llvm-6502/include/llvm/CodeGen/SelectionDAG.h
2006-10-05 22:57:11 +00:00

485 lines
21 KiB
C++

//===-- llvm/CodeGen/SelectionDAG.h - InstSelection DAG ---------*- 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, and transitively defines the
// SDNode class and subclasses.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_SELECTIONDAG_H
#define LLVM_CODEGEN_SELECTIONDAG_H
#include "llvm/CodeGen/SelectionDAGCSEMap.h"
#include "llvm/ADT/ilist"
#include <list>
#include <vector>
#include <map>
#include <set>
#include <string>
namespace llvm {
class TargetLowering;
class TargetMachine;
class MachineDebugInfo;
class MachineFunction;
class MachineConstantPoolValue;
/// SelectionDAG class - This is used to represent a portion of an LLVM function
/// in a low-level Data Dependence DAG 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 has some similarities to the GCC RTL representation,
/// but is significantly more simple, powerful, and is a graph form instead of a
/// linear form.
///
class SelectionDAG {
TargetLowering &TLI;
MachineFunction &MF;
MachineDebugInfo *DI;
/// Root - The root of the entire DAG. EntryNode - The starting token.
SDOperand Root, EntryNode;
/// AllNodes - A linked list of nodes in the current DAG.
ilist<SDNode> AllNodes;
/// CSEMap - This structure is used to memoize nodes, automatically performing
/// CSE with existing nodes with a duplicate is requested.
SelectionDAGCSEMap CSEMap;
public:
SelectionDAG(TargetLowering &tli, MachineFunction &mf, MachineDebugInfo *di)
: TLI(tli), MF(mf), DI(di) {
EntryNode = Root = getNode(ISD::EntryToken, MVT::Other);
}
~SelectionDAG();
MachineFunction &getMachineFunction() const { return MF; }
const TargetMachine &getTarget() const;
TargetLowering &getTargetLoweringInfo() const { return TLI; }
MachineDebugInfo *getMachineDebugInfo() const { return DI; }
/// viewGraph - Pop up a GraphViz/gv window with the DAG rendered using 'dot'.
///
void viewGraph();
#ifndef NDEBUG
std::map<const SDNode *, std::string> NodeGraphAttrs;
#endif
/// clearGraphAttrs - Clear all previously defined node graph attributes.
/// Intended to be used from a debugging tool (eg. gdb).
void clearGraphAttrs();
/// setGraphAttrs - Set graph attributes for a node. (eg. "color=red".)
///
void setGraphAttrs(const SDNode *N, const char *Attrs);
/// getGraphAttrs - Get graph attributes for a node. (eg. "color=red".)
/// Used from getNodeAttributes.
const std::string getGraphAttrs(const SDNode *N) const;
/// setGraphColor - Convenience for setting node color attribute.
///
void setGraphColor(const SDNode *N, const char *Color);
typedef ilist<SDNode>::const_iterator allnodes_const_iterator;
allnodes_const_iterator allnodes_begin() const { return AllNodes.begin(); }
allnodes_const_iterator allnodes_end() const { return AllNodes.end(); }
typedef ilist<SDNode>::iterator allnodes_iterator;
allnodes_iterator allnodes_begin() { return AllNodes.begin(); }
allnodes_iterator allnodes_end() { return AllNodes.end(); }
/// getRoot - Return the root tag of the SelectionDAG.
///
const SDOperand &getRoot() const { return Root; }
/// getEntryNode - Return the token chain corresponding to the entry of the
/// function.
const SDOperand &getEntryNode() const { return EntryNode; }
/// setRoot - Set the current root tag of the SelectionDAG.
///
const SDOperand &setRoot(SDOperand N) { return Root = N; }
/// Combine - This iterates over the nodes in the SelectionDAG, folding
/// certain types of nodes together, or eliminating superfluous nodes. When
/// the AfterLegalize argument is set to 'true', Combine takes care not to
/// generate any nodes that will be illegal on the target.
void Combine(bool AfterLegalize);
/// Legalize - This transforms the SelectionDAG into a SelectionDAG that is
/// compatible with the target instruction selector, as indicated by the
/// TargetLowering object.
///
/// Note that this is an involved process that may invalidate pointers into
/// the graph.
void Legalize();
/// RemoveDeadNodes - This method deletes all unreachable nodes in the
/// SelectionDAG.
void RemoveDeadNodes();
/// getVTList - Return an SDVTList that represents the list of values
/// specified.
SDVTList getVTList(MVT::ValueType VT);
SDVTList getVTList(MVT::ValueType VT1, MVT::ValueType VT2);
SDVTList getVTList(MVT::ValueType VT1, MVT::ValueType VT2,MVT::ValueType VT3);
SDVTList getVTList(const MVT::ValueType *VTs, unsigned NumVTs);
/// getNodeValueTypes - These are obsolete, use getVTList instead.
const MVT::ValueType *getNodeValueTypes(MVT::ValueType VT) {
return getVTList(VT).VTs;
}
const MVT::ValueType *getNodeValueTypes(MVT::ValueType VT1,
MVT::ValueType VT2) {
return getVTList(VT1, VT2).VTs;
}
const MVT::ValueType *getNodeValueTypes(MVT::ValueType VT1,MVT::ValueType VT2,
MVT::ValueType VT3) {
return getVTList(VT1, VT2, VT3).VTs;
}
const MVT::ValueType *getNodeValueTypes(std::vector<MVT::ValueType> &VTList) {
return getVTList(&VTList[0], VTList.size()).VTs;
}
//===--------------------------------------------------------------------===//
// Node creation methods.
//
SDOperand getString(const std::string &Val);
SDOperand getConstant(uint64_t Val, MVT::ValueType VT, bool isTarget = false);
SDOperand getTargetConstant(uint64_t Val, MVT::ValueType VT) {
return getConstant(Val, VT, true);
}
SDOperand getConstantFP(double Val, MVT::ValueType VT, bool isTarget = false);
SDOperand getTargetConstantFP(double Val, MVT::ValueType VT) {
return getConstantFP(Val, VT, true);
}
SDOperand getGlobalAddress(const GlobalValue *GV, MVT::ValueType VT,
int offset = 0, bool isTargetGA = false);
SDOperand getTargetGlobalAddress(const GlobalValue *GV, MVT::ValueType VT,
int offset = 0) {
return getGlobalAddress(GV, VT, offset, true);
}
SDOperand getFrameIndex(int FI, MVT::ValueType VT, bool isTarget = false);
SDOperand getTargetFrameIndex(int FI, MVT::ValueType VT) {
return getFrameIndex(FI, VT, true);
}
SDOperand getJumpTable(int JTI, MVT::ValueType VT, bool isTarget = false);
SDOperand getTargetJumpTable(int JTI, MVT::ValueType VT) {
return getJumpTable(JTI, VT, true);
}
SDOperand getConstantPool(Constant *C, MVT::ValueType VT,
unsigned Align = 0, int Offs = 0, bool isT=false);
SDOperand getTargetConstantPool(Constant *C, MVT::ValueType VT,
unsigned Align = 0, int Offset = 0) {
return getConstantPool(C, VT, Align, Offset, true);
}
SDOperand getConstantPool(MachineConstantPoolValue *C, MVT::ValueType VT,
unsigned Align = 0, int Offs = 0, bool isT=false);
SDOperand getTargetConstantPool(MachineConstantPoolValue *C,
MVT::ValueType VT, unsigned Align = 0,
int Offset = 0) {
return getConstantPool(C, VT, Align, Offset, true);
}
SDOperand getBasicBlock(MachineBasicBlock *MBB);
SDOperand getExternalSymbol(const char *Sym, MVT::ValueType VT);
SDOperand getTargetExternalSymbol(const char *Sym, MVT::ValueType VT);
SDOperand getValueType(MVT::ValueType);
SDOperand getRegister(unsigned Reg, MVT::ValueType VT);
SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N) {
return getNode(ISD::CopyToReg, MVT::Other, Chain,
getRegister(Reg, N.getValueType()), N);
}
// This version of the getCopyToReg method takes an extra operand, which
// indicates that there is potentially an incoming flag value (if Flag is not
// null) and that there should be a flag result.
SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N,
SDOperand Flag) {
const MVT::ValueType *VTs = getNodeValueTypes(MVT::Other, MVT::Flag);
SDOperand Ops[] = { Chain, getRegister(Reg, N.getValueType()), N, Flag };
return getNode(ISD::CopyToReg, VTs, 2, Ops, Flag.Val ? 4 : 3);
}
// Similar to last getCopyToReg() except parameter Reg is a SDOperand
SDOperand getCopyToReg(SDOperand Chain, SDOperand Reg, SDOperand N,
SDOperand Flag) {
const MVT::ValueType *VTs = getNodeValueTypes(MVT::Other, MVT::Flag);
SDOperand Ops[] = { Chain, Reg, N, Flag };
return getNode(ISD::CopyToReg, VTs, 2, Ops, Flag.Val ? 4 : 3);
}
SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT::ValueType VT) {
const MVT::ValueType *VTs = getNodeValueTypes(VT, MVT::Other);
SDOperand Ops[] = { Chain, getRegister(Reg, VT) };
return getNode(ISD::CopyFromReg, VTs, 2, Ops, 2);
}
// This version of the getCopyFromReg method takes an extra operand, which
// indicates that there is potentially an incoming flag value (if Flag is not
// null) and that there should be a flag result.
SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT::ValueType VT,
SDOperand Flag) {
const MVT::ValueType *VTs = getNodeValueTypes(VT, MVT::Other, MVT::Flag);
SDOperand Ops[] = { Chain, getRegister(Reg, VT), Flag };
return getNode(ISD::CopyFromReg, VTs, 3, Ops, Flag.Val ? 3 : 2);
}
SDOperand getCondCode(ISD::CondCode Cond);
/// getZeroExtendInReg - Return the expression required to zero extend the Op
/// value assuming it was the smaller SrcTy value.
SDOperand getZeroExtendInReg(SDOperand Op, MVT::ValueType SrcTy);
/// getCALLSEQ_START - Return a new CALLSEQ_START node, which always must have
/// a flag result (to ensure it's not CSE'd).
SDOperand getCALLSEQ_START(SDOperand Chain, SDOperand Op) {
const MVT::ValueType *VTs = getNodeValueTypes(MVT::Other, MVT::Flag);
SDOperand Ops[] = { Chain, Op };
return getNode(ISD::CALLSEQ_START, VTs, 2, Ops, 2);
}
/// getNode - Gets or creates the specified node.
///
SDOperand getNode(unsigned Opcode, MVT::ValueType VT);
SDOperand getNode(unsigned Opcode, MVT::ValueType VT, SDOperand N);
SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
SDOperand N1, SDOperand N2);
SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
SDOperand N1, SDOperand N2, SDOperand N3);
SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4);
SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4,
SDOperand N5);
SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
const SDOperand *Ops, unsigned NumOps);
SDOperand getNode(unsigned Opcode, std::vector<MVT::ValueType> &ResultTys,
const SDOperand *Ops, unsigned NumOps);
SDOperand getNode(unsigned Opcode, const MVT::ValueType *VTs, unsigned NumVTs,
const SDOperand *Ops, unsigned NumOps);
SDOperand getNode(unsigned Opcode, SDVTList VTs,
const SDOperand *Ops, unsigned NumOps);
/// getSetCC - Helper function to make it easier to build SetCC's if you just
/// have an ISD::CondCode instead of an SDOperand.
///
SDOperand getSetCC(MVT::ValueType VT, SDOperand LHS, SDOperand RHS,
ISD::CondCode Cond) {
return getNode(ISD::SETCC, VT, LHS, RHS, getCondCode(Cond));
}
/// getSelectCC - Helper function to make it easier to build SelectCC's if you
/// just have an ISD::CondCode instead of an SDOperand.
///
SDOperand getSelectCC(SDOperand LHS, SDOperand RHS,
SDOperand True, SDOperand False, ISD::CondCode Cond) {
return getNode(ISD::SELECT_CC, True.getValueType(), LHS, RHS, True, False,
getCondCode(Cond));
}
/// getVAArg - VAArg produces a result and token chain, and takes a pointer
/// and a source value as input.
SDOperand getVAArg(MVT::ValueType VT, SDOperand Chain, SDOperand Ptr,
SDOperand SV);
/// getLoad - Loads are not normal binary operators: their result type is not
/// determined by their operands, and they produce a value AND a token chain.
///
SDOperand getLoad(MVT::ValueType VT, SDOperand Chain, SDOperand Ptr,
SDOperand SV);
SDOperand getVecLoad(unsigned Count, MVT::ValueType VT, SDOperand Chain,
SDOperand Ptr, SDOperand SV);
SDOperand getExtLoad(ISD::LoadExtType LType, MVT::ValueType VT,
SDOperand Chain, SDOperand Ptr, SDOperand SV,
MVT::ValueType EVT);
/// getStore - Helper function to build ISD::STORE nodes.
///
SDOperand getStore(SDOperand Chain, SDOperand Value, SDOperand Ptr,
SDOperand SV);
// getSrcValue - construct a node to track a Value* through the backend
SDOperand getSrcValue(const Value* I, int offset = 0);
/// UpdateNodeOperands - *Mutate* the specified node in-place to have the
/// specified operands. If the resultant node already exists in the DAG,
/// this does not modify the specified node, instead it returns the node that
/// already exists. If the resultant node does not exist in the DAG, the
/// input node is returned. As a degenerate case, if you specify the same
/// input operands as the node already has, the input node is returned.
SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op);
SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2);
SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
SDOperand Op3);
SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
SDOperand Op3, SDOperand Op4);
SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
SDOperand Op3, SDOperand Op4, SDOperand Op5);
SDOperand UpdateNodeOperands(SDOperand N, SDOperand *Ops, unsigned NumOps);
/// SelectNodeTo - These are used for target selectors to *mutate* the
/// specified node to have the specified return type, Target opcode, and
/// operands. Note that target opcodes are stored as
/// ISD::BUILTIN_OP_END+TargetOpcode in the node opcode field. The 0th value
/// of the resultant node is returned.
SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT);
SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
SDOperand Op1);
SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
SDOperand Op1, SDOperand Op2);
SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
SDOperand Op1, SDOperand Op2, SDOperand Op3);
SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
const SDOperand *Ops, unsigned NumOps);
SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
MVT::ValueType VT2, SDOperand Op1, SDOperand Op2);
SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
SDOperand Op3);
/// getTargetNode - These are used for target selectors to create a new node
/// with specified return type(s), target opcode, and operands.
///
/// Note that getTargetNode returns the resultant node. If there is already a
/// node of the specified opcode and operands, it returns that node instead of
/// the current one.
SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT);
SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
SDOperand Op1);
SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
SDOperand Op1, SDOperand Op2);
SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
SDOperand Op1, SDOperand Op2, SDOperand Op3);
SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
const SDOperand *Ops, unsigned NumOps);
SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
MVT::ValueType VT2, SDOperand Op1);
SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
MVT::ValueType VT2, SDOperand Op1, SDOperand Op2);
SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
SDOperand Op3);
SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
MVT::ValueType VT2,
const SDOperand *Ops, unsigned NumOps);
SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
MVT::ValueType VT2, MVT::ValueType VT3,
SDOperand Op1, SDOperand Op2);
SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
MVT::ValueType VT2, MVT::ValueType VT3,
const SDOperand *Ops, unsigned NumOps);
/// ReplaceAllUsesWith - Modify anything using 'From' to use 'To' instead.
/// This can cause recursive merging of nodes in the DAG. Use the first
/// version if 'From' is known to have a single result, use the second
/// if you have two nodes with identical results, use the third otherwise.
///
/// These methods all take an optional vector, which (if not null) is
/// populated with any nodes that are deleted from the SelectionDAG, due to
/// new equivalences that are discovered.
///
void ReplaceAllUsesWith(SDOperand From, SDOperand Op,
std::vector<SDNode*> *Deleted = 0);
void ReplaceAllUsesWith(SDNode *From, SDNode *To,
std::vector<SDNode*> *Deleted = 0);
void ReplaceAllUsesWith(SDNode *From, const SDOperand *To,
std::vector<SDNode*> *Deleted = 0);
/// ReplaceAllUsesOfValueWith - Replace any uses of From with To, leaving
/// uses of other values produced by From.Val alone. The Deleted vector is
/// handled the same was as for ReplaceAllUsesWith, but it is required for
/// this method.
void ReplaceAllUsesOfValueWith(SDOperand From, SDOperand To,
std::vector<SDNode*> &Deleted);
/// DeleteNode - Remove the specified node from the system. This node must
/// have no referrers.
void DeleteNode(SDNode *N);
/// AssignNodeIds - Assign a unique node id for each node in the DAG based on
/// their allnodes order. It returns the maximum id.
unsigned AssignNodeIds();
/// AssignTopologicalOrder - Assign a unique node id for each node in the DAG
/// based on their topological order. It returns the maximum id and a vector
/// of the SDNodes* in assigned order by reference.
unsigned AssignTopologicalOrder(std::vector<SDNode*> &TopOrder);
/// isCommutativeBinOp - Returns true if the opcode is a commutative binary
/// operation.
static bool isCommutativeBinOp(unsigned Opcode) {
switch (Opcode) {
case ISD::ADD:
case ISD::MUL:
case ISD::MULHU:
case ISD::MULHS:
case ISD::FADD:
case ISD::FMUL:
case ISD::AND:
case ISD::OR:
case ISD::XOR:
case ISD::ADDC:
case ISD::ADDE: return true;
default: return false;
}
}
void dump() const;
private:
void RemoveNodeFromCSEMaps(SDNode *N);
SDNode *AddNonLeafNodeToCSEMaps(SDNode *N);
SDNode *FindModifiedNodeSlot(SDNode *N, SDOperand Op, void *&InsertPos);
SDNode *FindModifiedNodeSlot(SDNode *N, SDOperand Op1, SDOperand Op2,
void *&InsertPos);
SDNode *FindModifiedNodeSlot(SDNode *N, const SDOperand *Ops, unsigned NumOps,
void *&InsertPos);
void DeleteNodeNotInCSEMaps(SDNode *N);
/// SimplifySetCC - Try to simplify a setcc built with the specified operands
/// and cc. If unable to simplify it, return a null SDOperand.
SDOperand SimplifySetCC(MVT::ValueType VT, SDOperand N1,
SDOperand N2, ISD::CondCode Cond);
// List of non-single value types.
std::list<std::vector<MVT::ValueType> > VTList;
// Maps to auto-CSE operations.
std::vector<CondCodeSDNode*> CondCodeNodes;
std::vector<SDNode*> ValueTypeNodes;
std::map<std::string, SDNode*> ExternalSymbols;
std::map<std::string, SDNode*> TargetExternalSymbols;
std::map<std::string, StringSDNode*> StringNodes;
};
template <> struct GraphTraits<SelectionDAG*> : public GraphTraits<SDNode*> {
typedef SelectionDAG::allnodes_iterator nodes_iterator;
static nodes_iterator nodes_begin(SelectionDAG *G) {
return G->allnodes_begin();
}
static nodes_iterator nodes_end(SelectionDAG *G) {
return G->allnodes_end();
}
};
} // end namespace llvm
#endif