diff options
Diffstat (limited to 'lib/Analysis/Loads.cpp')
| -rw-r--r-- | lib/Analysis/Loads.cpp | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/lib/Analysis/Loads.cpp b/lib/Analysis/Loads.cpp index 0e6bcbf..873a275 100644 --- a/lib/Analysis/Loads.cpp +++ b/lib/Analysis/Loads.cpp @@ -17,6 +17,7 @@ #include "llvm/GlobalAlias.h" #include "llvm/GlobalVariable.h" #include "llvm/IntrinsicInst.h" +#include "llvm/LLVMContext.h" #include "llvm/Operator.h" using namespace llvm; @@ -160,10 +161,15 @@ bool llvm::isSafeToLoadUnconditionally(Value *V, Instruction *ScanFrom, /// MaxInstsToScan specifies the maximum instructions to scan in the block. If /// it is set to 0, it will scan the whole block. You can also optionally /// specify an alias analysis implementation, which makes this more precise. +/// +/// If TBAATag is non-null and a load or store is found, the TBAA tag from the +/// load or store is recorded there. If there is no TBAA tag or if no access +/// is found, it is left unmodified. Value *llvm::FindAvailableLoadedValue(Value *Ptr, BasicBlock *ScanBB, BasicBlock::iterator &ScanFrom, unsigned MaxInstsToScan, - AliasAnalysis *AA) { + AliasAnalysis *AA, + MDNode **TBAATag) { if (MaxInstsToScan == 0) MaxInstsToScan = ~0U; // If we're using alias analysis to disambiguate get the size of *Ptr. @@ -191,15 +197,19 @@ Value *llvm::FindAvailableLoadedValue(Value *Ptr, BasicBlock *ScanBB, // (This is true even if the load is volatile or atomic, although // those cases are unlikely.) if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) - if (AreEquivalentAddressValues(LI->getOperand(0), Ptr)) + if (AreEquivalentAddressValues(LI->getOperand(0), Ptr)) { + if (TBAATag) *TBAATag = LI->getMetadata(LLVMContext::MD_tbaa); return LI; + } if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) { // If this is a store through Ptr, the value is available! // (This is true even if the store is volatile or atomic, although // those cases are unlikely.) - if (AreEquivalentAddressValues(SI->getOperand(1), Ptr)) + if (AreEquivalentAddressValues(SI->getOperand(1), Ptr)) { + if (TBAATag) *TBAATag = SI->getMetadata(LLVMContext::MD_tbaa); return SI->getOperand(0); + } // If Ptr is an alloca and this is a store to a different alloca, ignore // the store. This is a trivial form of alias analysis that is important |