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

4 files changed, 9 insertions, 8 deletions

diff --git a/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp b/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
index eee5a6a..79e15bd 100644
--- a/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
+++ b/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
@@ -36,6 +36,7 @@
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/Analysis/CallGraph.h"
 #include "llvm/Analysis/CallGraphSCCPass.h"
+#include "llvm/Analysis/ValueTracking.h"
 #include "llvm/IR/CFG.h"
 #include "llvm/IR/CallSite.h"
 #include "llvm/IR/Constants.h"
@@ -321,7 +322,7 @@ static bool AllCallersPassInValidPointerForArgument(Argument *Arg) {
     CallSite CS(U);
     assert(CS && "Should only have direct calls!");
 
-    if (!CS.getArgument(ArgNo)->isDereferenceablePointer(DL))
+    if (!isDereferenceablePointer(CS.getArgument(ArgNo), DL))
       return false;
   }
   return true;
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 56b6cd3..1505ff0 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -1204,7 +1204,7 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) {
       II->addAttribute(AttributeSet::ReturnIndex, Attribute::NonNull);
 
     // isDereferenceablePointer -> deref attribute
-    if (DerivedPtr->isDereferenceablePointer(DL)) {
+    if (isDereferenceablePointer(DerivedPtr, DL)) {
       if (Argument *A = dyn_cast<Argument>(DerivedPtr)) {
         uint64_t Bytes = A->getDereferenceableBytes();
         II->addDereferenceableAttr(AttributeSet::ReturnIndex, Bytes);
diff --git a/llvm/lib/Transforms/Scalar/SROA.cpp b/llvm/lib/Transforms/Scalar/SROA.cpp
index e11ab33..66aed8d 100644
--- a/llvm/lib/Transforms/Scalar/SROA.cpp
+++ b/llvm/lib/Transforms/Scalar/SROA.cpp
@@ -1406,7 +1406,7 @@ 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, TI, MaxAlign))
       continue;
 
@@ -1476,8 +1476,8 @@ static bool isSafeSelectToSpeculate(SelectInst &SI) {
   Value *TValue = SI.getTrueValue();
   Value *FValue = SI.getFalseValue();
   const DataLayout &DL = SI.getModule()->getDataLayout();
-  bool TDerefable = TValue->isDereferenceablePointer(DL);
-  bool FDerefable = FValue->isDereferenceablePointer(DL);
+  bool TDerefable = isDereferenceablePointer(TValue, DL);
+  bool FDerefable = isDereferenceablePointer(FValue, DL);
 
   for (User *U : SI.users()) {
     LoadInst *LI = dyn_cast<LoadInst>(U);
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;