Make visible isDereferenceableAndAlignedPointer(..., const APInt &Size, ...)

[vitalybuka]

Summary

Used by D34311 and D34467

[efriedma]

LGTM.

llvm/trunk/include/llvm/Analysis/Loads.h

 /// greater or equal than requested. If the context instruction is specified
 /// performs context-sensitive analysis and returns true if the pointer is
 /// dereferenceable at the specified instruction.
 bool isDereferenceableAndAlignedPointer(const Value *V, unsigned Align,
                                         const DataLayout &DL,
                                         const Instruction *CtxI = nullptr,
                                         const DominatorTree *DT = nullptr);
 
+/// Returns true if V is always dereferenceable for Size byte with alignment
+/// greater or equal than requested. If the context instruction is specified
+/// performs context-sensitive analysis and returns true if the pointer is
+/// dereferenceable at the specified instruction.
+bool isDereferenceableAndAlignedPointer(const Value *V, unsigned Align,
+                                        const APInt &Size, const DataLayout &DL,
+                                        const Instruction *CtxI = nullptr,
+                                        const DominatorTree *DT = nullptr);
+
 /// Return true if we know that executing a load from this value cannot trap.
 ///
 /// If DT and ScanFrom are specified this method performs context-sensitive
 /// analysis and returns true if it is safe to load immediately before ScanFrom.
 ///
 /// If it is not obviously safe to load from the specified pointer, we do a
 /// quick local scan of the basic block containing ScanFrom, to determine if
 /// the address is already accessed.

llvm/trunk/lib/Analysis/Loads.cpp

if (const Value *RV = CS.getReturnedArgOperand())
       return isDereferenceableAndAlignedPointer(RV, Align, Size, DL, CtxI, DT,
                                                 Visited);
 
   // If we don't know, assume the worst.
   return false;
 }
 
 bool llvm::isDereferenceableAndAlignedPointer(const Value *V, unsigned Align,
+                                              const APInt &Size,
+                                              const DataLayout &DL,
+                                              const Instruction *CtxI,
+                                              const DominatorTree *DT) {
+  SmallPtrSet<const Value *, 32> Visited;
+  return ::isDereferenceableAndAlignedPointer(V, Align, Size, DL, CtxI, DT,
+                                              Visited);
+}
+
+bool llvm::isDereferenceableAndAlignedPointer(const Value *V, unsigned Align,
                                               const DataLayout &DL,
                                               const Instruction *CtxI,
                                               const DominatorTree *DT) {
   // When dereferenceability information is provided by a dereferenceable
   // attribute, we know exactly how many bytes are dereferenceable. If we can
   // determine the exact offset to the attributed variable, we can use that
   // information here.
   Type *VTy = V->getType();