llvm-6502/include/llvm/TargetTransformInfo.h
2012-11-02 22:31:56 +00:00

205 lines
7.3 KiB
C++

//===- llvm/Transforms/TargetTransformInfo.h --------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// 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_TRANSFORMS_TARGET_TRANSFORM_INTERFACE
#define LLVM_TRANSFORMS_TARGET_TRANSFORM_INTERFACE
#include "llvm/Pass.h"
#include "llvm/AddressingMode.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Type.h"
namespace llvm {
class ScalarTargetTransformInfo;
class VectorTargetTransformInfo;
/// TargetTransformInfo - This pass provides access to the codegen
/// interfaces that are needed for IR-level transformations.
class TargetTransformInfo : public ImmutablePass {
private:
const ScalarTargetTransformInfo *STTI;
const VectorTargetTransformInfo *VTTI;
public:
/// Default ctor.
///
/// @note This has to exist, because this is a pass, but it should never be
/// used.
TargetTransformInfo();
TargetTransformInfo(const ScalarTargetTransformInfo* S,
const VectorTargetTransformInfo *V)
: ImmutablePass(ID), STTI(S), VTTI(V) {
initializeTargetTransformInfoPass(*PassRegistry::getPassRegistry());
}
TargetTransformInfo(const TargetTransformInfo &T) :
ImmutablePass(ID), STTI(T.STTI), VTTI(T.VTTI) { }
const ScalarTargetTransformInfo* getScalarTargetTransformInfo() const {
return STTI;
}
const VectorTargetTransformInfo* getVectorTargetTransformInfo() const {
return VTTI;
}
/// Pass identification, replacement for typeid.
static char ID;
};
// ---------------------------------------------------------------------------//
// The classes below are inherited and implemented by target-specific classes
// in the codegen.
// ---------------------------------------------------------------------------//
/// ScalarTargetTransformInfo - This interface is used by IR-level passes
/// that need target-dependent information for generic scalar transformations.
/// LSR, and LowerInvoke use this interface.
class ScalarTargetTransformInfo {
public:
virtual ~ScalarTargetTransformInfo() {}
/// isLegalAddImmediate - 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.
virtual bool isLegalAddImmediate(int64_t) const {
return false;
}
/// isLegalICmpImmediate - 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.
virtual bool isLegalICmpImmediate(int64_t) const {
return false;
}
/// isLegalAddressingMode - 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.
virtual bool isLegalAddressingMode(const AddrMode &AM, Type *Ty) const {
return false;
}
/// isTruncateFree - 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.
virtual bool isTruncateFree(Type *Ty1, Type *Ty2) const {
return false;
}
/// Is this type legal.
virtual bool isTypeLegal(Type *Ty) const {
return false;
}
/// getJumpBufAlignment - returns the target's jmp_buf alignment in bytes
virtual unsigned getJumpBufAlignment() const {
return 0;
}
/// getJumpBufSize - returns the target's jmp_buf size in bytes.
virtual unsigned getJumpBufSize() const {
return 0;
}
/// shouldBuildLookupTables - Return true if switches should be turned into
/// lookup tables for the target.
virtual bool shouldBuildLookupTables() const {
return true;
}
};
/// VectorTargetTransformInfo - This interface is used by the vectorizers
/// to estimate the profitability of vectorization for different instructions.
class VectorTargetTransformInfo {
public:
virtual ~VectorTargetTransformInfo() {}
/// Returns the expected cost of the instruction opcode. The opcode is one of
/// the enums like Instruction::Add. The type arguments are the type of the
/// operation.
/// Most instructions only use the first type and in that case the second
/// operand is ignored.
///
/// Exceptions:
/// * Br instructions do not use any of the types.
/// * Select instructions pass the return type as Ty1 and the selector as Ty2.
/// * Cast instructions pass the destination as Ty1 and the source as Ty2.
/// * Insert/Extract element pass only the vector type as Ty1.
/// * ShuffleVector, Load, Store do not use this call.
virtual unsigned getInstrCost(unsigned Opcode,
Type *Ty1 = 0,
Type *Ty2 = 0) const {
return 1;
}
/// Returns the expected cost of arithmetic ops, such as mul, xor, fsub, etc.
virtual unsigned getArithmeticInstrCost(unsigned Opcode, Type *Ty) const {
return 1;
}
/// Returns the cost of a vector broadcast of a scalar at place zero to a
/// vector of type 'Tp'.
virtual unsigned getBroadcastCost(Type *Tp) const {
return 1;
}
/// Returns the expected cost of cast instructions, such as bitcast, trunc,
/// zext, etc.
virtual unsigned getCastInstrCost(unsigned Opcode, Type *Dst,
Type *Src) const {
return 1;
}
/// Returns the expected cost of control-flow related instrutctions such as
/// Phi, Ret, Br.
virtual unsigned getCFInstrCost(unsigned Opcode) const {
return 1;
}
/// Returns the expected cost of compare and select instructions.
virtual unsigned getCmpSelInstrCost(unsigned Opcode, Type *ValTy,
Type *CondTy = 0) const {
return 1;
}
/// Returns the expected cost of vector Insert and Extract.
/// Use -1 to indicate that there is no information on the index value.
virtual unsigned getVectorInstrCost(unsigned Opcode, Type *Val,
unsigned Index = -1) const {
return 1;
}
/// Returns the cost of Load and Store instructions.
virtual unsigned getMemoryOpCost(unsigned Opcode, Type *Src,
unsigned Alignment,
unsigned AddressSpace) const {
return 1;
}
/// Returns the number of pieces into which the provided type must be
/// split during legalization. Zero is returned when the answer is unknown.
virtual unsigned getNumberOfParts(Type *Tp) const {
return 0;
}
};
} // End llvm namespace
#endif