[LV] Use GeneratedRTChecks to check if safety checks were added (NFC).

Directly check via GeneratedRTChecks if any checks have been added,
instead of needing to go through ILV. This simplifies the code and
enables further refactoring in follow-up patches.

Author: fhahn

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -505,9 +505,6 @@ class InnerLoopVectorizer {
   /// Fix the vectorized code, taking care of header phi's, and more.
   void fixVectorizedLoop(VPTransformState &State);
 
-  // Return true if any runtime check is added.
-  bool areSafetyChecksAdded() { return AddedSafetyChecks; }
-
   /// Fix the non-induction PHIs in \p Plan.
   void fixNonInductionPHIs(VPTransformState &State);
 
@@ -620,9 +617,6 @@ class InnerLoopVectorizer {
   /// The profitablity analysis.
   LoopVectorizationCostModel *Cost;
 
-  // Record whether runtime checks are added.
-  bool AddedSafetyChecks = false;
-
   /// BFI and PSI are used to check for profile guided size optimizations.
   BlockFrequencyInfo *BFI;
   ProfileSummaryInfo *PSI;
@@ -1777,6 +1771,9 @@ class GeneratedRTChecks {
   /// they have been used.
   Value *MemRuntimeCheckCond = nullptr;
 
+  /// True if any checks have been added.
+  bool AddedAnyChecks = false;
+
   DominatorTree *DT;
   LoopInfo *LI;
   TargetTransformInfo *TTI;
@@ -2038,9 +2035,9 @@ class GeneratedRTChecks {
     if (AddBranchWeights)
       setBranchWeights(BI, SCEVCheckBypassWeights, /*IsExpected=*/false);
     ReplaceInstWithInst(SCEVCheckBlock->getTerminator(), &BI);
-
     // Mark the check as used, to prevent it from being removed during cleanup.
     SCEVCheckCond = nullptr;
+    AddedAnyChecks = true;
     return SCEVCheckBlock;
   }
 
@@ -2070,8 +2067,12 @@ class GeneratedRTChecks {
 
     // Mark the check as used, to prevent it from being removed during cleanup.
     MemRuntimeCheckCond = nullptr;
+    AddedAnyChecks = true;
     return MemCheckBlock;
   }
+
+  /// Return true if any runtime checks have been added
+  bool hasChecks() const { return AddedAnyChecks; }
 };
 } // namespace
 
@@ -2459,7 +2460,6 @@ BasicBlock *InnerLoopVectorizer::emitSCEVChecks(BasicBlock *Bypass) {
   assert((!Cost->OptForSize ||
           Cost->Hints->getForce() == LoopVectorizeHints::FK_Enabled) &&
          "Cannot SCEV check stride or overflow when optimizing for size");
-  AddedSafetyChecks = true;
 
   introduceCheckBlockInVPlan(SCEVCheckBlock);
   return SCEVCheckBlock;
@@ -2494,9 +2494,6 @@ BasicBlock *InnerLoopVectorizer::emitMemRuntimeChecks(BasicBlock *Bypass) {
     });
   }
 
-
-  AddedSafetyChecks = true;
-
   introduceCheckBlockInVPlan(MemCheckBlock);
   return MemCheckBlock;
 }
@@ -10287,7 +10284,7 @@ bool LoopVectorizePass::processLoop(Loop *L) {
         }
         ++LoopsEpilogueVectorized;
 
-        if (!MainILV.areSafetyChecksAdded())
+        if (!Checks.hasChecks())
           DisableRuntimeUnroll = true;
       } else {
         InnerLoopVectorizer LB(L, PSE, LI, DT, TLI, TTI, AC, ORE, VF.Width,
@@ -10299,7 +10296,7 @@ bool LoopVectorizePass::processLoop(Loop *L) {
         // Add metadata to disable runtime unrolling a scalar loop when there
         // are no runtime checks about strides and memory. A scalar loop that is
         // rarely used is not worth unrolling.
-        if (!LB.areSafetyChecksAdded())
+        if (!Checks.hasChecks())
           DisableRuntimeUnroll = true;
       }
       // Report the vectorization decision.