[VPlan] Replace RdxDesc with RecurKind in VPReductionPHIRecipe (NFC).

Replace VPReductionPHIRecipe with RecurKind in VPReductionPHIRecipe, as
all VPlan analyses and codegen only require the recurrence kind. This
enables creating new VPReductionPHIRecipe directly in LV, without
needing to construction a whole RecurrenceDescriptor object.

Depends on
#141860
#141932
#142290
#142291

Author: fhahn

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -7238,8 +7238,6 @@ static void fixReductionScalarResumeWhenVectorizingEpilog(
 
   auto *EpiRedHeaderPhi =
       cast<VPReductionPHIRecipe>(EpiRedResult->getOperand(0));
-  const RecurrenceDescriptor &RdxDesc =
-      EpiRedHeaderPhi->getRecurrenceDescriptor();
   Value *MainResumeValue;
   if (auto *VPI = dyn_cast<VPInstruction>(EpiRedHeaderPhi->getStartValue())) {
     assert((VPI->getOpcode() == VPInstruction::Broadcast ||
@@ -7248,19 +7246,19 @@ static void fixReductionScalarResumeWhenVectorizingEpilog(
     MainResumeValue = VPI->getOperand(0)->getUnderlyingValue();
   } else
     MainResumeValue = EpiRedHeaderPhi->getStartValue()->getUnderlyingValue();
-  if (RecurrenceDescriptor::isAnyOfRecurrenceKind(
-          RdxDesc.getRecurrenceKind())) {
+  RecurKind Kind = EpiRedHeaderPhi->getRecurrenceKind();
+  if (RecurrenceDescriptor::isAnyOfRecurrenceKind(Kind)) {
     Value *StartV = EpiRedResult->getOperand(1)->getLiveInIRValue();
     (void)StartV;
+
     auto *Cmp = cast<ICmpInst>(MainResumeValue);
     assert(Cmp->getPredicate() == CmpInst::ICMP_NE &&
            "AnyOf expected to start with ICMP_NE");
     assert(Cmp->getOperand(1) == StartV &&
            "AnyOf expected to start by comparing main resume value to original "
            "start value");
     MainResumeValue = Cmp->getOperand(0);
-  } else if (RecurrenceDescriptor::isFindLastIVRecurrenceKind(
-                 RdxDesc.getRecurrenceKind())) {
+  } else if (RecurrenceDescriptor::isFindLastIVRecurrenceKind(Kind)) {
     Value *StartV = getStartValueFromReductionResult(EpiRedResult);
     using namespace llvm::PatternMatch;
     Value *Cmp, *OrigResumeV, *CmpOp;
@@ -9037,8 +9035,7 @@ void LoopVectorizationPlanner::adjustRecipesForReductions(
     if (!PhiR || !PhiR->isInLoop() || (MinVF.isScalar() && !PhiR->isOrdered()))
       continue;
 
-    const RecurrenceDescriptor &RdxDesc = PhiR->getRecurrenceDescriptor();
-    RecurKind Kind = RdxDesc.getRecurrenceKind();
+    RecurKind Kind = PhiR->getRecurrenceKind();
     assert(
         !RecurrenceDescriptor::isAnyOfRecurrenceKind(Kind) &&
         !RecurrenceDescriptor::isFindLastIVRecurrenceKind(Kind) &&
@@ -9144,6 +9141,8 @@ void LoopVectorizationPlanner::adjustRecipesForReductions(
       if (CM.blockNeedsPredicationForAnyReason(CurrentLinkI->getParent()))
         CondOp = RecipeBuilder.getBlockInMask(CurrentLink->getParent());
 
+      const RecurrenceDescriptor &RdxDesc = Legal->getReductionVars().lookup(
+          cast<PHINode>(PhiR->getUnderlyingInstr()));
       // Non-FP RdxDescs will have all fast math flags set, so clear them.
       FastMathFlags FMFs = isa<FPMathOperator>(CurrentLinkI)
                                ? RdxDesc.getFastMathFlags()
@@ -9174,7 +9173,8 @@ void LoopVectorizationPlanner::adjustRecipesForReductions(
     if (!PhiR)
       continue;
 
-    const RecurrenceDescriptor &RdxDesc = PhiR->getRecurrenceDescriptor();
+    const RecurrenceDescriptor &RdxDesc = Legal->getReductionVars().lookup(
+        cast<PHINode>(PhiR->getUnderlyingInstr()));
     Type *PhiTy = PhiR->getUnderlyingValue()->getType();
     // If tail is folded by masking, introduce selects between the phi
     // and the users outside the vector region of each reduction, at the
@@ -9811,14 +9811,9 @@ preparePlanForEpilogueVectorLoop(VPlan &Plan, Loop *L,
           }));
       ResumeV = cast<PHINode>(ReductionPhi->getUnderlyingInstr())
                     ->getIncomingValueForBlock(L->getLoopPreheader());
-      const RecurrenceDescriptor &RdxDesc =
-          ReductionPhi->getRecurrenceDescriptor();
-      RecurKind RK = RdxDesc.getRecurrenceKind();
+      RecurKind RK = ReductionPhi->getRecurrenceKind();
       if (RecurrenceDescriptor::isAnyOfRecurrenceKind(RK)) {
         Value *StartV = RdxResult->getOperand(1)->getLiveInIRValue();
-        assert(RdxDesc.getRecurrenceStartValue() == StartV &&
-               "start value from ComputeAnyOfResult must match");
-
         // VPReductionPHIRecipes for AnyOf reductions expect a boolean as
         // start value; compare the final value from the main vector loop
         // to the start value.
@@ -9827,9 +9822,6 @@ preparePlanForEpilogueVectorLoop(VPlan &Plan, Loop *L,
         ResumeV = Builder.CreateICmpNE(ResumeV, StartV);
       } else if (RecurrenceDescriptor::isFindLastIVRecurrenceKind(RK)) {
         Value *StartV = getStartValueFromReductionResult(RdxResult);
-        assert(RdxDesc.getRecurrenceStartValue() == StartV &&
-               "start value from ComputeFindLastIVResult must match");
-
         ToFrozen[StartV] = cast<PHINode>(ResumeV)->getIncomingValueForBlock(
             EPI.MainLoopIterationCountCheck);
 

llvm/lib/Transforms/Vectorize/VPlan.h

@@ -2173,7 +2173,7 @@ struct VPFirstOrderRecurrencePHIRecipe : public VPHeaderPHIRecipe {
 class VPReductionPHIRecipe : public VPHeaderPHIRecipe,
                              public VPUnrollPartAccessor<2> {
   /// Descriptor for the reduction.
-  const RecurrenceDescriptor &RdxDesc;
+  const RecurKind Kind;
 
   /// The phi is part of an in-loop reduction.
   bool IsInLoop;
@@ -2192,17 +2192,24 @@ class VPReductionPHIRecipe : public VPHeaderPHIRecipe,
                        VPValue &Start, bool IsInLoop = false,
                        bool IsOrdered = false, unsigned VFScaleFactor = 1)
       : VPHeaderPHIRecipe(VPDef::VPReductionPHISC, Phi, &Start),
-        RdxDesc(RdxDesc), IsInLoop(IsInLoop), IsOrdered(IsOrdered),
-        VFScaleFactor(VFScaleFactor) {
+        Kind(RdxDesc.getRecurrenceKind()), IsInLoop(IsInLoop),
+        IsOrdered(IsOrdered), VFScaleFactor(VFScaleFactor) {
+    assert((!IsOrdered || IsInLoop) && "IsOrdered requires IsInLoop");
+  }
+  VPReductionPHIRecipe(PHINode *Phi, RecurKind Kind, VPValue &Start,
+                       bool IsInLoop = false, bool IsOrdered = false,
+                       unsigned VFScaleFactor = 1)
+      : VPHeaderPHIRecipe(VPDef::VPReductionPHISC, Phi, &Start), Kind(Kind),
+        IsInLoop(IsInLoop), IsOrdered(IsOrdered), VFScaleFactor(VFScaleFactor) {
     assert((!IsOrdered || IsInLoop) && "IsOrdered requires IsInLoop");
   }
 
   ~VPReductionPHIRecipe() override = default;
 
   VPReductionPHIRecipe *clone() override {
     auto *R = new VPReductionPHIRecipe(cast<PHINode>(getUnderlyingInstr()),
-                                       RdxDesc, *getOperand(0), IsInLoop,
-                                       IsOrdered, VFScaleFactor);
+                                       getRecurrenceKind(), *getOperand(0),
+                                       IsInLoop, IsOrdered, VFScaleFactor);
     R->addOperand(getBackedgeValue());
     return R;
   }
@@ -2221,9 +2228,7 @@ class VPReductionPHIRecipe : public VPHeaderPHIRecipe,
              VPSlotTracker &SlotTracker) const override;
 #endif
 
-  const RecurrenceDescriptor &getRecurrenceDescriptor() const {
-    return RdxDesc;
-  }
+  RecurKind getRecurrenceKind() const { return Kind; }
 
   /// Returns true, if the phi is part of an ordered reduction.
   bool isOrdered() const { return IsOrdered; }

llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp

@@ -637,8 +637,7 @@ Value *VPInstruction::generate(VPTransformState &State) {
     // and will be removed by breaking up the recipe further.
     auto *PhiR = cast<VPReductionPHIRecipe>(getOperand(0));
     // Get its reduction variable descriptor.
-    const RecurrenceDescriptor &RdxDesc = PhiR->getRecurrenceDescriptor();
-    [[maybe_unused]] RecurKind RK = RdxDesc.getRecurrenceKind();
+    [[maybe_unused]] RecurKind RK = PhiR->getRecurrenceKind();
     assert(RecurrenceDescriptor::isFindLastIVRecurrenceKind(RK) &&
            "Unexpected reduction kind");
     assert(!PhiR->isInLoop() &&
@@ -662,9 +661,8 @@ Value *VPInstruction::generate(VPTransformState &State) {
     // and will be removed by breaking up the recipe further.
     auto *PhiR = cast<VPReductionPHIRecipe>(getOperand(0));
     // Get its reduction variable descriptor.
-    const RecurrenceDescriptor &RdxDesc = PhiR->getRecurrenceDescriptor();
 
-    RecurKind RK = RdxDesc.getRecurrenceKind();
+    RecurKind RK = PhiR->getRecurrenceKind();
     assert(!RecurrenceDescriptor::isFindLastIVRecurrenceKind(RK) &&
            "should be handled by ComputeFindLastIVResult");
 
@@ -690,9 +688,9 @@ Value *VPInstruction::generate(VPTransformState &State) {
         if (RecurrenceDescriptor::isMinMaxRecurrenceKind(RK))
           ReducedPartRdx = createMinMaxOp(Builder, RK, ReducedPartRdx, RdxPart);
         else
-          ReducedPartRdx =
-              Builder.CreateBinOp((Instruction::BinaryOps)RdxDesc.getOpcode(),
-                                  RdxPart, ReducedPartRdx, "bin.rdx");
+          ReducedPartRdx = Builder.CreateBinOp(
+              (Instruction::BinaryOps)RecurrenceDescriptor::getOpcode(RK),
+              RdxPart, ReducedPartRdx, "bin.rdx");
       }
     }
 

llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp

@@ -1713,8 +1713,7 @@ void VPlanTransforms::clearReductionWrapFlags(VPlan &Plan) {
     auto *PhiR = dyn_cast<VPReductionPHIRecipe>(&R);
     if (!PhiR)
       continue;
-    const RecurrenceDescriptor &RdxDesc = PhiR->getRecurrenceDescriptor();
-    RecurKind RK = RdxDesc.getRecurrenceKind();
+    RecurKind RK = PhiR->getRecurrenceKind();
     if (RK != RecurKind::Add && RK != RecurKind::Mul)
       continue;