llvm-6502/include/llvm/CodeGen/SelectionDAG.h
2003-11-11 22:41:34 +00:00

371 lines
13 KiB
C++

//===-- llvm/CodeGen/SelectionDAG.h - InstSelection DAG Rep. ----*- 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 declares the SelectionDAG class, which is used to represent an LLVM
// function in a low-level representation suitable for instruction selection.
// This DAG is constructed as the first step of instruction selection in order
// to allow implementation of machine specific optimizations and code
// simplifications.
//
// The representation used by the SelectionDAG is a target-independent
// representation, which is loosly modeled after the GCC RTL representation, but
// is significantly simpler.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_SELECTIONDAG_H
#define LLVM_CODEGEN_SELECTIONDAG_H
#include "llvm/CodeGen/ValueTypes.h"
#include "Support/DataTypes.h"
#include <map>
#include <vector>
#include <cassert>
namespace llvm {
class Value;
class Type;
class Instruction;
class CallInst;
class BasicBlock;
class MachineBasicBlock;
class MachineFunction;
class TargetMachine;
class SelectionDAGNode;
class SelectionDAGBlock;
class SelectionDAGBuilder;
class SelectionDAGTargetBuilder;
/// ISD namespace - This namespace contains an enum which represents all of the
/// SelectionDAG node types and value types.
///
namespace ISD {
enum NodeType {
// ChainNode nodes are used to sequence operations within a basic block
// which cannot be reordered (such as loads, stores, calls, etc).
// BlockChainNodes are used to connect the DAG's for different basic blocks
// into one big DAG.
ChainNode, BlockChainNode,
// ProtoNodes are nodes that are only half way constructed.
ProtoNode,
// Leaf nodes
Constant, FrameIndex, BasicBlock,
// Simple binary arithmetic operators
Plus, Minus, Times, SDiv, UDiv, SRem, URem,
// Bitwise operators
And, Or, Xor,
// Comparisons
SetEQ, SetNE, SetLT, SetLE, SetGT, SetGE,
// Control flow instructions
Br, BrCond, Switch, Ret, RetVoid,
// Other operators
Load, Store, PHI, Call,
// Unknown operators, of a specified arity
Unspec1, Unspec2
};
}
class SelectionDAG {
friend class SelectionDAGBuilder;
MachineFunction &F;
const TargetMachine &TM;
MVT::ValueType PointerType; // The ValueType the target uses for pointers
// ValueMap - The SelectionDAGNode for each LLVM value in the function.
std::map<const Value*, SelectionDAGNode*> ValueMap;
// BlockMap - The MachineBasicBlock created for each LLVM BasicBlock
std::map<const BasicBlock*, MachineBasicBlock*> BlockMap;
// Root - The root of the entire DAG
SelectionDAGNode *Root;
// AllNodes - All of the nodes in the DAG
std::vector<SelectionDAGNode*> AllNodes;
public:
/// SelectionDAG constructor - Build a SelectionDAG for the specified
/// function. Implemented in DAGBuilder.cpp
///
SelectionDAG(MachineFunction &F, const TargetMachine &TM,
SelectionDAGTargetBuilder &SDTB);
~SelectionDAG();
/// getValueType - Return the ValueType for the specified LLVM type. This
/// method works on all scalar LLVM types.
///
MVT::ValueType getValueType(const Type *Ty) const;
/// getRoot - Return the root of the current SelectionDAG.
///
SelectionDAGNode *getRoot() const { return Root; }
/// getMachineFunction - Return the MachineFunction object that this
/// SelectionDAG corresponds to.
///
MachineFunction &getMachineFunction() const { return F; }
//===--------------------------------------------------------------------===//
// Addition and updating methods
//
/// addNode - Add the specified node to the SelectionDAG so that it will be
/// deleted when the DAG is...
///
SelectionDAGNode *addNode(SelectionDAGNode *N) {
AllNodes.push_back(N);
return N;
}
/// addNodeForValue - Add the specified node to the SelectionDAG so that it
/// will be deleted when the DAG is... and update the value map to indicate
/// that the specified DAG node computes the value. Note that it is an error
/// to specify multiple DAG nodes that compute the same value.
///
SelectionDAGNode *addNodeForValue(SelectionDAGNode *N, const Value *V) {
assert(ValueMap.count(V) == 0 && "Value already has a DAG node!");
return addNode(ValueMap[V] = N);
}
void dump() const;
private:
void addInstructionToDAG(const Instruction &I, const BasicBlock &BB);
};
/// SelectionDAGReducedValue - During the reducer pass we need the ability to
/// add an arbitrary (but usually 1 or 0) number of arbitrarily sized values to
/// the selection DAG. Because of this, we represent these values as a singly
/// linked list of values attached to the DAGNode. We end up putting the
/// arbitrary state for the value in subclasses of this node.
///
/// Note that this class does not have a virtual dtor, this is because we know
/// that the subclasses will not hold state that needs to be destroyed.
///
class SelectionDAGReducedValue {
unsigned Code;
SelectionDAGReducedValue *Next;
public:
SelectionDAGReducedValue(unsigned C) : Code(C), Next(0) {}
/// getValueCode - Return the code for this reducer value...
///
unsigned getValueCode() const { return Code; }
/// getNext - Return the next value in the list
///
const SelectionDAGReducedValue *getNext() const { return Next; }
void setNext(SelectionDAGReducedValue *N) { Next = N; }
SelectionDAGReducedValue *getNext() { return Next; }
};
/// SelectionDAGNode - Represents one node in the selection DAG.
///
class SelectionDAGNode {
std::vector<SelectionDAGNode*> Uses;
ISD::NodeType NodeType;
MVT::ValueType ValueType;
MachineBasicBlock *BB;
SelectionDAGReducedValue *ValList;
/// Costs - Each pair of elements of 'Costs' contains the cost of producing
/// the value with the target specific slot number and the production number
/// to use to produce it. A zero value for the production number indicates
/// that the cost has not yet been computed.
unsigned *Costs;
public:
SelectionDAGNode(ISD::NodeType NT, MVT::ValueType VT,
MachineBasicBlock *bb = 0)
: NodeType(NT), ValueType(VT), BB(bb), ValList(0), Costs(0) {}
SelectionDAGNode(ISD::NodeType NT, MVT::ValueType VT, MachineBasicBlock *bb,
SelectionDAGNode *N)
: NodeType(NT), ValueType(VT), BB(bb), ValList(0), Costs(0) {
assert(NT != ISD::ProtoNode && "Cannot specify uses for a protonode!");
Uses.reserve(1); Uses.push_back(N);
}
SelectionDAGNode(ISD::NodeType NT, MVT::ValueType VT, MachineBasicBlock *bb,
SelectionDAGNode *N1, SelectionDAGNode *N2)
: NodeType(NT), ValueType(VT), BB(bb), ValList(0), Costs(0) {
assert(NT != ISD::ProtoNode && "Cannot specify uses for a protonode!");
Uses.reserve(2); Uses.push_back(N1); Uses.push_back(N2);
}
SelectionDAGNode(ISD::NodeType NT, MVT::ValueType VT, MachineBasicBlock *bb,
SelectionDAGNode *N1, SelectionDAGNode *N2,
SelectionDAGNode *N3)
: NodeType(NT), ValueType(VT), BB(bb), ValList(0), Costs(0) {
assert(NT != ISD::ProtoNode && "Cannot specify uses for a protonode!");
Uses.reserve(3); Uses.push_back(N1); Uses.push_back(N2); Uses.push_back(N3);
}
~SelectionDAGNode() { delete [] Costs; delete ValList; }
void setNode(ISD::NodeType NT, MachineBasicBlock *bb) {
assert(NodeType == ISD::ProtoNode && NT != ISD::ProtoNode);
NodeType = NT; BB = bb;
}
void setNode(ISD::NodeType NT, MachineBasicBlock *bb, SelectionDAGNode *N) {
assert(NodeType == ISD::ProtoNode && NT != ISD::ProtoNode);
NodeType = NT; BB = bb; Uses.reserve(1); Uses.push_back(N);
}
void setNode(ISD::NodeType NT, MachineBasicBlock *bb,
SelectionDAGNode *N1, SelectionDAGNode *N2) {
assert(NodeType == ISD::ProtoNode && NT != ISD::ProtoNode);
NodeType = NT; BB = bb;
Uses.reserve(1); Uses.push_back(N1); Uses.push_back(N2);
}
//===--------------------------------------------------------------------===//
// Accessors
//
ISD::NodeType getNodeType() const { return NodeType; }
MVT::ValueType getValueType() const { return ValueType; }
MachineBasicBlock *getBB() const { return BB; }
SelectionDAGNode *getUse(unsigned Num) {
assert(Num < Uses.size() && "Invalid child # of SelectionDAGNode!");
return Uses[Num];
}
template<class Type>
Type *getValue(unsigned Code) const {
SelectionDAGReducedValue *Vals = ValList;
while (1) {
assert(Vals && "Code does not exist in this list!");
if (Vals->getValueCode() == Code)
return (Type*)Vals;
Vals = Vals->getNext();
}
}
template<class Type>
Type *hasValue(unsigned Code) const {
SelectionDAGReducedValue *Vals = ValList;
while (Vals) {
if (Vals->getValueCode() == Code)
return (Type*)Vals;
Vals = Vals->getNext();
}
return false;
}
void addValue(SelectionDAGReducedValue *New) {
assert(New->getNext() == 0);
New->setNext(ValList);
ValList = New;
}
//===--------------------------------------------------------------------===//
// Utility methods used by the pattern matching instruction selector
//
/// getPatternFor - Return the pattern selected to compute the specified slot,
/// or zero if there is no pattern yet.
///
unsigned getPatternFor(unsigned Slot) const {
return Costs ? Costs[Slot*2] : 0;
}
/// getCostFor - Return the cost to compute the value corresponding to Slot.
///
unsigned getCostFor(unsigned Slot) const {
return Costs ? Costs[Slot*2+1] : 0;
}
/// setPatternCostFor - Sets the pattern and the cost for the specified slot
/// to the specified values. This allocates the Costs vector if necessary, so
/// you must specify the maximum number of slots that may be used.
///
void setPatternCostFor(unsigned Slot, unsigned Pattern, unsigned Cost,
unsigned NumSlots) {
if (Costs == 0) {
Costs = new unsigned[NumSlots*2];
for (unsigned i = 0; i != NumSlots*2; ++i) Costs[i] = 0;
}
Costs[Slot*2] = Pattern;
Costs[Slot*2+1] = Cost;
}
void dump() const;
private:
void printit(unsigned Offset, unsigned &LastID,
std::map<const SelectionDAGNode*, unsigned> &NodeIDs) const;
};
/// SelectionDAGTargetBuilder - This class must be implemented by the target, to
/// indicate how to perform the extremely target-specific tasks of building DAG
/// nodes to represent the calling convention used by the target.
///
struct SelectionDAGTargetBuilder {
/// expandArguments - This method is called once by the SelectionDAG
/// construction mechanisms to add DAG nodes for each formal argument to the
/// current function. If any of the incoming arguments lives on the stack,
/// this method should also create the stack slots for the arguments as
/// necessary.
virtual void expandArguments(SelectionDAG &SD) = 0;
/// expandCall - This method is called once per function call by the
/// SelectionDAG construction algorithm. It must add DAG nodes to the
/// SelectionDAG specified to perform that call.
virtual void expandCall(SelectionDAG &SD, CallInst &CI) = 0;
};
namespace ISD {
enum { // Builtin Slot numbers
Constant_i1_Slot,
Constant_i8_Slot,
Constant_i16_Slot,
Constant_i32_Slot,
Constant_i64_Slot,
Constant_f32_Slot,
Constant_f64_Slot,
FrameIndex_i32_Slot,
FrameIndex_i64_Slot,
BasicBlock_i32_Slot,
BasicBlock_i64_Slot,
NumBuiltinSlots
};
}
template<typename ValType, unsigned NodeCode>
struct ReducedValue : public SelectionDAGReducedValue {
ReducedValue(const ValType &V) : SelectionDAGReducedValue(NodeCode), Val(V) {}
ValType Val;
};
typedef ReducedValue<int, ISD::FrameIndex_i32_Slot > ReducedValue_FrameIndex_i32;
typedef ReducedValue<int, ISD::FrameIndex_i64_Slot > ReducedValue_FrameIndex_i64;
typedef ReducedValue<MachineBasicBlock*, ISD::BasicBlock_i32_Slot > ReducedValue_BasicBlock_i32;
typedef ReducedValue<MachineBasicBlock*, ISD::BasicBlock_i64_Slot > ReducedValue_BasicBlock_i64;
typedef ReducedValue<bool , ISD::Constant_i1_Slot > ReducedValue_Constant_i1;
typedef ReducedValue<unsigned char , ISD::Constant_i8_Slot > ReducedValue_Constant_i8;
typedef ReducedValue<unsigned short, ISD::Constant_i16_Slot> ReducedValue_Constant_i16;
typedef ReducedValue<unsigned , ISD::Constant_i32_Slot> ReducedValue_Constant_i32;
typedef ReducedValue<uint64_t , ISD::Constant_i64_Slot> ReducedValue_Constant_i64;
typedef ReducedValue<float , ISD::Constant_f32_Slot> ReducedValue_Constant_f32;
typedef ReducedValue<double , ISD::Constant_f64_Slot> ReducedValue_Constant_f64;
} // End llvm namespace
#endif