Rename isLoopGuardedByCond to isLoopEntryGuardedByCond, to emphasise
that it's only testing for the entry condition, not full loop-invariant
conditions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100979 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Analysis/ScalarEvolution.h b/include/llvm/Analysis/ScalarEvolution.h
index ab13a9d..bcd0806 100644
--- a/include/llvm/Analysis/ScalarEvolution.h
+++ b/include/llvm/Analysis/ScalarEvolution.h
@@ -554,11 +554,11 @@
     /// getSCEVAtScope(getSCEV(V), L).
     const SCEV *getSCEVAtScope(Value *V, const Loop *L);
 
-    /// isLoopGuardedByCond - Test whether entry to the loop is protected by
-    /// a conditional between LHS and RHS.  This is used to help avoid max
+    /// isLoopEntryGuardedByCond - Test whether entry to the loop is protected
+    /// by a conditional between LHS and RHS.  This is used to help avoid max
     /// expressions in loop trip counts, and to eliminate casts.
-    bool isLoopGuardedByCond(const Loop *L, ICmpInst::Predicate Pred,
-                             const SCEV *LHS, const SCEV *RHS);
+    bool isLoopEntryGuardedByCond(const Loop *L, ICmpInst::Predicate Pred,
+                                  const SCEV *LHS, const SCEV *RHS);
 
     /// isLoopBackedgeGuardedByCond - Test whether the backedge of the loop is
     /// protected by a conditional between LHS and RHS.  This is used to
diff --git a/lib/Analysis/PointerTracking.cpp b/lib/Analysis/PointerTracking.cpp
index ce7ac89..14df0b7 100644
--- a/lib/Analysis/PointerTracking.cpp
+++ b/lib/Analysis/PointerTracking.cpp
@@ -183,17 +183,17 @@
                                                    Predicate Pred,
                                                    const SCEV *A,
                                                    const SCEV *B) const {
-  if (SE->isLoopGuardedByCond(L, Pred, A, B))
+  if (SE->isLoopEntryGuardedByCond(L, Pred, A, B))
     return AlwaysTrue;
   Pred = ICmpInst::getSwappedPredicate(Pred);
-  if (SE->isLoopGuardedByCond(L, Pred, B, A))
+  if (SE->isLoopEntryGuardedByCond(L, Pred, B, A))
     return AlwaysTrue;
 
   Pred = ICmpInst::getInversePredicate(Pred);
-  if (SE->isLoopGuardedByCond(L, Pred, B, A))
+  if (SE->isLoopEntryGuardedByCond(L, Pred, B, A))
     return AlwaysFalse;
   Pred = ICmpInst::getSwappedPredicate(Pred);
-  if (SE->isLoopGuardedByCond(L, Pred, A, B))
+  if (SE->isLoopEntryGuardedByCond(L, Pred, A, B))
     return AlwaysTrue;
   return Unknown;
 }
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 41c8550..c67cb71 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -955,7 +955,7 @@
           const SCEV *N = getConstant(APInt::getMinValue(BitWidth) -
                                       getUnsignedRange(Step).getUnsignedMax());
           if (isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_ULT, AR, N) ||
-              (isLoopGuardedByCond(L, ICmpInst::ICMP_ULT, Start, N) &&
+              (isLoopEntryGuardedByCond(L, ICmpInst::ICMP_ULT, Start, N) &&
                isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_ULT,
                                            AR->getPostIncExpr(*this), N)))
             // Return the expression with the addrec on the outside.
@@ -966,7 +966,7 @@
           const SCEV *N = getConstant(APInt::getMaxValue(BitWidth) -
                                       getSignedRange(Step).getSignedMin());
           if (isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_UGT, AR, N) &&
-              (isLoopGuardedByCond(L, ICmpInst::ICMP_UGT, Start, N) ||
+              (isLoopEntryGuardedByCond(L, ICmpInst::ICMP_UGT, Start, N) ||
                isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_UGT,
                                            AR->getPostIncExpr(*this), N)))
             // Return the expression with the addrec on the outside.
@@ -1090,7 +1090,7 @@
           const SCEV *N = getConstant(APInt::getSignedMinValue(BitWidth) -
                                       getSignedRange(Step).getSignedMax());
           if (isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_SLT, AR, N) ||
-              (isLoopGuardedByCond(L, ICmpInst::ICMP_SLT, Start, N) &&
+              (isLoopEntryGuardedByCond(L, ICmpInst::ICMP_SLT, Start, N) &&
                isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_SLT,
                                            AR->getPostIncExpr(*this), N)))
             // Return the expression with the addrec on the outside.
@@ -1101,7 +1101,7 @@
           const SCEV *N = getConstant(APInt::getSignedMaxValue(BitWidth) -
                                       getSignedRange(Step).getSignedMin());
           if (isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_SGT, AR, N) ||
-              (isLoopGuardedByCond(L, ICmpInst::ICMP_SGT, Start, N) &&
+              (isLoopEntryGuardedByCond(L, ICmpInst::ICMP_SGT, Start, N) &&
                isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_SGT,
                                            AR->getPostIncExpr(*this), N)))
             // Return the expression with the addrec on the outside.
@@ -4751,13 +4751,13 @@
                        LoopContinuePredicate->getSuccessor(0) != L->getHeader());
 }
 
-/// isLoopGuardedByCond - Test whether entry to the loop is protected
+/// isLoopEntryGuardedByCond - Test whether entry to the loop is protected
 /// by a conditional between LHS and RHS.  This is used to help avoid max
 /// expressions in loop trip counts, and to eliminate casts.
 bool
-ScalarEvolution::isLoopGuardedByCond(const Loop *L,
-                                     ICmpInst::Predicate Pred,
-                                     const SCEV *LHS, const SCEV *RHS) {
+ScalarEvolution::isLoopEntryGuardedByCond(const Loop *L,
+                                          ICmpInst::Predicate Pred,
+                                          const SCEV *LHS, const SCEV *RHS) {
   // Interpret a null as meaning no loop, where there is obviously no guard
   // (interprocedural conditions notwithstanding).
   if (!L) return false;
@@ -5154,10 +5154,10 @@
     // only know that it will execute (max(m,n)-n)/s times. In both cases,
     // the division must round up.
     const SCEV *End = RHS;
-    if (!isLoopGuardedByCond(L,
-                             isSigned ? ICmpInst::ICMP_SLT :
-                                        ICmpInst::ICMP_ULT,
-                             getMinusSCEV(Start, Step), RHS))
+    if (!isLoopEntryGuardedByCond(L,
+                                  isSigned ? ICmpInst::ICMP_SLT :
+                                             ICmpInst::ICMP_ULT,
+                                  getMinusSCEV(Start, Step), RHS))
       End = isSigned ? getSMaxExpr(RHS, Start)
                      : getUMaxExpr(RHS, Start);
 
diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp
index 1a58b66..f87d693 100644
--- a/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -147,7 +147,7 @@
       SE->getAddExpr(BackedgeTakenCount,
                      SE->getIntegerSCEV(1, BackedgeTakenCount->getType()));
     if ((isa<SCEVConstant>(N) && !N->isZero()) ||
-        SE->isLoopGuardedByCond(L, ICmpInst::ICMP_NE, N, Zero)) {
+        SE->isLoopEntryGuardedByCond(L, ICmpInst::ICMP_NE, N, Zero)) {
       // No overflow. Cast the sum.
       RHS = SE->getTruncateOrZeroExtend(N, IndVar->getType());
     } else {