vendor/llvm/llvm-trunk-r300422

1 files changed, 30 insertions, 1 deletions

diff --git a/include/llvm/Analysis/Loads.h b/include/llvm/Analysis/Loads.h
index e167f36219d2..a59c1f88e229 100644
--- a/include/llvm/Analysis/Loads.h
+++ b/include/llvm/Analysis/Loads.h
@@ -85,8 +85,37 @@ Value *FindAvailableLoadedValue(LoadInst *Load,
                                 BasicBlock::iterator &ScanFrom,
                                 unsigned MaxInstsToScan = DefMaxInstsToScan,
                                 AliasAnalysis *AA = nullptr,
-                                bool *IsLoadCSE = nullptr);
+                                bool *IsLoadCSE = nullptr,
+                                unsigned *NumScanedInst = nullptr);
 
+/// Scan backwards to see if we have the value of the given pointer available
+/// locally within a small number of instructions.
+///
+/// You can use this function to scan across multiple blocks: after you call
+/// this function, if ScanFrom points at the beginning of the block, it's safe
+/// to continue scanning the predecessors.
+///
+/// \param Ptr The pointer we want the load and store to originate from.
+/// \param AccessTy The access type of the pointer.
+/// \param AtLeastAtomic Are we looking for at-least an atomic load/store ? In
+/// case it is false, we can return an atomic or non-atomic load or store. In
+/// case it is true, we need to return an atomic load or store.
+/// \param ScanBB The basic block to scan.
+/// \param [in,out] ScanFrom The location to start scanning from. When this
+/// function returns, it points at the last instruction scanned.
+/// \param MaxInstsToScan The maximum number of instructions to scan. If this
+/// is zero, the whole block will be scanned.
+/// \param AA Optional pointer to alias analysis, to make the scan more
+/// precise.
+/// \param [out] IsLoad Whether the returned value is a load from the same
+/// location in memory, as opposed to the value operand of a store.
+///
+/// \returns The found value, or nullptr if no value is found.
+Value *FindAvailablePtrLoadStore(Value *Ptr, Type *AccessTy, bool AtLeastAtomic,
+                                 BasicBlock *ScanBB,
+                                 BasicBlock::iterator &ScanFrom,
+                                 unsigned MaxInstsToScan, AliasAnalysis *AA,
+                                 bool *IsLoad, unsigned *NumScanedInst);
 }
 
 #endif