Fold isCompatibleToEVLTransform into addExplicitVectorLength

Author: arcbbb

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -8539,20 +8539,6 @@ VPRecipeBuilder::tryToCreateWidenRecipe(Instruction *Instr,
   return tryToWiden(Instr, Operands, VPBB);
 }
 
-// EVL transform doesn't support backends where EVL diffs from RuntimeVF
-// in the second-to-last iteration.
-// Return false if the vector region has recipes relying on
-// RuntimeVF.
-static bool isCompatibleToEVLTransform(VPlan &Plan) {
-  if (any_of(Plan.getVectorLoopRegion()->getEntryBasicBlock()->phis(),
-             [](VPRecipeBase &Phi) {
-               return (isa<VPWidenIntOrFpInductionRecipe>(&Phi) ||
-                       isa<VPWidenPointerInductionRecipe>(&Phi));
-             }))
-    return false;
-  return true;
-}
-
 void LoopVectorizationPlanner::buildVPlansWithVPRecipes(ElementCount MinVF,
                                                         ElementCount MaxVF) {
   assert(OrigLoop->isInnermost() && "Inner loop expected.");
@@ -8567,12 +8553,10 @@ void LoopVectorizationPlanner::buildVPlansWithVPRecipes(ElementCount MinVF,
             *Plan, CM.getMinimalBitwidths(), PSE.getSE()->getContext());
       VPlanTransforms::optimize(*Plan, *PSE.getSE());
       // TODO: try to put it close to addActiveLaneMask().
-      if (CM.foldTailWithEVL()) {
-        // Discard the plan if it is not EVL-compatible
-        if (!isCompatibleToEVLTransform(*Plan))
-          break;
-        VPlanTransforms::addExplicitVectorLength(*Plan);
-      }
+      // Discard the plan if it is not EVL-compatible
+      if (CM.foldTailWithEVL() &&
+          !VPlanTransforms::addExplicitVectorLength(*Plan))
+        break;
       assert(verifyVPlanIsValid(*Plan) && "VPlan is invalid");
       VPlans.push_back(std::move(Plan));
     }

llvm/lib/Transforms/Vectorize/VPlan.h

@@ -1576,7 +1576,6 @@ class VPVectorPointerRecipe : public VPRecipeWithIRFlags {
 
   void execute(VPTransformState &State) override;
 
-  bool isReverse() { return IsReverse; }
   bool onlyFirstLaneUsed(const VPValue *Op) const override {
     assert(is_contained(operands(), Op) &&
            "Op must be an operand of the recipe");

llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp

@@ -1306,7 +1306,16 @@ void VPlanTransforms::addActiveLaneMask(
 /// %NextEVLIV = add IVSize (cast i32 %VPEVVL to IVSize), %EVLPhi
 /// ...
 ///
-void VPlanTransforms::addExplicitVectorLength(VPlan &Plan) {
+bool VPlanTransforms::addExplicitVectorLength(VPlan &Plan) {
+  // EVL transform doesn't support backends where EVL diffs from RuntimeVF
+  // in the second-to-last iteration.
+  // Return false if any recipes rely on RuntimeVF.
+  if (any_of(Plan.getVectorLoopRegion()->getEntryBasicBlock()->phis(),
+             [](VPRecipeBase &Phi) {
+               return (isa<VPWidenIntOrFpInductionRecipe>(&Phi) ||
+                       isa<VPWidenPointerInductionRecipe>(&Phi));
+             }))
+    return false;
   VPBasicBlock *Header = Plan.getVectorLoopRegion()->getEntryBasicBlock();
   auto *CanonicalIVPHI = Plan.getCanonicalIV();
   VPValue *StartV = CanonicalIVPHI->getStartValue();
@@ -1367,6 +1376,7 @@ void VPlanTransforms::addExplicitVectorLength(VPlan &Plan) {
   CanonicalIVIncrement->setOperand(0, CanonicalIVPHI);
   // TODO: support unroll factor > 1.
   Plan.setUF(1);
+  return true;
 }
 
 void VPlanTransforms::dropPoisonGeneratingRecipes(

llvm/lib/Transforms/Vectorize/VPlanTransforms.h

@@ -104,7 +104,8 @@ struct VPlanTransforms {
   /// VPCanonicalIVPHIRecipe with a VPEVLBasedIVPHIRecipe.
   /// VPCanonicalIVPHIRecipe is only used to control the loop after
   /// this transformation.
-  static void addExplicitVectorLength(VPlan &Plan);
+  /// \returns true if the transformation succeeds, or false if it doesn't.
+  static bool addExplicitVectorLength(VPlan &Plan);
 };
 
 } // namespace llvm