mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-19 19:29:31 +00:00
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23097 91177308-0d34-0410-b5e6-96231b3b80d8
452 lines
20 KiB
C++
452 lines
20 KiB
C++
//===-- llvm/Target/TargetLowering.h - Target Lowering Info -----*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file was developed by the LLVM research group and is distributed under
|
|
// the University of Illinois Open Source License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file describes how to lower LLVM code to machine code. This has two
|
|
// main components:
|
|
//
|
|
// 1. Which ValueTypes are natively supported by the target.
|
|
// 2. Which operations are supported for supported ValueTypes.
|
|
// 3. Cost thresholds for alternative implementations of certain operations.
|
|
//
|
|
// In addition it has a few other components, like information about FP
|
|
// immediates.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_TARGET_TARGETLOWERING_H
|
|
#define LLVM_TARGET_TARGETLOWERING_H
|
|
|
|
#include "llvm/Type.h"
|
|
#include "llvm/CodeGen/ValueTypes.h"
|
|
#include <vector>
|
|
|
|
namespace llvm {
|
|
class Value;
|
|
class Function;
|
|
class TargetMachine;
|
|
class TargetData;
|
|
class TargetRegisterClass;
|
|
class SDNode;
|
|
class SDOperand;
|
|
class SelectionDAG;
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
/// TargetLowering - This class defines information used to lower LLVM code to
|
|
/// legal SelectionDAG operators that the target instruction selector can accept
|
|
/// natively.
|
|
///
|
|
/// This class also defines callbacks that targets must implement to lower
|
|
/// target-specific constructs to SelectionDAG operators.
|
|
///
|
|
class TargetLowering {
|
|
public:
|
|
/// LegalizeAction - This enum indicates whether operations are valid for a
|
|
/// target, and if not, what action should be used to make them valid.
|
|
enum LegalizeAction {
|
|
Legal, // The target natively supports this operation.
|
|
Promote, // This operation should be executed in a larger type.
|
|
Expand, // Try to expand this to other ops, otherwise use a libcall.
|
|
Custom, // Use the LowerOperation hook to implement custom lowering.
|
|
};
|
|
|
|
enum OutOfRangeShiftAmount {
|
|
Undefined, // Oversized shift amounts are undefined (default).
|
|
Mask, // Shift amounts are auto masked (anded) to value size.
|
|
Extend, // Oversized shift pulls in zeros or sign bits.
|
|
};
|
|
|
|
enum SetCCResultValue {
|
|
UndefinedSetCCResult, // SetCC returns a garbage/unknown extend.
|
|
ZeroOrOneSetCCResult, // SetCC returns a zero extended result.
|
|
ZeroOrNegativeOneSetCCResult, // SetCC returns a sign extended result.
|
|
};
|
|
|
|
TargetLowering(TargetMachine &TM);
|
|
virtual ~TargetLowering();
|
|
|
|
TargetMachine &getTargetMachine() const { return TM; }
|
|
const TargetData &getTargetData() const { return TD; }
|
|
|
|
bool isLittleEndian() const { return IsLittleEndian; }
|
|
MVT::ValueType getPointerTy() const { return PointerTy; }
|
|
MVT::ValueType getShiftAmountTy() const { return ShiftAmountTy; }
|
|
OutOfRangeShiftAmount getShiftAmountFlavor() const {return ShiftAmtHandling; }
|
|
|
|
/// isSetCCExpensive - Return true if the setcc operation is expensive for
|
|
/// this target.
|
|
bool isSetCCExpensive() const { return SetCCIsExpensive; }
|
|
|
|
/// getSetCCResultTy - Return the ValueType of the result of setcc operations.
|
|
///
|
|
MVT::ValueType getSetCCResultTy() const { return SetCCResultTy; }
|
|
|
|
/// getSetCCResultContents - For targets without boolean registers, this flag
|
|
/// returns information about the contents of the high-bits in the setcc
|
|
/// result register.
|
|
SetCCResultValue getSetCCResultContents() const { return SetCCResultContents;}
|
|
|
|
/// getRegClassFor - Return the register class that should be used for the
|
|
/// specified value type. This may only be called on legal types.
|
|
TargetRegisterClass *getRegClassFor(MVT::ValueType VT) const {
|
|
TargetRegisterClass *RC = RegClassForVT[VT];
|
|
assert(RC && "This value type is not natively supported!");
|
|
return RC;
|
|
}
|
|
|
|
/// isTypeLegal - Return true if the target has native support for the
|
|
/// specified value type. This means that it has a register that directly
|
|
/// holds it without promotions or expansions.
|
|
bool isTypeLegal(MVT::ValueType VT) const {
|
|
return RegClassForVT[VT] != 0;
|
|
}
|
|
|
|
/// getTypeAction - Return how we should legalize values of this type, either
|
|
/// it is already legal (return 'Legal') or we need to promote it to a larger
|
|
/// type (return 'Promote'), or we need to expand it into multiple registers
|
|
/// of smaller integer type (return 'Expand'). 'Custom' is not an option.
|
|
LegalizeAction getTypeAction(MVT::ValueType VT) const {
|
|
return (LegalizeAction)((ValueTypeActions >> (2*VT)) & 3);
|
|
}
|
|
unsigned getValueTypeActions() const { return ValueTypeActions; }
|
|
|
|
/// getTypeToTransformTo - For types supported by the target, this is an
|
|
/// identity function. For types that must be promoted to larger types, this
|
|
/// returns the larger type to promote to. For types that are larger than the
|
|
/// largest integer register, this contains one step in the expansion to get
|
|
/// to the smaller register.
|
|
MVT::ValueType getTypeToTransformTo(MVT::ValueType VT) const {
|
|
return TransformToType[VT];
|
|
}
|
|
|
|
typedef std::vector<double>::const_iterator legal_fpimm_iterator;
|
|
legal_fpimm_iterator legal_fpimm_begin() const {
|
|
return LegalFPImmediates.begin();
|
|
}
|
|
legal_fpimm_iterator legal_fpimm_end() const {
|
|
return LegalFPImmediates.end();
|
|
}
|
|
|
|
/// getOperationAction - Return how this operation should be treated: either
|
|
/// it is legal, needs to be promoted to a larger size, needs to be
|
|
/// expanded to some other code sequence, or the target has a custom expander
|
|
/// for it.
|
|
LegalizeAction getOperationAction(unsigned Op, MVT::ValueType VT) const {
|
|
return (LegalizeAction)((OpActions[Op] >> (2*VT)) & 3);
|
|
}
|
|
|
|
/// isOperationLegal - Return true if the specified operation is legal on this
|
|
/// target.
|
|
bool isOperationLegal(unsigned Op, MVT::ValueType VT) const {
|
|
return getOperationAction(Op, VT) == Legal;
|
|
}
|
|
|
|
/// getTypeToPromoteTo - If the action for this operation is to promote, this
|
|
/// method returns the ValueType to promote to.
|
|
MVT::ValueType getTypeToPromoteTo(unsigned Op, MVT::ValueType VT) const {
|
|
assert(getOperationAction(Op, VT) == Promote &&
|
|
"This operation isn't promoted!");
|
|
MVT::ValueType NVT = VT;
|
|
do {
|
|
NVT = (MVT::ValueType)(NVT+1);
|
|
assert(MVT::isInteger(NVT) == MVT::isInteger(VT) && NVT != MVT::isVoid &&
|
|
"Didn't find type to promote to!");
|
|
} while (!isTypeLegal(NVT) ||
|
|
getOperationAction(Op, NVT) == Promote);
|
|
return NVT;
|
|
}
|
|
|
|
/// getValueType - Return the MVT::ValueType corresponding to this LLVM type.
|
|
/// This is fixed by the LLVM operations except for the pointer size.
|
|
MVT::ValueType getValueType(const Type *Ty) const {
|
|
switch (Ty->getTypeID()) {
|
|
default: assert(0 && "Unknown type!");
|
|
case Type::VoidTyID: return MVT::isVoid;
|
|
case Type::BoolTyID: return MVT::i1;
|
|
case Type::UByteTyID:
|
|
case Type::SByteTyID: return MVT::i8;
|
|
case Type::ShortTyID:
|
|
case Type::UShortTyID: return MVT::i16;
|
|
case Type::IntTyID:
|
|
case Type::UIntTyID: return MVT::i32;
|
|
case Type::LongTyID:
|
|
case Type::ULongTyID: return MVT::i64;
|
|
case Type::FloatTyID: return MVT::f32;
|
|
case Type::DoubleTyID: return MVT::f64;
|
|
case Type::PointerTyID: return PointerTy;
|
|
}
|
|
}
|
|
|
|
/// getNumElements - Return the number of registers that this ValueType will
|
|
/// eventually require. This is always one for all non-integer types, is
|
|
/// one for any types promoted to live in larger registers, but may be more
|
|
/// than one for types (like i64) that are split into pieces.
|
|
unsigned getNumElements(MVT::ValueType VT) const {
|
|
return NumElementsForVT[VT];
|
|
}
|
|
|
|
/// This function returns the maximum number of store operations permitted
|
|
/// to replace a call to llvm.memset. The value is set by the target at the
|
|
/// performance threshold for such a replacement.
|
|
/// @brief Get maximum # of store operations permitted for llvm.memset
|
|
unsigned getMaxStoresPerMemSet() const { return maxStoresPerMemSet; }
|
|
|
|
/// This function returns the maximum number of store operations permitted
|
|
/// to replace a call to llvm.memcpy. The value is set by the target at the
|
|
/// performance threshold for such a replacement.
|
|
/// @brief Get maximum # of store operations permitted for llvm.memcpy
|
|
unsigned getMaxStoresPerMemCpy() const { return maxStoresPerMemCpy; }
|
|
|
|
/// This function returns the maximum number of store operations permitted
|
|
/// to replace a call to llvm.memmove. The value is set by the target at the
|
|
/// performance threshold for such a replacement.
|
|
/// @brief Get maximum # of store operations permitted for llvm.memmove
|
|
unsigned getMaxStoresPerMemMove() const { return maxStoresPerMemMove; }
|
|
|
|
/// This function returns true if the target allows unaligned stores. This is
|
|
/// used in situations where an array copy/move/set is converted to a sequence
|
|
/// of store operations. It ensures that such replacements don't generate
|
|
/// code that causes an alignment error (trap) on the target machine.
|
|
/// @brief Determine if the target supports unaligned stores.
|
|
bool allowsUnalignedStores() const { return allowUnalignedStores; }
|
|
|
|
//===--------------------------------------------------------------------===//
|
|
// TargetLowering Configuration Methods - These methods should be invoked by
|
|
// the derived class constructor to configure this object for the target.
|
|
//
|
|
|
|
protected:
|
|
|
|
/// setShiftAmountType - Describe the type that should be used for shift
|
|
/// amounts. This type defaults to the pointer type.
|
|
void setShiftAmountType(MVT::ValueType VT) { ShiftAmountTy = VT; }
|
|
|
|
/// setSetCCResultType - Describe the type that shoudl be used as the result
|
|
/// of a setcc operation. This defaults to the pointer type.
|
|
void setSetCCResultType(MVT::ValueType VT) { SetCCResultTy = VT; }
|
|
|
|
/// setSetCCResultContents - Specify how the target extends the result of a
|
|
/// setcc operation in a register.
|
|
void setSetCCResultContents(SetCCResultValue Ty) { SetCCResultContents = Ty; }
|
|
|
|
/// setShiftAmountFlavor - Describe how the target handles out of range shift
|
|
/// amounts.
|
|
void setShiftAmountFlavor(OutOfRangeShiftAmount OORSA) {
|
|
ShiftAmtHandling = OORSA;
|
|
}
|
|
|
|
/// setSetCCIxExpensive - This is a short term hack for targets that codegen
|
|
/// setcc as a conditional branch. This encourages the code generator to fold
|
|
/// setcc operations into other operations if possible.
|
|
void setSetCCIsExpensive() { SetCCIsExpensive = true; }
|
|
|
|
/// addRegisterClass - Add the specified register class as an available
|
|
/// regclass for the specified value type. This indicates the selector can
|
|
/// handle values of that class natively.
|
|
void addRegisterClass(MVT::ValueType VT, TargetRegisterClass *RC) {
|
|
AvailableRegClasses.push_back(std::make_pair(VT, RC));
|
|
RegClassForVT[VT] = RC;
|
|
}
|
|
|
|
/// computeRegisterProperties - Once all of the register classes are added,
|
|
/// this allows us to compute derived properties we expose.
|
|
void computeRegisterProperties();
|
|
|
|
/// setOperationAction - Indicate that the specified operation does not work
|
|
/// with the specified type and indicate what to do about it.
|
|
void setOperationAction(unsigned Op, MVT::ValueType VT,
|
|
LegalizeAction Action) {
|
|
assert(VT < 16 && Op < sizeof(OpActions)/sizeof(OpActions[0]) &&
|
|
"Table isn't big enough!");
|
|
OpActions[Op] |= Action << VT*2;
|
|
}
|
|
|
|
/// addLegalFPImmediate - Indicate that this target can instruction select
|
|
/// the specified FP immediate natively.
|
|
void addLegalFPImmediate(double Imm) {
|
|
LegalFPImmediates.push_back(Imm);
|
|
}
|
|
|
|
public:
|
|
|
|
//===--------------------------------------------------------------------===//
|
|
// Lowering methods - These methods must be implemented by targets so that
|
|
// the SelectionDAGLowering code knows how to lower these.
|
|
//
|
|
|
|
/// LowerArguments - This hook must be implemented to indicate how we should
|
|
/// lower the arguments for the specified function, into the specified DAG.
|
|
virtual std::vector<SDOperand>
|
|
LowerArguments(Function &F, SelectionDAG &DAG) = 0;
|
|
|
|
/// LowerCallTo - This hook lowers an abstract call to a function into an
|
|
/// actual call. This returns a pair of operands. The first element is the
|
|
/// return value for the function (if RetTy is not VoidTy). The second
|
|
/// element is the outgoing token chain.
|
|
typedef std::vector<std::pair<SDOperand, const Type*> > ArgListTy;
|
|
virtual std::pair<SDOperand, SDOperand>
|
|
LowerCallTo(SDOperand Chain, const Type *RetTy, bool isVarArg,
|
|
unsigned CallingConv, bool isTailCall, SDOperand Callee,
|
|
ArgListTy &Args, SelectionDAG &DAG) = 0;
|
|
|
|
/// LowerVAStart - This lowers the llvm.va_start intrinsic. If not
|
|
/// implemented, this method prints a message and aborts. This method should
|
|
/// return the modified chain value. Note that VAListPtr* correspond to the
|
|
/// llvm.va_start operand.
|
|
virtual SDOperand LowerVAStart(SDOperand Chain, SDOperand VAListP,
|
|
Value *VAListV, SelectionDAG &DAG);
|
|
|
|
/// LowerVAEnd - This lowers llvm.va_end and returns the resultant chain. If
|
|
/// not implemented, this defaults to a noop.
|
|
virtual SDOperand LowerVAEnd(SDOperand Chain, SDOperand LP, Value *LV,
|
|
SelectionDAG &DAG);
|
|
|
|
/// LowerVACopy - This lowers llvm.va_copy and returns the resultant chain.
|
|
/// If not implemented, this defaults to loading a pointer from the input and
|
|
/// storing it to the output.
|
|
virtual SDOperand LowerVACopy(SDOperand Chain, SDOperand SrcP, Value *SrcV,
|
|
SDOperand DestP, Value *DestV,
|
|
SelectionDAG &DAG);
|
|
|
|
/// LowerVAArg - This lowers the vaarg instruction. If not implemented, this
|
|
/// prints a message and aborts.
|
|
virtual std::pair<SDOperand,SDOperand>
|
|
LowerVAArg(SDOperand Chain, SDOperand VAListP, Value *VAListV,
|
|
const Type *ArgTy, SelectionDAG &DAG);
|
|
|
|
/// LowerFrameReturnAddress - This hook lowers a call to llvm.returnaddress or
|
|
/// llvm.frameaddress (depending on the value of the first argument). The
|
|
/// return values are the result pointer and the resultant token chain. If
|
|
/// not implemented, both of these intrinsics will return null.
|
|
virtual std::pair<SDOperand, SDOperand>
|
|
LowerFrameReturnAddress(bool isFrameAddr, SDOperand Chain, unsigned Depth,
|
|
SelectionDAG &DAG);
|
|
|
|
/// LowerOperation - For operations that are unsupported by the target, and
|
|
/// which are registered to use 'custom' lowering. This callback is invoked.
|
|
/// If the target has no operations that require custom lowering, it need not
|
|
/// implement this. The default implementation of this aborts.
|
|
virtual SDOperand LowerOperation(SDOperand Op, SelectionDAG &DAG);
|
|
|
|
//===--------------------------------------------------------------------===//
|
|
// Scheduler hooks
|
|
//
|
|
|
|
// InsertAtEndOfBasicBlock - This method should be implemented by targets that
|
|
// mark instructions with the 'usesCustomDAGSchedInserter' flag. These
|
|
// instructions are special in various ways, which require special support to
|
|
// insert. The specified MachineInstr is created but not inserted into any
|
|
// basic blocks, and the scheduler passes ownership of it to this method.
|
|
virtual MachineBasicBlock *InsertAtEndOfBasicBlock(MachineInstr *MI,
|
|
MachineBasicBlock *MBB);
|
|
|
|
private:
|
|
TargetMachine &TM;
|
|
const TargetData &TD;
|
|
|
|
/// IsLittleEndian - True if this is a little endian target.
|
|
///
|
|
bool IsLittleEndian;
|
|
|
|
/// PointerTy - The type to use for pointers, usually i32 or i64.
|
|
///
|
|
MVT::ValueType PointerTy;
|
|
|
|
/// ShiftAmountTy - The type to use for shift amounts, usually i8 or whatever
|
|
/// PointerTy is.
|
|
MVT::ValueType ShiftAmountTy;
|
|
|
|
OutOfRangeShiftAmount ShiftAmtHandling;
|
|
|
|
/// SetCCIsExpensive - This is a short term hack for targets that codegen
|
|
/// setcc as a conditional branch. This encourages the code generator to fold
|
|
/// setcc operations into other operations if possible.
|
|
bool SetCCIsExpensive;
|
|
|
|
/// SetCCResultTy - The type that SetCC operations use. This defaults to the
|
|
/// PointerTy.
|
|
MVT::ValueType SetCCResultTy;
|
|
|
|
/// SetCCResultContents - Information about the contents of the high-bits in
|
|
/// the result of a setcc comparison operation.
|
|
SetCCResultValue SetCCResultContents;
|
|
|
|
/// RegClassForVT - This indicates the default register class to use for
|
|
/// each ValueType the target supports natively.
|
|
TargetRegisterClass *RegClassForVT[MVT::LAST_VALUETYPE];
|
|
unsigned char NumElementsForVT[MVT::LAST_VALUETYPE];
|
|
|
|
/// ValueTypeActions - This is a bitvector that contains two bits for each
|
|
/// value type, where the two bits correspond to the LegalizeAction enum.
|
|
/// This can be queried with "getTypeAction(VT)".
|
|
unsigned ValueTypeActions;
|
|
|
|
/// TransformToType - For any value types we are promoting or expanding, this
|
|
/// contains the value type that we are changing to. For Expanded types, this
|
|
/// contains one step of the expand (e.g. i64 -> i32), even if there are
|
|
/// multiple steps required (e.g. i64 -> i16). For types natively supported
|
|
/// by the system, this holds the same type (e.g. i32 -> i32).
|
|
MVT::ValueType TransformToType[MVT::LAST_VALUETYPE];
|
|
|
|
/// OpActions - For each operation and each value type, keep a LegalizeAction
|
|
/// that indicates how instruction selection should deal with the operation.
|
|
/// Most operations are Legal (aka, supported natively by the target), but
|
|
/// operations that are not should be described. Note that operations on
|
|
/// non-legal value types are not described here.
|
|
unsigned OpActions[128];
|
|
|
|
std::vector<double> LegalFPImmediates;
|
|
|
|
std::vector<std::pair<MVT::ValueType,
|
|
TargetRegisterClass*> > AvailableRegClasses;
|
|
|
|
protected:
|
|
/// When lowering %llvm.memset this field specifies the maximum number of
|
|
/// store operations that may be substituted for the call to memset. Targets
|
|
/// must set this value based on the cost threshold for that target. Targets
|
|
/// should assume that the memset will be done using as many of the largest
|
|
/// store operations first, followed by smaller ones, if necessary, per
|
|
/// alignment restrictions. For example, storing 9 bytes on a 32-bit machine
|
|
/// with 16-bit alignment would result in four 2-byte stores and one 1-byte
|
|
/// store. This only applies to setting a constant array of a constant size.
|
|
/// @brief Specify maximum number of store instructions per memset call.
|
|
unsigned maxStoresPerMemSet;
|
|
|
|
/// When lowering %llvm.memcpy this field specifies the maximum number of
|
|
/// store operations that may be substituted for a call to memcpy. Targets
|
|
/// must set this value based on the cost threshold for that target. Targets
|
|
/// should assume that the memcpy will be done using as many of the largest
|
|
/// store operations first, followed by smaller ones, if necessary, per
|
|
/// alignment restrictions. For example, storing 7 bytes on a 32-bit machine
|
|
/// with 32-bit alignment would result in one 4-byte store, a one 2-byte store
|
|
/// and one 1-byte store. This only applies to copying a constant array of
|
|
/// constant size.
|
|
/// @brief Specify maximum bytes of store instructions per memcpy call.
|
|
unsigned maxStoresPerMemCpy;
|
|
|
|
/// When lowering %llvm.memmove this field specifies the maximum number of
|
|
/// store instructions that may be substituted for a call to memmove. Targets
|
|
/// must set this value based on the cost threshold for that target. Targets
|
|
/// should assume that the memmove will be done using as many of the largest
|
|
/// store operations first, followed by smaller ones, if necessary, per
|
|
/// alignment restrictions. For example, moving 9 bytes on a 32-bit machine
|
|
/// with 8-bit alignment would result in nine 1-byte stores. This only
|
|
/// applies to copying a constant array of constant size.
|
|
/// @brief Specify maximum bytes of store instructions per memmove call.
|
|
unsigned maxStoresPerMemMove;
|
|
|
|
/// This field specifies whether the target machine permits unaligned stores.
|
|
/// This is used to determine the size of store operations for copying
|
|
/// small arrays and other similar tasks.
|
|
/// @brief Indicate whether the target machine permits unaligned stores.
|
|
bool allowUnalignedStores;
|
|
};
|
|
} // end llvm namespace
|
|
|
|
#endif
|