///
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "basictti"
#include "llvm/CodeGen/Passes.h"
+#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/Support/CommandLine.h"
#include "llvm/Target/TargetLowering.h"
+#include "llvm/Target/TargetSubtargetInfo.h"
#include <utility>
-
using namespace llvm;
+static cl::opt<unsigned>
+PartialUnrollingThreshold("partial-unrolling-threshold", cl::init(0),
+ cl::desc("Threshold for partial unrolling"), cl::Hidden);
+
+#define DEBUG_TYPE "basictti"
+
namespace {
-class BasicTTI : public ImmutablePass, public TargetTransformInfo {
- const TargetLoweringBase *TLI;
+class BasicTTI final : public ImmutablePass, public TargetTransformInfo {
+ const TargetMachine *TM;
/// Estimate the overhead of scalarizing an instruction. Insert and Extract
/// are set if the result needs to be inserted and/or extracted from vectors.
unsigned getScalarizationOverhead(Type *Ty, bool Insert, bool Extract) const;
+ /// Estimate the cost overhead of SK_Alternate shuffle.
+ unsigned getAltShuffleOverhead(Type *Ty) const;
+
+ const TargetLoweringBase *getTLI() const {
+ return TM->getSubtargetImpl()->getTargetLowering();
+ }
+
public:
- BasicTTI() : ImmutablePass(ID), TLI(0) {
+ BasicTTI() : ImmutablePass(ID), TM(nullptr) {
llvm_unreachable("This pass cannot be directly constructed");
}
- BasicTTI(const TargetLoweringBase *TLI) : ImmutablePass(ID), TLI(TLI) {
+ BasicTTI(const TargetMachine *TM) : ImmutablePass(ID), TM(TM) {
initializeBasicTTIPass(*PassRegistry::getPassRegistry());
}
- virtual void initializePass() {
+ void initializePass() override {
pushTTIStack(this);
}
- virtual void finalizePass() {
- popTTIStack();
- }
-
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
TargetTransformInfo::getAnalysisUsage(AU);
}
static char ID;
/// Provide necessary pointer adjustments for the two base classes.
- virtual void *getAdjustedAnalysisPointer(const void *ID) {
+ void *getAdjustedAnalysisPointer(const void *ID) override {
if (ID == &TargetTransformInfo::ID)
return (TargetTransformInfo*)this;
return this;
}
+ bool hasBranchDivergence() const override;
+
/// \name Scalar TTI Implementations
/// @{
- virtual bool isLegalAddImmediate(int64_t imm) const;
- virtual bool isLegalICmpImmediate(int64_t imm) const;
- virtual bool isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV,
- int64_t BaseOffset, bool HasBaseReg,
- int64_t Scale) const;
- virtual bool isTruncateFree(Type *Ty1, Type *Ty2) const;
- virtual bool isTypeLegal(Type *Ty) const;
- virtual unsigned getJumpBufAlignment() const;
- virtual unsigned getJumpBufSize() const;
- virtual bool shouldBuildLookupTables() const;
+ bool isLegalAddImmediate(int64_t imm) const override;
+ bool isLegalICmpImmediate(int64_t imm) const override;
+ bool isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV,
+ int64_t BaseOffset, bool HasBaseReg,
+ int64_t Scale) const override;
+ int getScalingFactorCost(Type *Ty, GlobalValue *BaseGV,
+ int64_t BaseOffset, bool HasBaseReg,
+ int64_t Scale) const override;
+ bool isTruncateFree(Type *Ty1, Type *Ty2) const override;
+ bool isTypeLegal(Type *Ty) const override;
+ unsigned getJumpBufAlignment() const override;
+ unsigned getJumpBufSize() const override;
+ bool shouldBuildLookupTables() const override;
+ bool haveFastSqrt(Type *Ty) const override;
+ void getUnrollingPreferences(Loop *L,
+ UnrollingPreferences &UP) const override;
/// @}
/// \name Vector TTI Implementations
/// @{
- virtual unsigned getNumberOfRegisters(bool Vector) const;
- virtual unsigned getMaximumUnrollFactor() const;
- virtual unsigned getRegisterBitWidth(bool Vector) const;
- virtual unsigned getArithmeticInstrCost(unsigned Opcode, Type *Ty) const;
- virtual unsigned getShuffleCost(ShuffleKind Kind, Type *Tp,
- int Index, Type *SubTp) const;
- virtual unsigned getCastInstrCost(unsigned Opcode, Type *Dst,
- Type *Src) const;
- virtual unsigned getCFInstrCost(unsigned Opcode) const;
- virtual unsigned getCmpSelInstrCost(unsigned Opcode, Type *ValTy,
- Type *CondTy) const;
- virtual unsigned getVectorInstrCost(unsigned Opcode, Type *Val,
- unsigned Index) const;
- virtual unsigned getMemoryOpCost(unsigned Opcode, Type *Src,
- unsigned Alignment,
- unsigned AddressSpace) const;
- virtual unsigned getIntrinsicInstrCost(Intrinsic::ID, Type *RetTy,
- ArrayRef<Type*> Tys) const;
- virtual unsigned getNumberOfParts(Type *Tp) const;
- virtual unsigned getAddressComputationCost(Type *Ty) const;
+ unsigned getNumberOfRegisters(bool Vector) const override;
+ unsigned getMaximumUnrollFactor() const override;
+ unsigned getRegisterBitWidth(bool Vector) const override;
+ unsigned getArithmeticInstrCost(unsigned Opcode, Type *Ty, OperandValueKind,
+ OperandValueKind) const override;
+ unsigned getShuffleCost(ShuffleKind Kind, Type *Tp,
+ int Index, Type *SubTp) const override;
+ unsigned getCastInstrCost(unsigned Opcode, Type *Dst,
+ Type *Src) const override;
+ unsigned getCFInstrCost(unsigned Opcode) const override;
+ unsigned getCmpSelInstrCost(unsigned Opcode, Type *ValTy,
+ Type *CondTy) const override;
+ unsigned getVectorInstrCost(unsigned Opcode, Type *Val,
+ unsigned Index) const override;
+ unsigned getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
+ unsigned AddressSpace) const override;
+ unsigned getIntrinsicInstrCost(Intrinsic::ID, Type *RetTy,
+ ArrayRef<Type*> Tys) const override;
+ unsigned getNumberOfParts(Type *Tp) const override;
+ unsigned getAddressComputationCost( Type *Ty, bool IsComplex) const override;
+ unsigned getReductionCost(unsigned Opcode, Type *Ty,
+ bool IsPairwise) const override;
/// @}
};
char BasicTTI::ID = 0;
ImmutablePass *
-llvm::createBasicTargetTransformInfoPass(const TargetLoweringBase *TLI) {
- return new BasicTTI(TLI);
+llvm::createBasicTargetTransformInfoPass(const TargetMachine *TM) {
+ return new BasicTTI(TM);
}
+bool BasicTTI::hasBranchDivergence() const { return false; }
bool BasicTTI::isLegalAddImmediate(int64_t imm) const {
- return TLI->isLegalAddImmediate(imm);
+ return getTLI()->isLegalAddImmediate(imm);
}
bool BasicTTI::isLegalICmpImmediate(int64_t imm) const {
- return TLI->isLegalICmpImmediate(imm);
+ return getTLI()->isLegalICmpImmediate(imm);
}
bool BasicTTI::isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV,
AM.BaseOffs = BaseOffset;
AM.HasBaseReg = HasBaseReg;
AM.Scale = Scale;
- return TLI->isLegalAddressingMode(AM, Ty);
+ return getTLI()->isLegalAddressingMode(AM, Ty);
+}
+
+int BasicTTI::getScalingFactorCost(Type *Ty, GlobalValue *BaseGV,
+ int64_t BaseOffset, bool HasBaseReg,
+ int64_t Scale) const {
+ TargetLoweringBase::AddrMode AM;
+ AM.BaseGV = BaseGV;
+ AM.BaseOffs = BaseOffset;
+ AM.HasBaseReg = HasBaseReg;
+ AM.Scale = Scale;
+ return getTLI()->getScalingFactorCost(AM, Ty);
}
bool BasicTTI::isTruncateFree(Type *Ty1, Type *Ty2) const {
- return TLI->isTruncateFree(Ty1, Ty2);
+ return getTLI()->isTruncateFree(Ty1, Ty2);
}
bool BasicTTI::isTypeLegal(Type *Ty) const {
- EVT T = TLI->getValueType(Ty);
- return TLI->isTypeLegal(T);
+ EVT T = getTLI()->getValueType(Ty);
+ return getTLI()->isTypeLegal(T);
}
unsigned BasicTTI::getJumpBufAlignment() const {
- return TLI->getJumpBufAlignment();
+ return getTLI()->getJumpBufAlignment();
}
unsigned BasicTTI::getJumpBufSize() const {
- return TLI->getJumpBufSize();
+ return getTLI()->getJumpBufSize();
}
bool BasicTTI::shouldBuildLookupTables() const {
- return TLI->supportJumpTables() &&
- (TLI->isOperationLegalOrCustom(ISD::BR_JT, MVT::Other) ||
- TLI->isOperationLegalOrCustom(ISD::BRIND, MVT::Other));
+ const TargetLoweringBase *TLI = getTLI();
+ return TLI->isOperationLegalOrCustom(ISD::BR_JT, MVT::Other) ||
+ TLI->isOperationLegalOrCustom(ISD::BRIND, MVT::Other);
+}
+
+bool BasicTTI::haveFastSqrt(Type *Ty) const {
+ const TargetLoweringBase *TLI = getTLI();
+ EVT VT = TLI->getValueType(Ty);
+ return TLI->isTypeLegal(VT) && TLI->isOperationLegalOrCustom(ISD::FSQRT, VT);
+}
+
+void BasicTTI::getUnrollingPreferences(Loop *L,
+ UnrollingPreferences &UP) const {
+ // This unrolling functionality is target independent, but to provide some
+ // motivation for its intended use, for x86:
+
+ // According to the Intel 64 and IA-32 Architectures Optimization Reference
+ // Manual, Intel Core models and later have a loop stream detector
+ // (and associated uop queue) that can benefit from partial unrolling.
+ // The relevant requirements are:
+ // - The loop must have no more than 4 (8 for Nehalem and later) branches
+ // taken, and none of them may be calls.
+ // - The loop can have no more than 18 (28 for Nehalem and later) uops.
+
+ // According to the Software Optimization Guide for AMD Family 15h Processors,
+ // models 30h-4fh (Steamroller and later) have a loop predictor and loop
+ // buffer which can benefit from partial unrolling.
+ // The relevant requirements are:
+ // - The loop must have fewer than 16 branches
+ // - The loop must have less than 40 uops in all executed loop branches
+
+ // The number of taken branches in a loop is hard to estimate here, and
+ // benchmarking has revealed that it is better not to be conservative when
+ // estimating the branch count. As a result, we'll ignore the branch limits
+ // until someone finds a case where it matters in practice.
+
+ unsigned MaxOps;
+ const TargetSubtargetInfo *ST = &TM->getSubtarget<TargetSubtargetInfo>();
+ if (PartialUnrollingThreshold.getNumOccurrences() > 0)
+ MaxOps = PartialUnrollingThreshold;
+ else if (ST->getSchedModel()->LoopMicroOpBufferSize > 0)
+ MaxOps = ST->getSchedModel()->LoopMicroOpBufferSize;
+ else
+ return;
+
+ // Scan the loop: don't unroll loops with calls.
+ for (Loop::block_iterator I = L->block_begin(), E = L->block_end();
+ I != E; ++I) {
+ BasicBlock *BB = *I;
+
+ for (BasicBlock::iterator J = BB->begin(), JE = BB->end(); J != JE; ++J)
+ if (isa<CallInst>(J) || isa<InvokeInst>(J)) {
+ ImmutableCallSite CS(J);
+ if (const Function *F = CS.getCalledFunction()) {
+ if (!TopTTI->isLoweredToCall(F))
+ continue;
+ }
+
+ return;
+ }
+ }
+
+ // Enable runtime and partial unrolling up to the specified size.
+ UP.Partial = UP.Runtime = true;
+ UP.PartialThreshold = UP.PartialOptSizeThreshold = MaxOps;
}
//===----------------------------------------------------------------------===//
return 1;
}
-unsigned BasicTTI::getArithmeticInstrCost(unsigned Opcode, Type *Ty) const {
+unsigned BasicTTI::getArithmeticInstrCost(unsigned Opcode, Type *Ty,
+ OperandValueKind,
+ OperandValueKind) const {
// Check if any of the operands are vector operands.
+ const TargetLoweringBase *TLI = getTLI();
int ISD = TLI->InstructionOpcodeToISD(Opcode);
assert(ISD && "Invalid opcode");
std::pair<unsigned, MVT> LT = TLI->getTypeLegalizationCost(Ty);
+ bool IsFloat = Ty->getScalarType()->isFloatingPointTy();
+ // Assume that floating point arithmetic operations cost twice as much as
+ // integer operations.
+ unsigned OpCost = (IsFloat ? 2 : 1);
+
if (TLI->isOperationLegalOrPromote(ISD, LT.second)) {
// The operation is legal. Assume it costs 1.
- // If the type is split to multiple registers, assume that thre is some
+ // If the type is split to multiple registers, assume that there is some
// overhead to this.
// TODO: Once we have extract/insert subvector cost we need to use them.
if (LT.first > 1)
- return LT.first * 2;
- return LT.first * 1;
+ return LT.first * 2 * OpCost;
+ return LT.first * 1 * OpCost;
}
if (!TLI->isOperationExpand(ISD, LT.second)) {
// If the operation is custom lowered then assume
// thare the code is twice as expensive.
- return LT.first * 2;
+ return LT.first * 2 * OpCost;
}
// Else, assume that we need to scalarize this op.
}
// We don't know anything about this scalar instruction.
- return 1;
+ return OpCost;
+}
+
+unsigned BasicTTI::getAltShuffleOverhead(Type *Ty) const {
+ assert(Ty->isVectorTy() && "Can only shuffle vectors");
+ unsigned Cost = 0;
+ // Shuffle cost is equal to the cost of extracting element from its argument
+ // plus the cost of inserting them onto the result vector.
+
+ // e.g. <4 x float> has a mask of <0,5,2,7> i.e we need to extract from index
+ // 0 of first vector, index 1 of second vector,index 2 of first vector and
+ // finally index 3 of second vector and insert them at index <0,1,2,3> of
+ // result vector.
+ for (int i = 0, e = Ty->getVectorNumElements(); i < e; ++i) {
+ Cost += TopTTI->getVectorInstrCost(Instruction::InsertElement, Ty, i);
+ Cost += TopTTI->getVectorInstrCost(Instruction::ExtractElement, Ty, i);
+ }
+ return Cost;
}
unsigned BasicTTI::getShuffleCost(ShuffleKind Kind, Type *Tp, int Index,
Type *SubTp) const {
+ if (Kind == SK_Alternate) {
+ return getAltShuffleOverhead(Tp);
+ }
return 1;
}
unsigned BasicTTI::getCastInstrCost(unsigned Opcode, Type *Dst,
Type *Src) const {
+ const TargetLoweringBase *TLI = getTLI();
int ISD = TLI->InstructionOpcodeToISD(Opcode);
assert(ISD && "Invalid opcode");
return 0;
// If the cast is marked as legal (or promote) then assume low cost.
- if (TLI->isOperationLegalOrPromote(ISD, DstLT.second))
+ if (SrcLT.first == DstLT.first &&
+ TLI->isOperationLegalOrPromote(ISD, DstLT.second))
return 1;
// Handle scalar conversions.
unsigned BasicTTI::getCmpSelInstrCost(unsigned Opcode, Type *ValTy,
Type *CondTy) const {
+ const TargetLoweringBase *TLI = getTLI();
int ISD = TLI->InstructionOpcodeToISD(Opcode);
assert(ISD && "Invalid opcode");
unsigned BasicTTI::getVectorInstrCost(unsigned Opcode, Type *Val,
unsigned Index) const {
- return 1;
+ std::pair<unsigned, MVT> LT = getTLI()->getTypeLegalizationCost(Val->getScalarType());
+
+ return LT.first;
}
unsigned BasicTTI::getMemoryOpCost(unsigned Opcode, Type *Src,
unsigned Alignment,
unsigned AddressSpace) const {
assert(!Src->isVoidTy() && "Invalid type");
- std::pair<unsigned, MVT> LT = TLI->getTypeLegalizationCost(Src);
+ std::pair<unsigned, MVT> LT = getTLI()->getTypeLegalizationCost(Src);
+
+ // Assuming that all loads of legal types cost 1.
+ unsigned Cost = LT.first;
+
+ if (Src->isVectorTy() &&
+ Src->getPrimitiveSizeInBits() < LT.second.getSizeInBits()) {
+ // This is a vector load that legalizes to a larger type than the vector
+ // itself. Unless the corresponding extending load or truncating store is
+ // legal, then this will scalarize.
+ TargetLowering::LegalizeAction LA = TargetLowering::Expand;
+ EVT MemVT = getTLI()->getValueType(Src, true);
+ if (MemVT.isSimple() && MemVT != MVT::Other) {
+ if (Opcode == Instruction::Store)
+ LA = getTLI()->getTruncStoreAction(LT.second, MemVT.getSimpleVT());
+ else
+ LA = getTLI()->getLoadExtAction(ISD::EXTLOAD, MemVT.getSimpleVT());
+ }
- // Assume that all loads of legal types cost 1.
- return LT.first;
+ if (LA != TargetLowering::Legal && LA != TargetLowering::Custom) {
+ // This is a vector load/store for some illegal type that is scalarized.
+ // We must account for the cost of building or decomposing the vector.
+ Cost += getScalarizationOverhead(Src, Opcode != Instruction::Store,
+ Opcode == Instruction::Store);
+ }
+ }
+
+ return Cost;
}
-unsigned BasicTTI::getIntrinsicInstrCost(Intrinsic::ID, Type *RetTy,
+unsigned BasicTTI::getIntrinsicInstrCost(Intrinsic::ID IID, Type *RetTy,
ArrayRef<Type *> Tys) const {
- // assume that we need to scalarize this intrinsic.
- unsigned ScalarizationCost = 0;
- unsigned ScalarCalls = 1;
- if (RetTy->isVectorTy()) {
- ScalarizationCost = getScalarizationOverhead(RetTy, true, false);
- ScalarCalls = std::max(ScalarCalls, RetTy->getVectorNumElements());
- }
- for (unsigned i = 0, ie = Tys.size(); i != ie; ++i) {
- if (Tys[i]->isVectorTy()) {
- ScalarizationCost += getScalarizationOverhead(Tys[i], false, true);
+ unsigned ISD = 0;
+ switch (IID) {
+ default: {
+ // Assume that we need to scalarize this intrinsic.
+ unsigned ScalarizationCost = 0;
+ unsigned ScalarCalls = 1;
+ if (RetTy->isVectorTy()) {
+ ScalarizationCost = getScalarizationOverhead(RetTy, true, false);
ScalarCalls = std::max(ScalarCalls, RetTy->getVectorNumElements());
}
+ for (unsigned i = 0, ie = Tys.size(); i != ie; ++i) {
+ if (Tys[i]->isVectorTy()) {
+ ScalarizationCost += getScalarizationOverhead(Tys[i], false, true);
+ ScalarCalls = std::max(ScalarCalls, RetTy->getVectorNumElements());
+ }
+ }
+
+ return ScalarCalls + ScalarizationCost;
+ }
+ // Look for intrinsics that can be lowered directly or turned into a scalar
+ // intrinsic call.
+ case Intrinsic::sqrt: ISD = ISD::FSQRT; break;
+ case Intrinsic::sin: ISD = ISD::FSIN; break;
+ case Intrinsic::cos: ISD = ISD::FCOS; break;
+ case Intrinsic::exp: ISD = ISD::FEXP; break;
+ case Intrinsic::exp2: ISD = ISD::FEXP2; break;
+ case Intrinsic::log: ISD = ISD::FLOG; break;
+ case Intrinsic::log10: ISD = ISD::FLOG10; break;
+ case Intrinsic::log2: ISD = ISD::FLOG2; break;
+ case Intrinsic::fabs: ISD = ISD::FABS; break;
+ case Intrinsic::copysign: ISD = ISD::FCOPYSIGN; break;
+ case Intrinsic::floor: ISD = ISD::FFLOOR; break;
+ case Intrinsic::ceil: ISD = ISD::FCEIL; break;
+ case Intrinsic::trunc: ISD = ISD::FTRUNC; break;
+ case Intrinsic::nearbyint:
+ ISD = ISD::FNEARBYINT; break;
+ case Intrinsic::rint: ISD = ISD::FRINT; break;
+ case Intrinsic::round: ISD = ISD::FROUND; break;
+ case Intrinsic::pow: ISD = ISD::FPOW; break;
+ case Intrinsic::fma: ISD = ISD::FMA; break;
+ case Intrinsic::fmuladd: ISD = ISD::FMA; break;
+ // FIXME: We should return 0 whenever getIntrinsicCost == TCC_Free.
+ case Intrinsic::lifetime_start:
+ case Intrinsic::lifetime_end:
+ return 0;
+ }
+
+ const TargetLoweringBase *TLI = getTLI();
+ std::pair<unsigned, MVT> LT = TLI->getTypeLegalizationCost(RetTy);
+
+ if (TLI->isOperationLegalOrPromote(ISD, LT.second)) {
+ // The operation is legal. Assume it costs 1.
+ // If the type is split to multiple registers, assume that thre is some
+ // overhead to this.
+ // TODO: Once we have extract/insert subvector cost we need to use them.
+ if (LT.first > 1)
+ return LT.first * 2;
+ return LT.first * 1;
+ }
+
+ if (!TLI->isOperationExpand(ISD, LT.second)) {
+ // If the operation is custom lowered then assume
+ // thare the code is twice as expensive.
+ return LT.first * 2;
+ }
+
+ // If we can't lower fmuladd into an FMA estimate the cost as a floating
+ // point mul followed by an add.
+ if (IID == Intrinsic::fmuladd)
+ return TopTTI->getArithmeticInstrCost(BinaryOperator::FMul, RetTy) +
+ TopTTI->getArithmeticInstrCost(BinaryOperator::FAdd, RetTy);
+
+ // Else, assume that we need to scalarize this intrinsic. For math builtins
+ // this will emit a costly libcall, adding call overhead and spills. Make it
+ // very expensive.
+ if (RetTy->isVectorTy()) {
+ unsigned Num = RetTy->getVectorNumElements();
+ unsigned Cost = TopTTI->getIntrinsicInstrCost(IID, RetTy->getScalarType(),
+ Tys);
+ return 10 * Cost * Num;
}
- return ScalarCalls + ScalarizationCost;
+
+ // This is going to be turned into a library call, make it expensive.
+ return 10;
}
unsigned BasicTTI::getNumberOfParts(Type *Tp) const {
- std::pair<unsigned, MVT> LT = TLI->getTypeLegalizationCost(Tp);
+ std::pair<unsigned, MVT> LT = getTLI()->getTypeLegalizationCost(Tp);
return LT.first;
}
-unsigned BasicTTI::getAddressComputationCost(Type *Ty) const {
+unsigned BasicTTI::getAddressComputationCost(Type *Ty, bool IsComplex) const {
return 0;
}
+
+unsigned BasicTTI::getReductionCost(unsigned Opcode, Type *Ty,
+ bool IsPairwise) const {
+ assert(Ty->isVectorTy() && "Expect a vector type");
+ unsigned NumVecElts = Ty->getVectorNumElements();
+ unsigned NumReduxLevels = Log2_32(NumVecElts);
+ unsigned ArithCost = NumReduxLevels *
+ TopTTI->getArithmeticInstrCost(Opcode, Ty);
+ // Assume the pairwise shuffles add a cost.
+ unsigned ShuffleCost =
+ NumReduxLevels * (IsPairwise + 1) *
+ TopTTI->getShuffleCost(SK_ExtractSubvector, Ty, NumVecElts / 2, Ty);
+ return ShuffleCost + ArithCost + getScalarizationOverhead(Ty, false, true);
+}