[VP] Refactor VectorBuilder to avoid layering violation. NFC (#99276)

Mel-Chen · web-flow · commit 6d12b3f67df4 · 2024-07-25T15:14:39.000+08:00
This patch refactors the handling of reduction to eliminate layering
violations.

* Introduced `getReductionIntrinsicID` in LoopUtils.h for mapping
recurrence kinds to llvm.vector.reduce.* intrinsic IDs.
* Updated `VectorBuilder::createSimpleTargetReduction` to accept
llvm.vector.reduce.* intrinsic directly.
* New function `VPIntrinsic::getForIntrinsic` for mapping intrinsic ID
to the same functional VP intrinsic ID.
diff --git a/llvm/include/llvm/IR/IntrinsicInst.h b/llvm/include/llvm/IR/IntrinsicInst.h
@@ -569,6 +569,10 @@ class VPIntrinsic : public IntrinsicInst {
   /// The llvm.vp.* intrinsics for this instruction Opcode
   static Intrinsic::ID getForOpcode(unsigned OC);
 
+  /// The llvm.vp.* intrinsics for this intrinsic ID \p Id. Return \p Id if it
+  /// is already a VP intrinsic.
+  static Intrinsic::ID getForIntrinsic(Intrinsic::ID Id);
+
   // Whether \p ID is a VP intrinsic ID.
   static bool isVPIntrinsic(Intrinsic::ID);
 
diff --git a/llvm/include/llvm/IR/VectorBuilder.h b/llvm/include/llvm/IR/VectorBuilder.h
@@ -15,7 +15,6 @@
 #ifndef LLVM_IR_VECTORBUILDER_H
 #define LLVM_IR_VECTORBUILDER_H
 
-#include <llvm/Analysis/IVDescriptors.h>
 #include <llvm/IR/IRBuilder.h>
 #include <llvm/IR/InstrTypes.h>
 #include <llvm/IR/Instruction.h>
@@ -100,11 +99,11 @@ class VectorBuilder {
                                  const Twine &Name = Twine());
 
   /// Emit a VP reduction intrinsic call for recurrence kind.
-  /// \param Kind        The kind of recurrence
+  /// \param RdxID       The intrinsic ID of llvm.vector.reduce.*
   /// \param ValTy       The type of operand which the reduction operation is
   ///                    performed.
   /// \param VecOpArray  The operand list.
-  Value *createSimpleTargetReduction(RecurKind Kind, Type *ValTy,
+  Value *createSimpleTargetReduction(Intrinsic::ID RdxID, Type *ValTy,
                                      ArrayRef<Value *> VecOpArray,
                                      const Twine &Name = Twine());
 };
diff --git a/llvm/include/llvm/Transforms/Utils/LoopUtils.h b/llvm/include/llvm/Transforms/Utils/LoopUtils.h
@@ -359,6 +359,10 @@ bool canSinkOrHoistInst(Instruction &I, AAResults *AA, DominatorTree *DT,
                         SinkAndHoistLICMFlags &LICMFlags,
                         OptimizationRemarkEmitter *ORE = nullptr);
 
+/// Returns the llvm.vector.reduce intrinsic that corresponds to the recurrence
+/// kind.
+constexpr Intrinsic::ID getReductionIntrinsicID(RecurKind RK);
+
 /// Returns the arithmetic instruction opcode used when expanding a reduction.
 unsigned getArithmeticReductionInstruction(Intrinsic::ID RdxID);
 
diff --git a/llvm/lib/IR/IntrinsicInst.cpp b/llvm/lib/IR/IntrinsicInst.cpp
@@ -599,6 +599,25 @@ Intrinsic::ID VPIntrinsic::getForOpcode(unsigned IROPC) {
   return Intrinsic::not_intrinsic;
 }
 
+constexpr static Intrinsic::ID getForIntrinsic(Intrinsic::ID Id) {
+  if (::isVPIntrinsic(Id))
+    return Id;
+
+  switch (Id) {
+  default:
+    break;
+#define BEGIN_REGISTER_VP_INTRINSIC(VPID, ...) break;
+#define VP_PROPERTY_FUNCTIONAL_INTRINSIC(INTRIN) case Intrinsic::INTRIN:
+#define END_REGISTER_VP_INTRINSIC(VPID) return Intrinsic::VPID;
+#include "llvm/IR/VPIntrinsics.def"
+  }
+  return Intrinsic::not_intrinsic;
+}
+
+Intrinsic::ID VPIntrinsic::getForIntrinsic(Intrinsic::ID Id) {
+  return ::getForIntrinsic(Id);
+}
+
 bool VPIntrinsic::canIgnoreVectorLengthParam() const {
   using namespace PatternMatch;
 
diff --git a/llvm/lib/IR/VectorBuilder.cpp b/llvm/lib/IR/VectorBuilder.cpp
@@ -60,60 +60,13 @@ Value *VectorBuilder::createVectorInstruction(unsigned Opcode, Type *ReturnTy,
   return createVectorInstructionImpl(VPID, ReturnTy, InstOpArray, Name);
 }
 
-Value *VectorBuilder::createSimpleTargetReduction(RecurKind Kind, Type *ValTy,
+Value *VectorBuilder::createSimpleTargetReduction(Intrinsic::ID RdxID,
+                                                  Type *ValTy,
                                                   ArrayRef<Value *> InstOpArray,
                                                   const Twine &Name) {
-  Intrinsic::ID VPID;
-  switch (Kind) {
-  case RecurKind::Add:
-    VPID = Intrinsic::vp_reduce_add;
-    break;
-  case RecurKind::Mul:
-    VPID = Intrinsic::vp_reduce_mul;
-    break;
-  case RecurKind::And:
-    VPID = Intrinsic::vp_reduce_and;
-    break;
-  case RecurKind::Or:
-    VPID = Intrinsic::vp_reduce_or;
-    break;
-  case RecurKind::Xor:
-    VPID = Intrinsic::vp_reduce_xor;
-    break;
-  case RecurKind::FMulAdd:
-  case RecurKind::FAdd:
-    VPID = Intrinsic::vp_reduce_fadd;
-    break;
-  case RecurKind::FMul:
-    VPID = Intrinsic::vp_reduce_fmul;
-    break;
-  case RecurKind::SMax:
-    VPID = Intrinsic::vp_reduce_smax;
-    break;
-  case RecurKind::SMin:
-    VPID = Intrinsic::vp_reduce_smin;
-    break;
-  case RecurKind::UMax:
-    VPID = Intrinsic::vp_reduce_umax;
-    break;
-  case RecurKind::UMin:
-    VPID = Intrinsic::vp_reduce_umin;
-    break;
-  case RecurKind::FMax:
-    VPID = Intrinsic::vp_reduce_fmax;
-    break;
-  case RecurKind::FMin:
-    VPID = Intrinsic::vp_reduce_fmin;
-    break;
-  case RecurKind::FMaximum:
-    VPID = Intrinsic::vp_reduce_fmaximum;
-    break;
-  case RecurKind::FMinimum:
-    VPID = Intrinsic::vp_reduce_fminimum;
-    break;
-  default:
-    llvm_unreachable("No VPIntrinsic for this reduction");
-  }
+  auto VPID = VPIntrinsic::getForIntrinsic(RdxID);
+  assert(VPReductionIntrinsic::isVPReduction(VPID) &&
+         "No VPIntrinsic for this reduction");
   return createVectorInstructionImpl(VPID, ValTy, InstOpArray, Name);
 }
 
diff --git a/llvm/lib/Transforms/Utils/LoopUtils.cpp b/llvm/lib/Transforms/Utils/LoopUtils.cpp
@@ -918,6 +918,44 @@ bool llvm::hasIterationCountInvariantInParent(Loop *InnerLoop,
   return true;
 }
 
+constexpr Intrinsic::ID llvm::getReductionIntrinsicID(RecurKind RK) {
+  switch (RK) {
+  default:
+    llvm_unreachable("Unexpected recurrence kind");
+  case RecurKind::Add:
+    return Intrinsic::vector_reduce_add;
+  case RecurKind::Mul:
+    return Intrinsic::vector_reduce_mul;
+  case RecurKind::And:
+    return Intrinsic::vector_reduce_and;
+  case RecurKind::Or:
+    return Intrinsic::vector_reduce_or;
+  case RecurKind::Xor:
+    return Intrinsic::vector_reduce_xor;
+  case RecurKind::FMulAdd:
+  case RecurKind::FAdd:
+    return Intrinsic::vector_reduce_fadd;
+  case RecurKind::FMul:
+    return Intrinsic::vector_reduce_fmul;
+  case RecurKind::SMax:
+    return Intrinsic::vector_reduce_smax;
+  case RecurKind::SMin:
+    return Intrinsic::vector_reduce_smin;
+  case RecurKind::UMax:
+    return Intrinsic::vector_reduce_umax;
+  case RecurKind::UMin:
+    return Intrinsic::vector_reduce_umin;
+  case RecurKind::FMax:
+    return Intrinsic::vector_reduce_fmax;
+  case RecurKind::FMin:
+    return Intrinsic::vector_reduce_fmin;
+  case RecurKind::FMaximum:
+    return Intrinsic::vector_reduce_fmaximum;
+  case RecurKind::FMinimum:
+    return Intrinsic::vector_reduce_fminimum;
+  }
+}
+
 unsigned llvm::getArithmeticReductionInstruction(Intrinsic::ID RdxID) {
   switch (RdxID) {
   case Intrinsic::vector_reduce_fadd:
@@ -1215,12 +1253,13 @@ Value *llvm::createSimpleTargetReduction(VectorBuilder &VBuilder, Value *Src,
   RecurKind Kind = Desc.getRecurrenceKind();
   assert(!RecurrenceDescriptor::isAnyOfRecurrenceKind(Kind) &&
          "AnyOf reduction is not supported.");
+  Intrinsic::ID Id = getReductionIntrinsicID(Kind);
   auto *SrcTy = cast<VectorType>(Src->getType());
   Type *SrcEltTy = SrcTy->getElementType();
   Value *Iden =
       Desc.getRecurrenceIdentity(Kind, SrcEltTy, Desc.getFastMathFlags());
   Value *Ops[] = {Iden, Src};
-  return VBuilder.createSimpleTargetReduction(Kind, SrcTy, Ops);
+  return VBuilder.createSimpleTargetReduction(Id, SrcTy, Ops);
 }
 
 Value *llvm::createTargetReduction(IRBuilderBase &B,
@@ -1260,9 +1299,10 @@ Value *llvm::createOrderedReduction(VectorBuilder &VBuilder,
   assert(Src->getType()->isVectorTy() && "Expected a vector type");
   assert(!Start->getType()->isVectorTy() && "Expected a scalar type");
 
+  Intrinsic::ID Id = getReductionIntrinsicID(RecurKind::FAdd);
   auto *SrcTy = cast<VectorType>(Src->getType());
   Value *Ops[] = {Start, Src};
-  return VBuilder.createSimpleTargetReduction(RecurKind::FAdd, SrcTy, Ops);
+  return VBuilder.createSimpleTargetReduction(Id, SrcTy, Ops);
 }
 
 void llvm::propagateIRFlags(Value *I, ArrayRef<Value *> VL, Value *OpValue,
diff --git a/llvm/unittests/IR/VPIntrinsicTest.cpp b/llvm/unittests/IR/VPIntrinsicTest.cpp
@@ -367,6 +367,59 @@ TEST_F(VPIntrinsicTest, IntrinsicIDRoundTrip) {
   ASSERT_NE(FullTripCounts, 0u);
 }
 
+/// Check that going from intrinsic to VP intrinsic and back results in the same
+/// intrinsic.
+TEST_F(VPIntrinsicTest, IntrinsicToVPRoundTrip) {
+  bool IsFullTrip = false;
+  Intrinsic::ID IntrinsicID = Intrinsic::not_intrinsic + 1;
+  for (; IntrinsicID < Intrinsic::num_intrinsics; IntrinsicID++) {
+    Intrinsic::ID VPID = VPIntrinsic::getForIntrinsic(IntrinsicID);
+    // No equivalent VP intrinsic available.
+    if (VPID == Intrinsic::not_intrinsic)
+      continue;
+
+    // Return itself if passed intrinsic ID is VP intrinsic.
+    if (VPIntrinsic::isVPIntrinsic(IntrinsicID)) {
+      ASSERT_EQ(IntrinsicID, VPID);
+      continue;
+    }
+
+    std::optional<Intrinsic::ID> RoundTripIntrinsicID =
+        VPIntrinsic::getFunctionalIntrinsicIDForVP(VPID);
+    // No equivalent non-predicated intrinsic available.
+    if (!RoundTripIntrinsicID)
+      continue;
+
+    ASSERT_EQ(*RoundTripIntrinsicID, IntrinsicID);
+    IsFullTrip = true;
+  }
+  ASSERT_TRUE(IsFullTrip);
+}
+
+/// Check that going from VP intrinsic to equivalent non-predicated intrinsic
+/// and back results in the same intrinsic.
+TEST_F(VPIntrinsicTest, VPToNonPredIntrinsicRoundTrip) {
+  std::unique_ptr<Module> M = createVPDeclarationModule();
+  assert(M);
+
+  bool IsFullTrip = false;
+  for (const auto &VPDecl : *M) {
+    auto VPID = VPDecl.getIntrinsicID();
+    std::optional<Intrinsic::ID> NonPredID =
+        VPIntrinsic::getFunctionalIntrinsicIDForVP(VPID);
+
+    // No equivalent non-predicated intrinsic available
+    if (!NonPredID)
+      continue;
+
+    Intrinsic::ID RoundTripVPID = VPIntrinsic::getForIntrinsic(*NonPredID);
+
+    ASSERT_EQ(RoundTripVPID, VPID);
+    IsFullTrip = true;
+  }
+  ASSERT_TRUE(IsFullTrip);
+}
+
 /// Check that VPIntrinsic::getDeclarationForParams works.
 TEST_F(VPIntrinsicTest, VPIntrinsicDeclarationForParams) {
   std::unique_ptr<Module> M = createVPDeclarationModule();
