Revert [SCEV] Fix isLoopEntryGuardedByCond usage

It causes buildbot failures. New added assert is fired.
It seems not all usages of isLoopEntryGuardedByCond are fixed.

llvm-svn: 323079

2 files changed, 10 insertions, 21 deletions

diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index e25247072c5..7a9fddfd10b 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -8669,8 +8669,7 @@ bool ScalarEvolution::isKnownPredicate(ICmpInst::Predicate Pred,
   bool RightGuarded = false;
   if (LAR) {
     const Loop *L = LAR->getLoop();
-    if (isAvailableAtLoopEntry(RHS, L) &&
-        isLoopEntryGuardedByCond(L, Pred, LAR->getStart(), RHS) &&
+    if (isLoopEntryGuardedByCond(L, Pred, LAR->getStart(), RHS) &&
         isLoopBackedgeGuardedByCond(L, Pred, LAR->getPostIncExpr(*this), RHS)) {
       if (!RAR) return true;
       LeftGuarded = true;
@@ -8678,8 +8677,7 @@ bool ScalarEvolution::isKnownPredicate(ICmpInst::Predicate Pred,
   }
   if (RAR) {
     const Loop *L = RAR->getLoop();
-    if (isAvailableAtLoopEntry(LHS, L) &&
-        isLoopEntryGuardedByCond(L, Pred, LHS, RAR->getStart()) &&
+    if (isLoopEntryGuardedByCond(L, Pred, LHS, RAR->getStart()) &&
         isLoopBackedgeGuardedByCond(L, Pred, LHS, RAR->getPostIncExpr(*this))) {
       if (!LAR) return true;
       RightGuarded = true;
@@ -9060,12 +9058,6 @@ bool
 ScalarEvolution::isLoopEntryGuardedByCond(const Loop *L,
                                           ICmpInst::Predicate Pred,
                                           const SCEV *LHS, const SCEV *RHS) {
-  // Both LHS and RHS must be available at loop entry.
-  assert(isAvailableAtLoopEntry(LHS, L) &&
-         "LHS is not available at Loop Entry");
-  assert(isAvailableAtLoopEntry(RHS, L) &&
-         "RHS is not available at Loop Entry");
-
   // Interpret a null as meaning no loop, where there is obviously no guard
   // (interprocedural conditions notwithstanding).
   if (!L) return false;
diff --git a/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp b/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
index 1af77d84f85..c8e58a1e93a 100644
--- a/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
@@ -934,9 +934,9 @@ LoopStructure::parseLoopStructure(ScalarEvolution &SE,
         return None;
       }
 
-      if (!SE.isAvailableAtLoopEntry(RightSCEV, &L) ||
-          !SE.isLoopEntryGuardedByCond(&L, BoundPred, IndVarStart,
-                                       SE.getAddExpr(RightSCEV, Step))) {
+      if (!SE.isLoopEntryGuardedByCond(
+              &L, BoundPred, IndVarStart,
+              SE.getAddExpr(RightSCEV, Step))) {
         FailureReason = "Induction variable start not bounded by upper limit";
         return None;
       }
@@ -948,8 +948,7 @@ LoopStructure::parseLoopStructure(ScalarEvolution &SE,
         RightValue = B.CreateAdd(RightValue, One);
       }
     } else {
-      if (!SE.isAvailableAtLoopEntry(RightSCEV, &L) ||
-          !SE.isLoopEntryGuardedByCond(&L, BoundPred, IndVarStart, RightSCEV)) {
+      if (!SE.isLoopEntryGuardedByCond(&L, BoundPred, IndVarStart, RightSCEV)) {
         FailureReason = "Induction variable start not bounded by upper limit";
         return None;
       }
@@ -1015,10 +1014,9 @@ LoopStructure::parseLoopStructure(ScalarEvolution &SE,
         return None;
       }
 
-      if (!SE.isAvailableAtLoopEntry(RightSCEV, &L) ||
-          !SE.isLoopEntryGuardedByCond(
-               &L, BoundPred, IndVarStart,
-               SE.getMinusSCEV(RightSCEV, SE.getOne(RightSCEV->getType())))) {
+      if (!SE.isLoopEntryGuardedByCond(
+              &L, BoundPred, IndVarStart,
+              SE.getMinusSCEV(RightSCEV, SE.getOne(RightSCEV->getType())))) {
         FailureReason = "Induction variable start not bounded by lower limit";
         return None;
       }
@@ -1030,8 +1028,7 @@ LoopStructure::parseLoopStructure(ScalarEvolution &SE,
         RightValue = B.CreateSub(RightValue, One);
       }
     } else {
-      if (!SE.isAvailableAtLoopEntry(RightSCEV, &L) ||
-          !SE.isLoopEntryGuardedByCond(&L, BoundPred, IndVarStart, RightSCEV)) {
+      if (!SE.isLoopEntryGuardedByCond(&L, BoundPred, IndVarStart, RightSCEV)) {
         FailureReason = "Induction variable start not bounded by lower limit";
         return None;
       }