes of this analysis, it is conservatively correct to treat
+ // a newly escaping value equivalently to a deleted one. We could perhaps
+ // be more precise by processing the new use and attempting to update our
+ // saved analysis results to accommodate it.
+ deleteValue(U);
+
+ AliasAnalysis::addEscapingUse(U);
+}