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, 3 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/Scalar/ScalarReplAggregates.cpp b/llvm/lib/Transforms/Scalar/ScalarReplAggregates.cpp
index 03fff1d..5b47ef9 100644
--- a/llvm/lib/Transforms/Scalar/ScalarReplAggregates.cpp
+++ b/llvm/lib/Transforms/Scalar/ScalarReplAggregates.cpp
@@ -1140,8 +1140,8 @@ public:
 /// the select can be loaded unconditionally.
 static bool isSafeSelectToSpeculate(SelectInst *SI) {
   const DataLayout &DL = SI->getModule()->getDataLayout();
-  bool TDerefable = SI->getTrueValue()->isDereferenceablePointer(DL);
-  bool FDerefable = SI->getFalseValue()->isDereferenceablePointer(DL);
+  bool TDerefable = isDereferenceablePointer(SI->getTrueValue(), DL);
+  bool FDerefable = isDereferenceablePointer(SI->getFalseValue(), DL);
 
   for (User *U : SI->users()) {
     LoadInst *LI = dyn_cast<LoadInst>(U);
@@ -1228,7 +1228,7 @@ static bool isSafePHIToSpeculate(PHINode *PN) {
 
     // If this pointer is always safe to load, or if we can prove that there is
     // already a load in the block, then we can move the load to the pred block.
-    if (InVal->isDereferenceablePointer(DL) ||
+    if (isDereferenceablePointer(InVal, DL) ||
         isSafeToLoadUnconditionally(InVal, Pred->getTerminator(), MaxAlign))
       continue;