diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Analysis/GlobalsModRef.cpp | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/llvm/lib/Analysis/GlobalsModRef.cpp b/llvm/lib/Analysis/GlobalsModRef.cpp index 86c2e501465..51a83d53277 100644 --- a/llvm/lib/Analysis/GlobalsModRef.cpp +++ b/llvm/lib/Analysis/GlobalsModRef.cpp @@ -376,6 +376,15 @@ bool GlobalsAAResult::AnalyzeUsesOfPointer(Value *V, } else { return true; // Argument of an unknown call. } + // If the Callee is not ReadNone, it may read the global, + // and if it is not ReadOnly, it may also write to it. + Function *CalleeF = CS.getCalledFunction(); + if (!CalleeF->doesNotAccessMemory()) { + if (Readers) + Readers->insert(CalleeF); + if (Writers && !CalleeF->onlyReadsMemory()) + Writers->insert(CalleeF); + } } } else if (ICmpInst *ICI = dyn_cast<ICmpInst>(I)) { if (!isa<ConstantPointerNull>(ICI->getOperand(1))) @@ -507,7 +516,7 @@ void GlobalsAAResult::AnalyzeCallGraph(CallGraph &CG, Module &M) { if (F->isDeclaration()) { // Try to get mod/ref behaviour from function attributes. - if (F->doesNotAccessMemory()) { + if (F->doesNotAccessMemory() || F->onlyAccessesInaccessibleMemory()) { // Can't do better than that! } else if (F->onlyReadsMemory()) { FI.addModRefInfo(MRI_Ref); @@ -515,6 +524,12 @@ void GlobalsAAResult::AnalyzeCallGraph(CallGraph &CG, Module &M) { // This function might call back into the module and read a global - // consider every global as possibly being read by this function. FI.setMayReadAnyGlobal(); + } else if (F->onlyAccessesArgMemory() || + F->onlyAccessesInaccessibleMemOrArgMem()) { + // This function may only access (read/write) memory pointed to by its + // arguments. If this pointer is to a global, this escaping use of the + // pointer is captured in AnalyzeUsesOfPointer(). + FI.addModRefInfo(MRI_ModRef); } else { FI.addModRefInfo(MRI_ModRef); // Can't say anything useful unless it's an intrinsic - they don't |
