Rename isKnownNotFullPoison to programUndefinedIfPoison; NFC

Summary:
programUndefinedIfPoison makes more sense, given what the function
does; and I'm about to add a function with a name similar to
isKnownNotFullPoison (so do the rename to avoid confusion).

Reviewers: broune, majnemer, bjarke.roune

Reviewed By: broune

Subscribers: mcrosier, llvm-commits, mzolotukhin

Differential Revision: https://reviews.llvm.org/D30444

llvm-svn: 301776

llvm/include/llvm/Analysis/ValueTracking.h

@@ -417,7 +417,7 @@ template <typename T> class ArrayRef;
   ///
   /// Note that this currently only considers the basic block that is
   /// the parent of I.
-  bool isKnownNotFullPoison(const Instruction *PoisonI);
+  bool programUndefinedIfFullPoison(const Instruction *PoisonI);
 
   /// \brief Specific patterns of select instructions we can match.
   enum SelectPatternFlavor {

llvm/lib/Analysis/ScalarEvolution.cpp

@@ -5029,7 +5029,8 @@ bool ScalarEvolution::isSCEVExprNeverPoison(const Instruction *I) {
     return false;
 
   // Only proceed if we can prove that I does not yield poison.
-  if (!isKnownNotFullPoison(I)) return false;
+  if (!programUndefinedIfFullPoison(I))
+    return false;
 
   // At this point we know that if I is executed, then it does not wrap
   // according to at least one of NSW or NUW. If I is not executed, then we do

llvm/lib/Analysis/ValueTracking.cpp

@@ -3841,7 +3841,7 @@ const Value *llvm::getGuaranteedNonFullPoisonOp(const Instruction *I) {
   }
 }
 
-bool llvm::isKnownNotFullPoison(const Instruction *PoisonI) {
+bool llvm::programUndefinedIfFullPoison(const Instruction *PoisonI) {
   // We currently only look for uses of poison values within the same basic
   // block, as that makes it easier to guarantee that the uses will be
   // executed given that PoisonI is executed.

llvm/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp

@@ -1138,7 +1138,7 @@ bool SeparateConstOffsetFromGEP::reuniteExts(Instruction *I) {
   // Add I to DominatingExprs if it's an add/sub that can't sign overflow.
   if (match(I, m_NSWAdd(m_Value(LHS), m_Value(RHS))) ||
       match(I, m_NSWSub(m_Value(LHS), m_Value(RHS)))) {
-    if (isKnownNotFullPoison(I)) {
+    if (programUndefinedIfFullPoison(I)) {
       const SCEV *Key =
           SE->getAddExpr(SE->getUnknown(LHS), SE->getUnknown(RHS));
       DominatingExprs[Key].push_back(I);

llvm/test/Analysis/ScalarEvolution/flags-from-poison.ll

@@ -205,7 +205,7 @@ exit:
   ret void
 }
 
-; Demonstrate why we need a Visited set in llvm::isKnownNotFullPoison.
+; Demonstrate why we need a Visited set in llvm::programUndefinedIfFullPoison.
 define void @test-add-not-header5(float* %input, i32 %offset) {
 ; CHECK-LABEL: @test-add-not-header5
 entry: