Move Value.isDereferenceablePointer to ValueTracking [NFC]

Move isDereferenceablePointer function to Analysis. This function recursively tracks dereferencability over a chain of values like other functions in ValueTracking.

This refactoring is motivated by further changes to support dereferenceable_or_null attribute (http://reviews.llvm.org/D8650). isDereferenceablePointer will be extended to perform context-sensitive analysis and IR is not a good place to have such functionality.

Patch by: Artur Pilipenko <apilipenko@azulsystems.com>
Differential Revision: reviews.llvm.org/D9075

llvm-svn: 235611

1 files changed, 2 insertions, 1 deletions

diff --git a/llvm/lib/Analysis/MemDerefPrinter.cpp b/llvm/lib/Analysis/MemDerefPrinter.cpp
index 6119a3d..5903dc5 100644
--- a/llvm/lib/Analysis/MemDerefPrinter.cpp
+++ b/llvm/lib/Analysis/MemDerefPrinter.cpp
@@ -10,6 +10,7 @@
 #include "llvm/Analysis/Passes.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/Analysis/MemoryDependenceAnalysis.h"
+#include "llvm/Analysis/ValueTracking.h"
 #include "llvm/IR/CallSite.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/InstIterator.h"
@@ -53,7 +54,7 @@ bool MemDerefPrinter::runOnFunction(Function &F) {
   for (auto &I: inst_range(F)) {
     if (LoadInst *LI = dyn_cast<LoadInst>(&I)) {
       Value *PO = LI->getPointerOperand();
-      if (PO->isDereferenceablePointer(DL))
+      if (isDereferenceablePointer(PO, DL))
         Vec.push_back(PO);
     }
   }