diff options
Diffstat (limited to 'llvm/lib')
-rw-r--r-- | llvm/lib/Analysis/AliasAnalysis.cpp | 21 | ||||
-rw-r--r-- | llvm/lib/Analysis/BasicAliasAnalysis.cpp | 16 |
2 files changed, 37 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/AliasAnalysis.cpp b/llvm/lib/Analysis/AliasAnalysis.cpp index 2571492118b..3e46fccc58d 100644 --- a/llvm/lib/Analysis/AliasAnalysis.cpp +++ b/llvm/lib/Analysis/AliasAnalysis.cpp @@ -150,6 +150,27 @@ AliasAnalysis::getModRefBehavior(CallSite CS, AliasAnalysis::ModRefBehavior AliasAnalysis::getModRefBehavior(Function *F, std::vector<PointerAccessInfo> *Info) { + if (F->isIntrinsic()) { + switch (F->getIntrinsicID()) { + case Intrinsic::atomic_cmp_swap: + case Intrinsic::atomic_load_add: + case Intrinsic::atomic_load_and: + case Intrinsic::atomic_load_max: + case Intrinsic::atomic_load_min: + case Intrinsic::atomic_load_nand: + case Intrinsic::atomic_load_or: + case Intrinsic::atomic_load_sub: + case Intrinsic::atomic_load_umax: + case Intrinsic::atomic_load_umin: + case Intrinsic::atomic_load_xor: + case Intrinsic::atomic_swap: + // CAS and related intrinsics only access their arguments. + return AliasAnalysis::AccessesArguments; + default: + break; + } + } + if (F->doesNotAccessMemory()) // Can't do better than this. return DoesNotAccessMemory; diff --git a/llvm/lib/Analysis/BasicAliasAnalysis.cpp b/llvm/lib/Analysis/BasicAliasAnalysis.cpp index ccbe338585d..317e9d9e2e7 100644 --- a/llvm/lib/Analysis/BasicAliasAnalysis.cpp +++ b/llvm/lib/Analysis/BasicAliasAnalysis.cpp @@ -256,6 +256,22 @@ bool BasicAliasAnalysis::pointsToConstantMemory(const Value *P) { // AliasAnalysis::ModRefResult BasicAliasAnalysis::getModRefInfo(CallSite CS, Value *P, unsigned Size) { + // If the function only accesses its arguments, it suffices to check that + // P does not alias any of those arguments. + if (AliasAnalysis::getModRefBehavior(CS, 0) == + AliasAnalysis::AccessesArguments) { + bool doesAlias = false; + for (CallSite::arg_iterator AI = CS.arg_begin(), AE = CS.arg_end(); + AI != AE; ++AI) + if (alias(*AI, ~0U, P, Size) != NoAlias) { + doesAlias = true; + break; + } + + if (!doesAlias) + return NoModRef; + } + if (!isa<Constant>(P)) { const Value *Object = P->getUnderlyingObject(); |