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llvm-mirror/include/llvm/Analysis/TargetTransformInfo.h
Jonas Paulsson 6ae041f182 [LoopStrenghtReduce] Refactoring and addition of a new target cost function. 
Refactored so that a LSRUse owns its fixups, as oppsed to letting the
LSRInstance own them. This makes it easier to rate formulas for
LSRUses, since the fixups are available directly. The Offsets vector
has been removed since it was no longer necessary.

New target hook isFoldableMemAccessOffset(), which is used during formula
rating.

For SystemZ, this is useful to express that loads and stores with
float or vector types with a big/negative offset should be avoided in
loops. Without this, LSR will generate a lot of negative offsets that
would require extra instructions for loading the address.

Updated tests:
test/CodeGen/SystemZ/loop-01.ll

Reviewed by: Quentin Colombet and Ulrich Weigand.
https://reviews.llvm.org/D19152

llvm-svn: 278927
2016-08-17 13:24:19 +00:00

1096 lines
49 KiB
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//===- TargetTransformInfo.h ------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
/// \file
/// This pass exposes codegen information to IR-level passes. Every
/// transformation that uses codegen information is broken into three parts:
/// 1. The IR-level analysis pass.
/// 2. The IR-level transformation interface which provides the needed
/// information.
/// 3. Codegen-level implementation which uses target-specific hooks.
///
/// This file defines #2, which is the interface that IR-level transformations
/// use for querying the codegen.
///
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_TARGETTRANSFORMINFO_H
#define LLVM_ANALYSIS_TARGETTRANSFORMINFO_H
#include "llvm/ADT/Optional.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/Operator.h"
#include "llvm/IR/PassManager.h"
#include "llvm/Pass.h"
#include "llvm/Support/DataTypes.h"
#include <functional>
namespace llvm {
class Function;
class GlobalValue;
class Loop;
class Type;
class User;
class Value;
/// \brief Information about a load/store intrinsic defined by the target.
struct MemIntrinsicInfo {
MemIntrinsicInfo()
: ReadMem(false), WriteMem(false), IsSimple(false), MatchingId(0),
NumMemRefs(0), PtrVal(nullptr) {}
bool ReadMem;
bool WriteMem;
/// True only if this memory operation is non-volatile, non-atomic, and
/// unordered. (See LoadInst/StoreInst for details on each)
bool IsSimple;
// Same Id is set by the target for corresponding load/store intrinsics.
unsigned short MatchingId;
int NumMemRefs;
Value *PtrVal;
};
/// \brief This pass provides access to the codegen interfaces that are needed
/// for IR-level transformations.
class TargetTransformInfo {
public:
/// \brief Construct a TTI object using a type implementing the \c Concept
/// API below.
///
/// This is used by targets to construct a TTI wrapping their target-specific
/// implementaion that encodes appropriate costs for their target.
template <typename T> TargetTransformInfo(T Impl);
/// \brief Construct a baseline TTI object using a minimal implementation of
/// the \c Concept API below.
///
/// The TTI implementation will reflect the information in the DataLayout
/// provided if non-null.
explicit TargetTransformInfo(const DataLayout &DL);
// Provide move semantics.
TargetTransformInfo(TargetTransformInfo &&Arg);
TargetTransformInfo &operator=(TargetTransformInfo &&RHS);
// We need to define the destructor out-of-line to define our sub-classes
// out-of-line.
~TargetTransformInfo();
/// \brief Handle the invalidation of this information.
///
/// When used as a result of \c TargetIRAnalysis this method will be called
/// when the function this was computed for changes. When it returns false,
/// the information is preserved across those changes.
bool invalidate(Function &, const PreservedAnalyses &) {
// FIXME: We should probably in some way ensure that the subtarget
// information for a function hasn't changed.
return false;
}
/// \name Generic Target Information
/// @{
/// \brief Underlying constants for 'cost' values in this interface.
///
/// Many APIs in this interface return a cost. This enum defines the
/// fundamental values that should be used to interpret (and produce) those
/// costs. The costs are returned as an int rather than a member of this
/// enumeration because it is expected that the cost of one IR instruction
/// may have a multiplicative factor to it or otherwise won't fit directly
/// into the enum. Moreover, it is common to sum or average costs which works
/// better as simple integral values. Thus this enum only provides constants.
/// Also note that the returned costs are signed integers to make it natural
/// to add, subtract, and test with zero (a common boundary condition). It is
/// not expected that 2^32 is a realistic cost to be modeling at any point.
///
/// Note that these costs should usually reflect the intersection of code-size
/// cost and execution cost. A free instruction is typically one that folds
/// into another instruction. For example, reg-to-reg moves can often be
/// skipped by renaming the registers in the CPU, but they still are encoded
/// and thus wouldn't be considered 'free' here.
enum TargetCostConstants {
TCC_Free = 0, ///< Expected to fold away in lowering.
TCC_Basic = 1, ///< The cost of a typical 'add' instruction.
TCC_Expensive = 4 ///< The cost of a 'div' instruction on x86.
};
/// \brief Estimate the cost of a specific operation when lowered.
///
/// Note that this is designed to work on an arbitrary synthetic opcode, and
/// thus work for hypothetical queries before an instruction has even been
/// formed. However, this does *not* work for GEPs, and must not be called
/// for a GEP instruction. Instead, use the dedicated getGEPCost interface as
/// analyzing a GEP's cost required more information.
///
/// Typically only the result type is required, and the operand type can be
/// omitted. However, if the opcode is one of the cast instructions, the
/// operand type is required.
///
/// The returned cost is defined in terms of \c TargetCostConstants, see its
/// comments for a detailed explanation of the cost values.
int getOperationCost(unsigned Opcode, Type *Ty, Type *OpTy = nullptr) const;
/// \brief Estimate the cost of a GEP operation when lowered.
///
/// The contract for this function is the same as \c getOperationCost except
/// that it supports an interface that provides extra information specific to
/// the GEP operation.
int getGEPCost(Type *PointeeType, const Value *Ptr,
ArrayRef<const Value *> Operands) const;
/// \brief Estimate the cost of a function call when lowered.
///
/// The contract for this is the same as \c getOperationCost except that it
/// supports an interface that provides extra information specific to call
/// instructions.
///
/// This is the most basic query for estimating call cost: it only knows the
/// function type and (potentially) the number of arguments at the call site.
/// The latter is only interesting for varargs function types.
int getCallCost(FunctionType *FTy, int NumArgs = -1) const;
/// \brief Estimate the cost of calling a specific function when lowered.
///
/// This overload adds the ability to reason about the particular function
/// being called in the event it is a library call with special lowering.
int getCallCost(const Function *F, int NumArgs = -1) const;
/// \brief Estimate the cost of calling a specific function when lowered.
///
/// This overload allows specifying a set of candidate argument values.
int getCallCost(const Function *F, ArrayRef<const Value *> Arguments) const;
/// \returns A value by which our inlining threshold should be multiplied.
/// This is primarily used to bump up the inlining threshold wholesale on
/// targets where calls are unusually expensive.
///
/// TODO: This is a rather blunt instrument. Perhaps altering the costs of
/// individual classes of instructions would be better.
unsigned getInliningThresholdMultiplier() const;
/// \brief Estimate the cost of an intrinsic when lowered.
///
/// Mirrors the \c getCallCost method but uses an intrinsic identifier.
int getIntrinsicCost(Intrinsic::ID IID, Type *RetTy,
ArrayRef<Type *> ParamTys) const;
/// \brief Estimate the cost of an intrinsic when lowered.
///
/// Mirrors the \c getCallCost method but uses an intrinsic identifier.
int getIntrinsicCost(Intrinsic::ID IID, Type *RetTy,
ArrayRef<const Value *> Arguments) const;
/// \brief Estimate the cost of a given IR user when lowered.
///
/// This can estimate the cost of either a ConstantExpr or Instruction when
/// lowered. It has two primary advantages over the \c getOperationCost and
/// \c getGEPCost above, and one significant disadvantage: it can only be
/// used when the IR construct has already been formed.
///
/// The advantages are that it can inspect the SSA use graph to reason more
/// accurately about the cost. For example, all-constant-GEPs can often be
/// folded into a load or other instruction, but if they are used in some
/// other context they may not be folded. This routine can distinguish such
/// cases.
///
/// The returned cost is defined in terms of \c TargetCostConstants, see its
/// comments for a detailed explanation of the cost values.
int getUserCost(const User *U) const;
/// \brief Return true if branch divergence exists.
///
/// Branch divergence has a significantly negative impact on GPU performance
/// when threads in the same wavefront take different paths due to conditional
/// branches.
bool hasBranchDivergence() const;
/// \brief Returns whether V is a source of divergence.
///
/// This function provides the target-dependent information for
/// the target-independent DivergenceAnalysis. DivergenceAnalysis first
/// builds the dependency graph, and then runs the reachability algorithm
/// starting with the sources of divergence.
bool isSourceOfDivergence(const Value *V) const;
/// \brief Test whether calls to a function lower to actual program function
/// calls.
///
/// The idea is to test whether the program is likely to require a 'call'
/// instruction or equivalent in order to call the given function.
///
/// FIXME: It's not clear that this is a good or useful query API. Client's
/// should probably move to simpler cost metrics using the above.
/// Alternatively, we could split the cost interface into distinct code-size
/// and execution-speed costs. This would allow modelling the core of this
/// query more accurately as a call is a single small instruction, but
/// incurs significant execution cost.
bool isLoweredToCall(const Function *F) const;
/// Parameters that control the generic loop unrolling transformation.
struct UnrollingPreferences {
/// The cost threshold for the unrolled loop. Should be relative to the
/// getUserCost values returned by this API, and the expectation is that
/// the unrolled loop's instructions when run through that interface should
/// not exceed this cost. However, this is only an estimate. Also, specific
/// loops may be unrolled even with a cost above this threshold if deemed
/// profitable. Set this to UINT_MAX to disable the loop body cost
/// restriction.
unsigned Threshold;
/// If complete unrolling will reduce the cost of the loop below its
/// expected dynamic cost while rolled by this percentage, apply a discount
/// (below) to its unrolled cost.
unsigned PercentDynamicCostSavedThreshold;
/// The discount applied to the unrolled cost when the *dynamic* cost
/// savings of unrolling exceed the \c PercentDynamicCostSavedThreshold.
unsigned DynamicCostSavingsDiscount;
/// The cost threshold for the unrolled loop when optimizing for size (set
/// to UINT_MAX to disable).
unsigned OptSizeThreshold;
/// The cost threshold for the unrolled loop, like Threshold, but used
/// for partial/runtime unrolling (set to UINT_MAX to disable).
unsigned PartialThreshold;
/// The cost threshold for the unrolled loop when optimizing for size, like
/// OptSizeThreshold, but used for partial/runtime unrolling (set to
/// UINT_MAX to disable).
unsigned PartialOptSizeThreshold;
/// A forced unrolling factor (the number of concatenated bodies of the
/// original loop in the unrolled loop body). When set to 0, the unrolling
/// transformation will select an unrolling factor based on the current cost
/// threshold and other factors.
unsigned Count;
// Set the maximum unrolling factor. The unrolling factor may be selected
// using the appropriate cost threshold, but may not exceed this number
// (set to UINT_MAX to disable). This does not apply in cases where the
// loop is being fully unrolled.
unsigned MaxCount;
/// Set the maximum unrolling factor for full unrolling. Like MaxCount, but
/// applies even if full unrolling is selected. This allows a target to fall
/// back to Partial unrolling if full unrolling is above FullUnrollMaxCount.
unsigned FullUnrollMaxCount;
/// Allow partial unrolling (unrolling of loops to expand the size of the
/// loop body, not only to eliminate small constant-trip-count loops).
bool Partial;
/// Allow runtime unrolling (unrolling of loops to expand the size of the
/// loop body even when the number of loop iterations is not known at
/// compile time).
bool Runtime;
/// Allow generation of a loop remainder (extra iterations after unroll).
bool AllowRemainder;
/// Allow emitting expensive instructions (such as divisions) when computing
/// the trip count of a loop for runtime unrolling.
bool AllowExpensiveTripCount;
/// Apply loop unroll on any kind of loop
/// (mainly to loops that fail runtime unrolling).
bool Force;
};
/// \brief Get target-customized preferences for the generic loop unrolling
/// transformation. The caller will initialize UP with the current
/// target-independent defaults.
void getUnrollingPreferences(Loop *L, UnrollingPreferences &UP) const;
/// @}
/// \name Scalar Target Information
/// @{
/// \brief Flags indicating the kind of support for population count.
///
/// Compared to the SW implementation, HW support is supposed to
/// significantly boost the performance when the population is dense, and it
/// may or may not degrade performance if the population is sparse. A HW
/// support is considered as "Fast" if it can outperform, or is on a par
/// with, SW implementation when the population is sparse; otherwise, it is
/// considered as "Slow".
enum PopcntSupportKind { PSK_Software, PSK_SlowHardware, PSK_FastHardware };
/// \brief Return true if the specified immediate is legal add immediate, that
/// is the target has add instructions which can add a register with the
/// immediate without having to materialize the immediate into a register.
bool isLegalAddImmediate(int64_t Imm) const;
/// \brief Return true if the specified immediate is legal icmp immediate,
/// that is the target has icmp instructions which can compare a register
/// against the immediate without having to materialize the immediate into a
/// register.
bool isLegalICmpImmediate(int64_t Imm) const;
/// \brief Return true if the addressing mode represented by AM is legal for
/// this target, for a load/store of the specified type.
/// The type may be VoidTy, in which case only return true if the addressing
/// mode is legal for a load/store of any legal type.
/// TODO: Handle pre/postinc as well.
bool isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
bool HasBaseReg, int64_t Scale,
unsigned AddrSpace = 0) const;
/// \brief Return true if the target supports masked load/store
/// AVX2 and AVX-512 targets allow masks for consecutive load and store
bool isLegalMaskedStore(Type *DataType) const;
bool isLegalMaskedLoad(Type *DataType) const;
/// \brief Return true if the target supports masked gather/scatter
/// AVX-512 fully supports gather and scatter for vectors with 32 and 64
/// bits scalar type.
bool isLegalMaskedScatter(Type *DataType) const;
bool isLegalMaskedGather(Type *DataType) const;
/// \brief Return the cost of the scaling factor used in the addressing
/// mode represented by AM for this target, for a load/store
/// of the specified type.
/// If the AM is supported, the return value must be >= 0.
/// If the AM is not supported, it returns a negative value.
/// TODO: Handle pre/postinc as well.
int getScalingFactorCost(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
bool HasBaseReg, int64_t Scale,
unsigned AddrSpace = 0) const;
/// \brief Return true if target supports the load / store
/// instruction with the given Offset on the form reg + Offset. It
/// may be that Offset is too big for a certain type (register
/// class).
bool isFoldableMemAccessOffset(Instruction *I, int64_t Offset) const;
/// \brief Return true if it's free to truncate a value of type Ty1 to type
/// Ty2. e.g. On x86 it's free to truncate a i32 value in register EAX to i16
/// by referencing its sub-register AX.
bool isTruncateFree(Type *Ty1, Type *Ty2) const;
/// \brief Return true if it is profitable to hoist instruction in the
/// then/else to before if.
bool isProfitableToHoist(Instruction *I) const;
/// \brief Return true if this type is legal.
bool isTypeLegal(Type *Ty) const;
/// \brief Returns the target's jmp_buf alignment in bytes.
unsigned getJumpBufAlignment() const;
/// \brief Returns the target's jmp_buf size in bytes.
unsigned getJumpBufSize() const;
/// \brief Return true if switches should be turned into lookup tables for the
/// target.
bool shouldBuildLookupTables() const;
/// \brief Don't restrict interleaved unrolling to small loops.
bool enableAggressiveInterleaving(bool LoopHasReductions) const;
/// \brief Enable matching of interleaved access groups.
bool enableInterleavedAccessVectorization() const;
/// \brief Indicate that it is potentially unsafe to automatically vectorize
/// floating-point operations because the semantics of vector and scalar
/// floating-point semantics may differ. For example, ARM NEON v7 SIMD math
/// does not support IEEE-754 denormal numbers, while depending on the
/// platform, scalar floating-point math does.
/// This applies to floating-point math operations and calls, not memory
/// operations, shuffles, or casts.
bool isFPVectorizationPotentiallyUnsafe() const;
/// \brief Determine if the target supports unaligned memory accesses.
bool allowsMisalignedMemoryAccesses(LLVMContext &Context,
unsigned BitWidth, unsigned AddressSpace = 0,
unsigned Alignment = 1,
bool *Fast = nullptr) const;
/// \brief Return hardware support for population count.
PopcntSupportKind getPopcntSupport(unsigned IntTyWidthInBit) const;
/// \brief Return true if the hardware has a fast square-root instruction.
bool haveFastSqrt(Type *Ty) const;
/// \brief Return the expected cost of supporting the floating point operation
/// of the specified type.
int getFPOpCost(Type *Ty) const;
/// \brief Return the expected cost of materializing for the given integer
/// immediate of the specified type.
int getIntImmCost(const APInt &Imm, Type *Ty) const;
/// \brief Return the expected cost of materialization for the given integer
/// immediate of the specified type for a given instruction. The cost can be
/// zero if the immediate can be folded into the specified instruction.
int getIntImmCost(unsigned Opc, unsigned Idx, const APInt &Imm,
Type *Ty) const;
int getIntImmCost(Intrinsic::ID IID, unsigned Idx, const APInt &Imm,
Type *Ty) const;
/// \brief Return the expected cost for the given integer when optimising
/// for size. This is different than the other integer immediate cost
/// functions in that it is subtarget agnostic. This is useful when you e.g.
/// target one ISA such as Aarch32 but smaller encodings could be possible
/// with another such as Thumb. This return value is used as a penalty when
/// the total costs for a constant is calculated (the bigger the cost, the
/// more beneficial constant hoisting is).
int getIntImmCodeSizeCost(unsigned Opc, unsigned Idx, const APInt &Imm,
Type *Ty) const;
/// @}
/// \name Vector Target Information
/// @{
/// \brief The various kinds of shuffle patterns for vector queries.
enum ShuffleKind {
SK_Broadcast, ///< Broadcast element 0 to all other elements.
SK_Reverse, ///< Reverse the order of the vector.
SK_Alternate, ///< Choose alternate elements from vector.
SK_InsertSubvector, ///< InsertSubvector. Index indicates start offset.
SK_ExtractSubvector ///< ExtractSubvector Index indicates start offset.
};
/// \brief Additional information about an operand's possible values.
enum OperandValueKind {
OK_AnyValue, // Operand can have any value.
OK_UniformValue, // Operand is uniform (splat of a value).
OK_UniformConstantValue, // Operand is uniform constant.
OK_NonUniformConstantValue // Operand is a non uniform constant value.
};
/// \brief Additional properties of an operand's values.
enum OperandValueProperties { OP_None = 0, OP_PowerOf2 = 1 };
/// \return The number of scalar or vector registers that the target has.
/// If 'Vectors' is true, it returns the number of vector registers. If it is
/// set to false, it returns the number of scalar registers.
unsigned getNumberOfRegisters(bool Vector) const;
/// \return The width of the largest scalar or vector register type.
unsigned getRegisterBitWidth(bool Vector) const;
/// \return The bitwidth of the largest vector type that should be used to
/// load/store in the given address space.
unsigned getLoadStoreVecRegBitWidth(unsigned AddrSpace) const;
/// \return The size of a cache line in bytes.
unsigned getCacheLineSize() const;
/// \return How much before a load we should place the prefetch instruction.
/// This is currently measured in number of instructions.
unsigned getPrefetchDistance() const;
/// \return Some HW prefetchers can handle accesses up to a certain constant
/// stride. This is the minimum stride in bytes where it makes sense to start
/// adding SW prefetches. The default is 1, i.e. prefetch with any stride.
unsigned getMinPrefetchStride() const;
/// \return The maximum number of iterations to prefetch ahead. If the
/// required number of iterations is more than this number, no prefetching is
/// performed.
unsigned getMaxPrefetchIterationsAhead() const;
/// \return The maximum interleave factor that any transform should try to
/// perform for this target. This number depends on the level of parallelism
/// and the number of execution units in the CPU.
unsigned getMaxInterleaveFactor(unsigned VF) const;
/// \return The expected cost of arithmetic ops, such as mul, xor, fsub, etc.
int getArithmeticInstrCost(
unsigned Opcode, Type *Ty, OperandValueKind Opd1Info = OK_AnyValue,
OperandValueKind Opd2Info = OK_AnyValue,
OperandValueProperties Opd1PropInfo = OP_None,
OperandValueProperties Opd2PropInfo = OP_None) const;
/// \return The cost of a shuffle instruction of kind Kind and of type Tp.
/// The index and subtype parameters are used by the subvector insertion and
/// extraction shuffle kinds.
int getShuffleCost(ShuffleKind Kind, Type *Tp, int Index = 0,
Type *SubTp = nullptr) const;
/// \return The expected cost of cast instructions, such as bitcast, trunc,
/// zext, etc.
int getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src) const;
/// \return The expected cost of a sign- or zero-extended vector extract. Use
/// -1 to indicate that there is no information about the index value.
int getExtractWithExtendCost(unsigned Opcode, Type *Dst, VectorType *VecTy,
unsigned Index = -1) const;
/// \return The expected cost of control-flow related instructions such as
/// Phi, Ret, Br.
int getCFInstrCost(unsigned Opcode) const;
/// \returns The expected cost of compare and select instructions.
int getCmpSelInstrCost(unsigned Opcode, Type *ValTy,
Type *CondTy = nullptr) const;
/// \return The expected cost of vector Insert and Extract.
/// Use -1 to indicate that there is no information on the index value.
int getVectorInstrCost(unsigned Opcode, Type *Val, unsigned Index = -1) const;
/// \return The cost of Load and Store instructions.
int getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
unsigned AddressSpace) const;
/// \return The cost of masked Load and Store instructions.
int getMaskedMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
unsigned AddressSpace) const;
/// \return The cost of Gather or Scatter operation
/// \p Opcode - is a type of memory access Load or Store
/// \p DataTy - a vector type of the data to be loaded or stored
/// \p Ptr - pointer [or vector of pointers] - address[es] in memory
/// \p VariableMask - true when the memory access is predicated with a mask
/// that is not a compile-time constant
/// \p Alignment - alignment of single element
int getGatherScatterOpCost(unsigned Opcode, Type *DataTy, Value *Ptr,
bool VariableMask, unsigned Alignment) const;
/// \return The cost of the interleaved memory operation.
/// \p Opcode is the memory operation code
/// \p VecTy is the vector type of the interleaved access.
/// \p Factor is the interleave factor
/// \p Indices is the indices for interleaved load members (as interleaved
/// load allows gaps)
/// \p Alignment is the alignment of the memory operation
/// \p AddressSpace is address space of the pointer.
int getInterleavedMemoryOpCost(unsigned Opcode, Type *VecTy, unsigned Factor,
ArrayRef<unsigned> Indices, unsigned Alignment,
unsigned AddressSpace) const;
/// \brief Calculate the cost of performing a vector reduction.
///
/// This is the cost of reducing the vector value of type \p Ty to a scalar
/// value using the operation denoted by \p Opcode. The form of the reduction
/// can either be a pairwise reduction or a reduction that splits the vector
/// at every reduction level.
///
/// Pairwise:
/// (v0, v1, v2, v3)
/// ((v0+v1), (v2, v3), undef, undef)
/// Split:
/// (v0, v1, v2, v3)
/// ((v0+v2), (v1+v3), undef, undef)
int getReductionCost(unsigned Opcode, Type *Ty, bool IsPairwiseForm) const;
/// \returns The cost of Intrinsic instructions. Types analysis only.
int getIntrinsicInstrCost(Intrinsic::ID ID, Type *RetTy,
ArrayRef<Type *> Tys, FastMathFlags FMF) const;
/// \returns The cost of Intrinsic instructions. Analyses the real arguments.
int getIntrinsicInstrCost(Intrinsic::ID ID, Type *RetTy,
ArrayRef<Value *> Args, FastMathFlags FMF) const;
/// \returns The cost of Call instructions.
int getCallInstrCost(Function *F, Type *RetTy, ArrayRef<Type *> Tys) const;
/// \returns The number of pieces into which the provided type must be
/// split during legalization. Zero is returned when the answer is unknown.
unsigned getNumberOfParts(Type *Tp) const;
/// \returns The cost of the address computation. For most targets this can be
/// merged into the instruction indexing mode. Some targets might want to
/// distinguish between address computation for memory operations on vector
/// types and scalar types. Such targets should override this function.
/// The 'IsComplex' parameter is a hint that the address computation is likely
/// to involve multiple instructions and as such unlikely to be merged into
/// the address indexing mode.
int getAddressComputationCost(Type *Ty, bool IsComplex = false) const;
/// \returns The cost, if any, of keeping values of the given types alive
/// over a callsite.
///
/// Some types may require the use of register classes that do not have
/// any callee-saved registers, so would require a spill and fill.
unsigned getCostOfKeepingLiveOverCall(ArrayRef<Type *> Tys) const;
/// \returns True if the intrinsic is a supported memory intrinsic. Info
/// will contain additional information - whether the intrinsic may write
/// or read to memory, volatility and the pointer. Info is undefined
/// if false is returned.
bool getTgtMemIntrinsic(IntrinsicInst *Inst, MemIntrinsicInfo &Info) const;
/// \returns A value which is the result of the given memory intrinsic. New
/// instructions may be created to extract the result from the given intrinsic
/// memory operation. Returns nullptr if the target cannot create a result
/// from the given intrinsic.
Value *getOrCreateResultFromMemIntrinsic(IntrinsicInst *Inst,
Type *ExpectedType) const;
/// \returns True if the two functions have compatible attributes for inlining
/// purposes.
bool areInlineCompatible(const Function *Caller,
const Function *Callee) const;
/// @}
private:
/// \brief The abstract base class used to type erase specific TTI
/// implementations.
class Concept;
/// \brief The template model for the base class which wraps a concrete
/// implementation in a type erased interface.
template <typename T> class Model;
std::unique_ptr<Concept> TTIImpl;
};
class TargetTransformInfo::Concept {
public:
virtual ~Concept() = 0;
virtual const DataLayout &getDataLayout() const = 0;
virtual int getOperationCost(unsigned Opcode, Type *Ty, Type *OpTy) = 0;
virtual int getGEPCost(Type *PointeeType, const Value *Ptr,
ArrayRef<const Value *> Operands) = 0;
virtual int getCallCost(FunctionType *FTy, int NumArgs) = 0;
virtual int getCallCost(const Function *F, int NumArgs) = 0;
virtual int getCallCost(const Function *F,
ArrayRef<const Value *> Arguments) = 0;
virtual unsigned getInliningThresholdMultiplier() = 0;
virtual int getIntrinsicCost(Intrinsic::ID IID, Type *RetTy,
ArrayRef<Type *> ParamTys) = 0;
virtual int getIntrinsicCost(Intrinsic::ID IID, Type *RetTy,
ArrayRef<const Value *> Arguments) = 0;
virtual int getUserCost(const User *U) = 0;
virtual bool hasBranchDivergence() = 0;
virtual bool isSourceOfDivergence(const Value *V) = 0;
virtual bool isLoweredToCall(const Function *F) = 0;
virtual void getUnrollingPreferences(Loop *L, UnrollingPreferences &UP) = 0;
virtual bool isLegalAddImmediate(int64_t Imm) = 0;
virtual bool isLegalICmpImmediate(int64_t Imm) = 0;
virtual bool isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV,
int64_t BaseOffset, bool HasBaseReg,
int64_t Scale,
unsigned AddrSpace) = 0;
virtual bool isLegalMaskedStore(Type *DataType) = 0;
virtual bool isLegalMaskedLoad(Type *DataType) = 0;
virtual bool isLegalMaskedScatter(Type *DataType) = 0;
virtual bool isLegalMaskedGather(Type *DataType) = 0;
virtual int getScalingFactorCost(Type *Ty, GlobalValue *BaseGV,
int64_t BaseOffset, bool HasBaseReg,
int64_t Scale, unsigned AddrSpace) = 0;
virtual bool isFoldableMemAccessOffset(Instruction *I, int64_t Offset) = 0;
virtual bool isTruncateFree(Type *Ty1, Type *Ty2) = 0;
virtual bool isProfitableToHoist(Instruction *I) = 0;
virtual bool isTypeLegal(Type *Ty) = 0;
virtual unsigned getJumpBufAlignment() = 0;
virtual unsigned getJumpBufSize() = 0;
virtual bool shouldBuildLookupTables() = 0;
virtual bool enableAggressiveInterleaving(bool LoopHasReductions) = 0;
virtual bool enableInterleavedAccessVectorization() = 0;
virtual bool isFPVectorizationPotentiallyUnsafe() = 0;
virtual bool allowsMisalignedMemoryAccesses(LLVMContext &Context,
unsigned BitWidth,
unsigned AddressSpace,
unsigned Alignment,
bool *Fast) = 0;
virtual PopcntSupportKind getPopcntSupport(unsigned IntTyWidthInBit) = 0;
virtual bool haveFastSqrt(Type *Ty) = 0;
virtual int getFPOpCost(Type *Ty) = 0;
virtual int getIntImmCodeSizeCost(unsigned Opc, unsigned Idx, const APInt &Imm,
Type *Ty) = 0;
virtual int getIntImmCost(const APInt &Imm, Type *Ty) = 0;
virtual int getIntImmCost(unsigned Opc, unsigned Idx, const APInt &Imm,
Type *Ty) = 0;
virtual int getIntImmCost(Intrinsic::ID IID, unsigned Idx, const APInt &Imm,
Type *Ty) = 0;
virtual unsigned getNumberOfRegisters(bool Vector) = 0;
virtual unsigned getRegisterBitWidth(bool Vector) = 0;
virtual unsigned getLoadStoreVecRegBitWidth(unsigned AddrSpace) = 0;
virtual unsigned getCacheLineSize() = 0;
virtual unsigned getPrefetchDistance() = 0;
virtual unsigned getMinPrefetchStride() = 0;
virtual unsigned getMaxPrefetchIterationsAhead() = 0;
virtual unsigned getMaxInterleaveFactor(unsigned VF) = 0;
virtual unsigned
getArithmeticInstrCost(unsigned Opcode, Type *Ty, OperandValueKind Opd1Info,
OperandValueKind Opd2Info,
OperandValueProperties Opd1PropInfo,
OperandValueProperties Opd2PropInfo) = 0;
virtual int getShuffleCost(ShuffleKind Kind, Type *Tp, int Index,
Type *SubTp) = 0;
virtual int getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src) = 0;
virtual int getExtractWithExtendCost(unsigned Opcode, Type *Dst,
VectorType *VecTy, unsigned Index) = 0;
virtual int getCFInstrCost(unsigned Opcode) = 0;
virtual int getCmpSelInstrCost(unsigned Opcode, Type *ValTy,
Type *CondTy) = 0;
virtual int getVectorInstrCost(unsigned Opcode, Type *Val,
unsigned Index) = 0;
virtual int getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
unsigned AddressSpace) = 0;
virtual int getMaskedMemoryOpCost(unsigned Opcode, Type *Src,
unsigned Alignment,
unsigned AddressSpace) = 0;
virtual int getGatherScatterOpCost(unsigned Opcode, Type *DataTy,
Value *Ptr, bool VariableMask,
unsigned Alignment) = 0;
virtual int getInterleavedMemoryOpCost(unsigned Opcode, Type *VecTy,
unsigned Factor,
ArrayRef<unsigned> Indices,
unsigned Alignment,
unsigned AddressSpace) = 0;
virtual int getReductionCost(unsigned Opcode, Type *Ty,
bool IsPairwiseForm) = 0;
virtual int getIntrinsicInstrCost(Intrinsic::ID ID, Type *RetTy,
ArrayRef<Type *> Tys,
FastMathFlags FMF) = 0;
virtual int getIntrinsicInstrCost(Intrinsic::ID ID, Type *RetTy,
ArrayRef<Value *> Args,
FastMathFlags FMF) = 0;
virtual int getCallInstrCost(Function *F, Type *RetTy,
ArrayRef<Type *> Tys) = 0;
virtual unsigned getNumberOfParts(Type *Tp) = 0;
virtual int getAddressComputationCost(Type *Ty, bool IsComplex) = 0;
virtual unsigned getCostOfKeepingLiveOverCall(ArrayRef<Type *> Tys) = 0;
virtual bool getTgtMemIntrinsic(IntrinsicInst *Inst,
MemIntrinsicInfo &Info) = 0;
virtual Value *getOrCreateResultFromMemIntrinsic(IntrinsicInst *Inst,
Type *ExpectedType) = 0;
virtual bool areInlineCompatible(const Function *Caller,
const Function *Callee) const = 0;
};
template <typename T>
class TargetTransformInfo::Model final : public TargetTransformInfo::Concept {
T Impl;
public:
Model(T Impl) : Impl(std::move(Impl)) {}
~Model() override {}
const DataLayout &getDataLayout() const override {
return Impl.getDataLayout();
}
int getOperationCost(unsigned Opcode, Type *Ty, Type *OpTy) override {
return Impl.getOperationCost(Opcode, Ty, OpTy);
}
int getGEPCost(Type *PointeeType, const Value *Ptr,
ArrayRef<const Value *> Operands) override {
return Impl.getGEPCost(PointeeType, Ptr, Operands);
}
int getCallCost(FunctionType *FTy, int NumArgs) override {
return Impl.getCallCost(FTy, NumArgs);
}
int getCallCost(const Function *F, int NumArgs) override {
return Impl.getCallCost(F, NumArgs);
}
int getCallCost(const Function *F,
ArrayRef<const Value *> Arguments) override {
return Impl.getCallCost(F, Arguments);
}
unsigned getInliningThresholdMultiplier() override {
return Impl.getInliningThresholdMultiplier();
}
int getIntrinsicCost(Intrinsic::ID IID, Type *RetTy,
ArrayRef<Type *> ParamTys) override {
return Impl.getIntrinsicCost(IID, RetTy, ParamTys);
}
int getIntrinsicCost(Intrinsic::ID IID, Type *RetTy,
ArrayRef<const Value *> Arguments) override {
return Impl.getIntrinsicCost(IID, RetTy, Arguments);
}
int getUserCost(const User *U) override { return Impl.getUserCost(U); }
bool hasBranchDivergence() override { return Impl.hasBranchDivergence(); }
bool isSourceOfDivergence(const Value *V) override {
return Impl.isSourceOfDivergence(V);
}
bool isLoweredToCall(const Function *F) override {
return Impl.isLoweredToCall(F);
}
void getUnrollingPreferences(Loop *L, UnrollingPreferences &UP) override {
return Impl.getUnrollingPreferences(L, UP);
}
bool isLegalAddImmediate(int64_t Imm) override {
return Impl.isLegalAddImmediate(Imm);
}
bool isLegalICmpImmediate(int64_t Imm) override {
return Impl.isLegalICmpImmediate(Imm);
}
bool isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
bool HasBaseReg, int64_t Scale,
unsigned AddrSpace) override {
return Impl.isLegalAddressingMode(Ty, BaseGV, BaseOffset, HasBaseReg,
Scale, AddrSpace);
}
bool isLegalMaskedStore(Type *DataType) override {
return Impl.isLegalMaskedStore(DataType);
}
bool isLegalMaskedLoad(Type *DataType) override {
return Impl.isLegalMaskedLoad(DataType);
}
bool isLegalMaskedScatter(Type *DataType) override {
return Impl.isLegalMaskedScatter(DataType);
}
bool isLegalMaskedGather(Type *DataType) override {
return Impl.isLegalMaskedGather(DataType);
}
int getScalingFactorCost(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
bool HasBaseReg, int64_t Scale,
unsigned AddrSpace) override {
return Impl.getScalingFactorCost(Ty, BaseGV, BaseOffset, HasBaseReg,
Scale, AddrSpace);
}
bool isFoldableMemAccessOffset(Instruction *I, int64_t Offset) override {
return Impl.isFoldableMemAccessOffset(I, Offset);
}
bool isTruncateFree(Type *Ty1, Type *Ty2) override {
return Impl.isTruncateFree(Ty1, Ty2);
}
bool isProfitableToHoist(Instruction *I) override {
return Impl.isProfitableToHoist(I);
}
bool isTypeLegal(Type *Ty) override { return Impl.isTypeLegal(Ty); }
unsigned getJumpBufAlignment() override { return Impl.getJumpBufAlignment(); }
unsigned getJumpBufSize() override { return Impl.getJumpBufSize(); }
bool shouldBuildLookupTables() override {
return Impl.shouldBuildLookupTables();
}
bool enableAggressiveInterleaving(bool LoopHasReductions) override {
return Impl.enableAggressiveInterleaving(LoopHasReductions);
}
bool enableInterleavedAccessVectorization() override {
return Impl.enableInterleavedAccessVectorization();
}
bool isFPVectorizationPotentiallyUnsafe() override {
return Impl.isFPVectorizationPotentiallyUnsafe();
}
bool allowsMisalignedMemoryAccesses(LLVMContext &Context,
unsigned BitWidth, unsigned AddressSpace,
unsigned Alignment, bool *Fast) override {
return Impl.allowsMisalignedMemoryAccesses(Context, BitWidth, AddressSpace,
Alignment, Fast);
}
PopcntSupportKind getPopcntSupport(unsigned IntTyWidthInBit) override {
return Impl.getPopcntSupport(IntTyWidthInBit);
}
bool haveFastSqrt(Type *Ty) override { return Impl.haveFastSqrt(Ty); }
int getFPOpCost(Type *Ty) override { return Impl.getFPOpCost(Ty); }
int getIntImmCodeSizeCost(unsigned Opc, unsigned Idx, const APInt &Imm,
Type *Ty) override {
return Impl.getIntImmCodeSizeCost(Opc, Idx, Imm, Ty);
}
int getIntImmCost(const APInt &Imm, Type *Ty) override {
return Impl.getIntImmCost(Imm, Ty);
}
int getIntImmCost(unsigned Opc, unsigned Idx, const APInt &Imm,
Type *Ty) override {
return Impl.getIntImmCost(Opc, Idx, Imm, Ty);
}
int getIntImmCost(Intrinsic::ID IID, unsigned Idx, const APInt &Imm,
Type *Ty) override {
return Impl.getIntImmCost(IID, Idx, Imm, Ty);
}
unsigned getNumberOfRegisters(bool Vector) override {
return Impl.getNumberOfRegisters(Vector);
}
unsigned getRegisterBitWidth(bool Vector) override {
return Impl.getRegisterBitWidth(Vector);
}
unsigned getLoadStoreVecRegBitWidth(unsigned AddrSpace) override {
return Impl.getLoadStoreVecRegBitWidth(AddrSpace);
}
unsigned getCacheLineSize() override {
return Impl.getCacheLineSize();
}
unsigned getPrefetchDistance() override { return Impl.getPrefetchDistance(); }
unsigned getMinPrefetchStride() override {
return Impl.getMinPrefetchStride();
}
unsigned getMaxPrefetchIterationsAhead() override {
return Impl.getMaxPrefetchIterationsAhead();
}
unsigned getMaxInterleaveFactor(unsigned VF) override {
return Impl.getMaxInterleaveFactor(VF);
}
unsigned
getArithmeticInstrCost(unsigned Opcode, Type *Ty, OperandValueKind Opd1Info,
OperandValueKind Opd2Info,
OperandValueProperties Opd1PropInfo,
OperandValueProperties Opd2PropInfo) override {
return Impl.getArithmeticInstrCost(Opcode, Ty, Opd1Info, Opd2Info,
Opd1PropInfo, Opd2PropInfo);
}
int getShuffleCost(ShuffleKind Kind, Type *Tp, int Index,
Type *SubTp) override {
return Impl.getShuffleCost(Kind, Tp, Index, SubTp);
}
int getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src) override {
return Impl.getCastInstrCost(Opcode, Dst, Src);
}
int getExtractWithExtendCost(unsigned Opcode, Type *Dst, VectorType *VecTy,
unsigned Index) override {
return Impl.getExtractWithExtendCost(Opcode, Dst, VecTy, Index);
}
int getCFInstrCost(unsigned Opcode) override {
return Impl.getCFInstrCost(Opcode);
}
int getCmpSelInstrCost(unsigned Opcode, Type *ValTy, Type *CondTy) override {
return Impl.getCmpSelInstrCost(Opcode, ValTy, CondTy);
}
int getVectorInstrCost(unsigned Opcode, Type *Val, unsigned Index) override {
return Impl.getVectorInstrCost(Opcode, Val, Index);
}
int getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
unsigned AddressSpace) override {
return Impl.getMemoryOpCost(Opcode, Src, Alignment, AddressSpace);
}
int getMaskedMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
unsigned AddressSpace) override {
return Impl.getMaskedMemoryOpCost(Opcode, Src, Alignment, AddressSpace);
}
int getGatherScatterOpCost(unsigned Opcode, Type *DataTy,
Value *Ptr, bool VariableMask,
unsigned Alignment) override {
return Impl.getGatherScatterOpCost(Opcode, DataTy, Ptr, VariableMask,
Alignment);
}
int getInterleavedMemoryOpCost(unsigned Opcode, Type *VecTy, unsigned Factor,
ArrayRef<unsigned> Indices, unsigned Alignment,
unsigned AddressSpace) override {
return Impl.getInterleavedMemoryOpCost(Opcode, VecTy, Factor, Indices,
Alignment, AddressSpace);
}
int getReductionCost(unsigned Opcode, Type *Ty,
bool IsPairwiseForm) override {
return Impl.getReductionCost(Opcode, Ty, IsPairwiseForm);
}
int getIntrinsicInstrCost(Intrinsic::ID ID, Type *RetTy, ArrayRef<Type *> Tys,
FastMathFlags FMF) override {
return Impl.getIntrinsicInstrCost(ID, RetTy, Tys, FMF);
}
int getIntrinsicInstrCost(Intrinsic::ID ID, Type *RetTy,
ArrayRef<Value *> Args,
FastMathFlags FMF) override {
return Impl.getIntrinsicInstrCost(ID, RetTy, Args, FMF);
}
int getCallInstrCost(Function *F, Type *RetTy,
ArrayRef<Type *> Tys) override {
return Impl.getCallInstrCost(F, RetTy, Tys);
}
unsigned getNumberOfParts(Type *Tp) override {
return Impl.getNumberOfParts(Tp);
}
int getAddressComputationCost(Type *Ty, bool IsComplex) override {
return Impl.getAddressComputationCost(Ty, IsComplex);
}
unsigned getCostOfKeepingLiveOverCall(ArrayRef<Type *> Tys) override {
return Impl.getCostOfKeepingLiveOverCall(Tys);
}
bool getTgtMemIntrinsic(IntrinsicInst *Inst,
MemIntrinsicInfo &Info) override {
return Impl.getTgtMemIntrinsic(Inst, Info);
}
Value *getOrCreateResultFromMemIntrinsic(IntrinsicInst *Inst,
Type *ExpectedType) override {
return Impl.getOrCreateResultFromMemIntrinsic(Inst, ExpectedType);
}
bool areInlineCompatible(const Function *Caller,
const Function *Callee) const override {
return Impl.areInlineCompatible(Caller, Callee);
}
};
template <typename T>
TargetTransformInfo::TargetTransformInfo(T Impl)
: TTIImpl(new Model<T>(Impl)) {}
/// \brief Analysis pass providing the \c TargetTransformInfo.
///
/// The core idea of the TargetIRAnalysis is to expose an interface through
/// which LLVM targets can analyze and provide information about the middle
/// end's target-independent IR. This supports use cases such as target-aware
/// cost modeling of IR constructs.
///
/// This is a function analysis because much of the cost modeling for targets
/// is done in a subtarget specific way and LLVM supports compiling different
/// functions targeting different subtargets in order to support runtime
/// dispatch according to the observed subtarget.
class TargetIRAnalysis : public AnalysisInfoMixin<TargetIRAnalysis> {
public:
typedef TargetTransformInfo Result;
/// \brief Default construct a target IR analysis.
///
/// This will use the module's datalayout to construct a baseline
/// conservative TTI result.
TargetIRAnalysis();
/// \brief Construct an IR analysis pass around a target-provide callback.
///
/// The callback will be called with a particular function for which the TTI
/// is needed and must return a TTI object for that function.
TargetIRAnalysis(std::function<Result(const Function &)> TTICallback);
// Value semantics. We spell out the constructors for MSVC.
TargetIRAnalysis(const TargetIRAnalysis &Arg)
: TTICallback(Arg.TTICallback) {}
TargetIRAnalysis(TargetIRAnalysis &&Arg)
: TTICallback(std::move(Arg.TTICallback)) {}
TargetIRAnalysis &operator=(const TargetIRAnalysis &RHS) {
TTICallback = RHS.TTICallback;
return *this;
}
TargetIRAnalysis &operator=(TargetIRAnalysis &&RHS) {
TTICallback = std::move(RHS.TTICallback);
return *this;
}
Result run(const Function &F, FunctionAnalysisManager &);
private:
friend AnalysisInfoMixin<TargetIRAnalysis>;
static char PassID;
/// \brief The callback used to produce a result.
///
/// We use a completely opaque callback so that targets can provide whatever
/// mechanism they desire for constructing the TTI for a given function.
///
/// FIXME: Should we really use std::function? It's relatively inefficient.
/// It might be possible to arrange for even stateful callbacks to outlive
/// the analysis and thus use a function_ref which would be lighter weight.
/// This may also be less error prone as the callback is likely to reference
/// the external TargetMachine, and that reference needs to never dangle.
std::function<Result(const Function &)> TTICallback;
/// \brief Helper function used as the callback in the default constructor.
static Result getDefaultTTI(const Function &F);
};
/// \brief Wrapper pass for TargetTransformInfo.
///
/// This pass can be constructed from a TTI object which it stores internally
/// and is queried by passes.
class TargetTransformInfoWrapperPass : public ImmutablePass {
TargetIRAnalysis TIRA;
Optional<TargetTransformInfo> TTI;
virtual void anchor();
public:
static char ID;
/// \brief We must provide a default constructor for the pass but it should
/// never be used.
///
/// Use the constructor below or call one of the creation routines.
TargetTransformInfoWrapperPass();
explicit TargetTransformInfoWrapperPass(TargetIRAnalysis TIRA);
TargetTransformInfo &getTTI(const Function &F);
};
/// \brief Create an analysis pass wrapper around a TTI object.
///
/// This analysis pass just holds the TTI instance and makes it available to
/// clients.
ImmutablePass *createTargetTransformInfoWrapperPass(TargetIRAnalysis TIRA);
} // End llvm namespace
#endif
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