[RISCV] Add basic code modeling for llvm.experimental.stepvector intrinsic

[liaolucy]

Summary

Scalable vectors llvm.experimental.stepvector intrinsic
will crash due to an invalid cost when run the code through the loopunroll.

[kito-cheng]

The cost model might not the best, but that prevent crash due to invalid cost, I believe we can keep improve that later.

[liaolucy]

Thanks Kito. Rebase

llvm/lib/Target/RISCV/RISCVTargetTransformInfo.h

public:
   }
 
   InstructionCost getSpliceCost(VectorType *Tp, int Index);
   InstructionCost getShuffleCost(TTI::ShuffleKind Kind, VectorType *Tp,
                                  ArrayRef<int> Mask, int Index,
                                  VectorType *SubTp,
                                  ArrayRef<Value *> Args = None);
 
+  InstructionCost getIntrinsicInstrCost(const IntrinsicCostAttributes &ICA,
+                                        TTI::TargetCostKind CostKind);
+
   InstructionCost getGatherScatterOpCost(unsigned Opcode, Type *DataTy,
                                          const Value *Ptr, bool VariableMask,
                                          Align Alignment,
                                          TTI::TargetCostKind CostKind,
                                          const Instruction *I);
 
   InstructionCost getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src,
                                    TTI::CastContextHint CCH,

llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp

InstructionCost RISCVTTIImpl::getGatherScatterOpCost(
 
   auto *VTy = cast<FixedVectorType>(DataTy);
   unsigned NumLoads = VTy->getNumElements();
   InstructionCost MemOpCost =
       getMemoryOpCost(Opcode, VTy->getElementType(), Alignment, 0, CostKind, I);
   return NumLoads * MemOpCost;
 }
 
+InstructionCost
+RISCVTTIImpl::getIntrinsicInstrCost(const IntrinsicCostAttributes &ICA,
+                                    TTI::TargetCostKind CostKind) {
+  auto *RetTy = ICA.getReturnType();
+  switch (ICA.getID()) {
+  // TODO: add more intrinsic
+  case Intrinsic::experimental_stepvector: {
+    unsigned Cost = 1; // vid
+    auto LT = TLI->getTypeLegalizationCost(DL, RetTy);
+    return Cost + (LT.first - 1);
+  }
+  default:
+    break;
+  }
+  return BaseT::getIntrinsicInstrCost(ICA, CostKind);
+}
+
 InstructionCost RISCVTTIImpl::getCastInstrCost(unsigned Opcode, Type *Dst,
                                                Type *Src,
                                                TTI::CastContextHint CCH,
                                                TTI::TargetCostKind CostKind,
                                                const Instruction *I) {
   if (isa<VectorType>(Dst) && isa<VectorType>(Src)) {
     // FIXME: Need to compute legalizing cost for illegal types.
     if (!isTypeLegal(Src) || !isTypeLegal(Dst))

llvm/test/Analysis/CostModel/RISCV/stepvector.ll

+; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py
+; Check stepvector for scalable vector
+; RUN: opt < %s -passes='print<cost-model>' 2>&1 -disable-output -S -mtriple=riscv64 -mattr=+v | FileCheck %s
+
+define void @stepvector() {
+; CHECK-LABEL: 'stepvector'
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %zero = call <vscale x 1 x i8> @llvm.experimental.stepvector.nxv1i8()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %1 = call <vscale x 2 x i8> @llvm.experimental.stepvector.nxv2i8()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %2 = call <vscale x 4 x i8> @llvm.experimental.stepvector.nxv4i8()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %3 = call <vscale x 8 x i8> @llvm.experimental.stepvector.nxv8i8()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %4 = call <vscale x 8 x i8> @llvm.experimental.stepvector.nxv8i8()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %5 = call <vscale x 8 x i8> @llvm.experimental.stepvector.nxv8i8()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %6 = call <vscale x 8 x i8> @llvm.experimental.stepvector.nxv8i8()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %7 = call <vscale x 8 x i8> @llvm.experimental.stepvector.nxv8i8()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %8 = call <vscale x 16 x i8> @llvm.experimental.stepvector.nxv16i8()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %9 = call <vscale x 32 x i8> @llvm.experimental.stepvector.nxv32i8()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %10 = call <vscale x 64 x i8> @llvm.experimental.stepvector.nxv64i8()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %11 = call <vscale x 1 x i16> @llvm.experimental.stepvector.nxv1i16()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %12 = call <vscale x 2 x i16> @llvm.experimental.stepvector.nxv2i16()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %13 = call <vscale x 4 x i16> @llvm.experimental.stepvector.nxv4i16()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %14 = call <vscale x 8 x i16> @llvm.experimental.stepvector.nxv8i16()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %15 = call <vscale x 16 x i16> @llvm.experimental.stepvector.nxv16i16()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %16 = call <vscale x 16 x i16> @llvm.experimental.stepvector.nxv16i16()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %17 = call <vscale x 16 x i16> @llvm.experimental.stepvector.nxv16i16()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %18 = call <vscale x 16 x i16> @llvm.experimental.stepvector.nxv16i16()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %19 = call <vscale x 16 x i16> @llvm.experimental.stepvector.nxv16i16()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %20 = call <vscale x 32 x i16> @llvm.experimental.stepvector.nxv32i16()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %21 = call <vscale x 1 x i32> @llvm.experimental.stepvector.nxv1i32()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %22 = call <vscale x 2 x i32> @llvm.experimental.stepvector.nxv2i32()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %23 = call <vscale x 4 x i32> @llvm.experimental.stepvector.nxv4i32()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %24 = call <vscale x 8 x i32> @llvm.experimental.stepvector.nxv8i32()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %25 = call <vscale x 16 x i32> @llvm.experimental.stepvector.nxv16i32()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %26 = call <vscale x 16 x i32> @llvm.experimental.stepvector.nxv16i32()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %27 = call <vscale x 16 x i32> @llvm.experimental.stepvector.nxv16i32()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %28 = call <vscale x 16 x i32> @llvm.experimental.stepvector.nxv16i32()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %29 = call <vscale x 16 x i32> @llvm.experimental.stepvector.nxv16i32()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %30 = call <vscale x 1 x i64> @llvm.experimental.stepvector.nxv1i64()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %31 = call <vscale x 2 x i64> @llvm.experimental.stepvector.nxv2i64()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %32 = call <vscale x 4 x i64> @llvm.experimental.stepvector.nxv4i64()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %33 = call <vscale x 8 x i64> @llvm.experimental.stepvector.nxv8i64()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %34 = call <vscale x 8 x i64> @llvm.experimental.stepvector.nxv8i64()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %35 = call <vscale x 8 x i64> @llvm.experimental.stepvector.nxv8i64()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %36 = call <vscale x 8 x i64> @llvm.experimental.stepvector.nxv8i64()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %37 = call <vscale x 8 x i64> @llvm.experimental.stepvector.nxv8i64()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %38 = call <vscale x 8 x i64> @llvm.experimental.stepvector.nxv8i64()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %39 = call <vscale x 16 x i64> @llvm.experimental.stepvector.nxv16i64()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %40 = call <vscale x 16 x i64> @llvm.experimental.stepvector.nxv16i64()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %41 = call <vscale x 16 x i64> @llvm.experimental.stepvector.nxv16i64()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %42 = call <vscale x 16 x i64> @llvm.experimental.stepvector.nxv16i64()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %43 = call <vscale x 16 x i64> @llvm.experimental.stepvector.nxv16i64()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %44 = call <vscale x 16 x i64> @llvm.experimental.stepvector.nxv16i64()
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret void
+;
+  %zero = call <vscale x 1 x i8> @llvm.experimental.stepvector.nxv1i8()
+  %1 = call <vscale x 2 x i8> @llvm.experimental.stepvector.nxv2i8()
+  %2 = call <vscale x 4 x i8> @llvm.experimental.stepvector.nxv4i8()
+  %3 = call <vscale x 8 x i8> @llvm.experimental.stepvector.nxv8i8()
+  %4 = call <vscale x 8 x i8> @llvm.experimental.stepvector.nxv8i8()
+  %5 = call <vscale x 8 x i8> @llvm.experimental.stepvector.nxv8i8()
+  %6 = call <vscale x 8 x i8> @llvm.experimental.stepvector.nxv8i8()
+  %7 = call <vscale x 8 x i8> @llvm.experimental.stepvector.nxv8i8()
+  %8 = call <vscale x 16 x i8> @llvm.experimental.stepvector.nxv16i8()
+  %9 = call <vscale x 32 x i8> @llvm.experimental.stepvector.nxv32i8()
+  %10 = call <vscale x 64 x i8> @llvm.experimental.stepvector.nxv64i8()
+  %11 = call <vscale x 1 x i16> @llvm.experimental.stepvector.nxv1i16()
+  %12 = call <vscale x 2 x i16> @llvm.experimental.stepvector.nxv2i16()
+  %13 = call <vscale x 4 x i16> @llvm.experimental.stepvector.nxv4i16()
+  %14 = call <vscale x 8 x i16> @llvm.experimental.stepvector.nxv8i16()
+  %15 = call <vscale x 16 x i16> @llvm.experimental.stepvector.nxv16i16()
+  %16 = call <vscale x 16 x i16> @llvm.experimental.stepvector.nxv16i16()
+  %17 = call <vscale x 16 x i16> @llvm.experimental.stepvector.nxv16i16()
+  %18 = call <vscale x 16 x i16> @llvm.experimental.stepvector.nxv16i16()
+  %19 = call <vscale x 16 x i16> @llvm.experimental.stepvector.nxv16i16()
+  %20 = call <vscale x 32 x i16> @llvm.experimental.stepvector.nxv32i16()
+  %21 = call <vscale x 1 x i32> @llvm.experimental.stepvector.nxv1i32()
+  %22 = call <vscale x 2 x i32> @llvm.experimental.stepvector.nxv2i32()
+  %23 = call <vscale x 4 x i32> @llvm.experimental.stepvector.nxv4i32()
+  %24 = call <vscale x 8 x i32> @llvm.experimental.stepvector.nxv8i32()
+  %25 = call <vscale x 16 x i32> @llvm.experimental.stepvector.nxv16i32()
+  %26 = call <vscale x 16 x i32> @llvm.experimental.stepvector.nxv16i32()
+  %27 = call <vscale x 16 x i32> @llvm.experimental.stepvector.nxv16i32()
+  %28 = call <vscale x 16 x i32> @llvm.experimental.stepvector.nxv16i32()
+  %29 = call <vscale x 16 x i32> @llvm.experimental.stepvector.nxv16i32()
+  %30 = call <vscale x 1 x i64> @llvm.experimental.stepvector.nxv1i64()
+  %31 = call <vscale x 2 x i64> @llvm.experimental.stepvector.nxv2i64()
+  %32 = call <vscale x 4 x i64> @llvm.experimental.stepvector.nxv4i64()
+  %33 = call <vscale x 8 x i64> @llvm.experimental.stepvector.nxv8i64()
+  %34 = call <vscale x 8 x i64> @llvm.experimental.stepvector.nxv8i64()
+  %35 = call <vscale x 8 x i64> @llvm.experimental.stepvector.nxv8i64()
+  %36 = call <vscale x 8 x i64> @llvm.experimental.stepvector.nxv8i64()
+  %37 = call <vscale x 8 x i64> @llvm.experimental.stepvector.nxv8i64()
+  %38 = call <vscale x 8 x i64> @llvm.experimental.stepvector.nxv8i64()
+  %39 = call <vscale x 16 x i64> @llvm.experimental.stepvector.nxv16i64()
+  %40 = call <vscale x 16 x i64> @llvm.experimental.stepvector.nxv16i64()
+  %41 = call <vscale x 16 x i64> @llvm.experimental.stepvector.nxv16i64()
+  %42 = call <vscale x 16 x i64> @llvm.experimental.stepvector.nxv16i64()
+  %43 = call <vscale x 16 x i64> @llvm.experimental.stepvector.nxv16i64()
+  %44 = call <vscale x 16 x i64> @llvm.experimental.stepvector.nxv16i64()
+  ret void
+}
+
+
+declare <vscale x 1 x i8> @llvm.experimental.stepvector.nxv1i8()
+declare <vscale x 2 x i8> @llvm.experimental.stepvector.nxv2i8()
+declare <vscale x 4 x i8> @llvm.experimental.stepvector.nxv4i8()
+declare <vscale x 8 x i8> @llvm.experimental.stepvector.nxv8i8()
+declare <vscale x 16 x i8> @llvm.experimental.stepvector.nxv16i8()
+declare <vscale x 32 x i8> @llvm.experimental.stepvector.nxv32i8()
+declare <vscale x 64 x i8> @llvm.experimental.stepvector.nxv64i8()
+declare <vscale x 1 x i16> @llvm.experimental.stepvector.nxv1i16()
+declare <vscale x 2 x i16> @llvm.experimental.stepvector.nxv2i16()
+declare <vscale x 4 x i16> @llvm.experimental.stepvector.nxv4i16()
+declare <vscale x 8 x i16> @llvm.experimental.stepvector.nxv8i16()
+declare <vscale x 16 x i16> @llvm.experimental.stepvector.nxv16i16()
+declare <vscale x 32 x i16> @llvm.experimental.stepvector.nxv32i16()
+declare <vscale x 1 x i32> @llvm.experimental.stepvector.nxv1i32()
+declare <vscale x 2 x i32> @llvm.experimental.stepvector.nxv2i32()
+declare <vscale x 4 x i32> @llvm.experimental.stepvector.nxv4i32()
+declare <vscale x 8 x i32> @llvm.experimental.stepvector.nxv8i32()
+declare <vscale x 16 x i32> @llvm.experimental.stepvector.nxv16i32()
+declare <vscale x 1 x i64> @llvm.experimental.stepvector.nxv1i64()
+declare <vscale x 2 x i64> @llvm.experimental.stepvector.nxv2i64()
+declare <vscale x 4 x i64> @llvm.experimental.stepvector.nxv4i64()
+declare <vscale x 8 x i64> @llvm.experimental.stepvector.nxv8i64()
+declare <vscale x 16 x i64> @llvm.experimental.stepvector.nxv16i64()