llvm-6502/include/llvm/CodeGen/SelectionDAGISel.h
Anton Korobeynikov 5502bf67cd Properly emit range comparisons for switch cases, where neighbour cases
go to the same destination. Now we're producing really good code for
switch-lower-feature.ll testcase


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35672 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-04 21:14:49 +00:00

165 lines
6.4 KiB
C++

//===-- llvm/CodeGen/SelectionDAGISel.h - Common Base Class------*- 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 implements the SelectionDAGISel class, which is used as the common
// base class for SelectionDAG-based instruction selectors.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_SELECTIONDAG_ISEL_H
#define LLVM_CODEGEN_SELECTIONDAG_ISEL_H
#include "llvm/Pass.h"
#include "llvm/Constant.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/SelectionDAGNodes.h"
namespace llvm {
class SelectionDAGLowering;
class SDOperand;
class SSARegMap;
class MachineBasicBlock;
class MachineFunction;
class MachineInstr;
class TargetLowering;
class FunctionLoweringInfo;
class HazardRecognizer;
/// SelectionDAGISel - This is the common base class used for SelectionDAG-based
/// pattern-matching instruction selectors.
class SelectionDAGISel : public FunctionPass {
public:
TargetLowering &TLI;
SSARegMap *RegMap;
SelectionDAG *CurDAG;
MachineBasicBlock *BB;
std::vector<SDNode*> TopOrder;
unsigned DAGSize;
explicit SelectionDAGISel(TargetLowering &tli) : TLI(tli), DAGSize(0) {}
TargetLowering &getTargetLowering() { return TLI; }
virtual void getAnalysisUsage(AnalysisUsage &AU) const;
virtual bool runOnFunction(Function &Fn);
unsigned MakeReg(MVT::ValueType VT);
virtual void EmitFunctionEntryCode(Function &Fn, MachineFunction &MF) {}
virtual void InstructionSelectBasicBlock(SelectionDAG &SD) = 0;
virtual void SelectRootInit() {
DAGSize = CurDAG->AssignTopologicalOrder(TopOrder);
}
/// SelectInlineAsmMemoryOperand - Select the specified address as a target
/// addressing mode, according to the specified constraint code. If this does
/// not match or is not implemented, return true. The resultant operands
/// (which will appear in the machine instruction) should be added to the
/// OutOps vector.
virtual bool SelectInlineAsmMemoryOperand(const SDOperand &Op,
char ConstraintCode,
std::vector<SDOperand> &OutOps,
SelectionDAG &DAG) {
return true;
}
/// CanBeFoldedBy - Returns true if the specific operand node N of U can be
/// folded during instruction selection that starts at Root?
virtual bool CanBeFoldedBy(SDNode *N, SDNode *U, SDNode *Root) { return true;}
/// CreateTargetHazardRecognizer - Return a newly allocated hazard recognizer
/// to use for this target when scheduling the DAG.
virtual HazardRecognizer *CreateTargetHazardRecognizer();
/// CaseBlock - This structure is used to communicate between SDLowering and
/// SDISel for the code generation of additional basic blocks needed by multi-
/// case switch statements.
struct CaseBlock {
CaseBlock(ISD::CondCode cc, Value *cmplhs, Value *cmprhs, Value *cmpmiddle,
MachineBasicBlock *truebb, MachineBasicBlock *falsebb,
MachineBasicBlock *me)
: CC(cc), CmpLHS(cmplhs), CmpMHS(cmpmiddle), CmpRHS(cmprhs),
TrueBB(truebb), FalseBB(falsebb), ThisBB(me) {}
// CC - the condition code to use for the case block's setcc node
ISD::CondCode CC;
// CmpLHS/CmpRHS/CmpMHS - The LHS/MHS/RHS of the comparison to emit.
// Emit by default LHS op RHS. MHS is used for range comparisons:
// If MHS is not null: (LHS <= MHS) and (MHS <= RHS).
Value *CmpLHS, *CmpMHS, *CmpRHS;
// TrueBB/FalseBB - the block to branch to if the setcc is true/false.
MachineBasicBlock *TrueBB, *FalseBB;
// ThisBB - the block into which to emit the code for the setcc and branches
MachineBasicBlock *ThisBB;
};
struct JumpTable {
JumpTable(unsigned R, unsigned J, MachineBasicBlock *M,
MachineBasicBlock *D): Reg(R), JTI(J), MBB(M), Default(D) {};
/// Reg - the virtual register containing the index of the jump table entry
//. to jump to.
unsigned Reg;
/// JTI - the JumpTableIndex for this jump table in the function.
unsigned JTI;
/// MBB - the MBB into which to emit the code for the indirect jump.
MachineBasicBlock *MBB;
/// Default - the MBB of the default bb, which is a successor of the range
/// check MBB. This is when updating PHI nodes in successors.
MachineBasicBlock *Default;
};
struct JumpTableHeader {
JumpTableHeader(uint64_t F, uint64_t L, Value* SV, MachineBasicBlock* H,
bool E = false):
First(F), Last(L), SValue(SV), HeaderBB(H), Emitted(E) {};
uint64_t First;
uint64_t Last;
Value *SValue;
MachineBasicBlock *HeaderBB;
bool Emitted;
};
typedef std::pair<JumpTableHeader, JumpTable> JumpTableBlock;
protected:
/// Pick a safe ordering and emit instructions for each target node in the
/// graph.
void ScheduleAndEmitDAG(SelectionDAG &DAG);
/// SelectInlineAsmMemoryOperands - Calls to this are automatically generated
/// by tblgen. Others should not call it.
void SelectInlineAsmMemoryOperands(std::vector<SDOperand> &Ops,
SelectionDAG &DAG);
// Calls to these predicates are generated by tblgen.
bool CheckAndMask(SDOperand LHS, ConstantSDNode *RHS, int64_t DesiredMaskS);
bool CheckOrMask(SDOperand LHS, ConstantSDNode *RHS, int64_t DesiredMaskS);
private:
void SelectBasicBlock(BasicBlock *BB, MachineFunction &MF,
FunctionLoweringInfo &FuncInfo);
void BuildSelectionDAG(SelectionDAG &DAG, BasicBlock *LLVMBB,
std::vector<std::pair<MachineInstr*, unsigned> > &PHINodesToUpdate,
FunctionLoweringInfo &FuncInfo);
void CodeGenAndEmitDAG(SelectionDAG &DAG);
void LowerArguments(BasicBlock *BB, SelectionDAGLowering &SDL,
std::vector<SDOperand> &UnorderedChains);
/// SwitchCases - Vector of CaseBlock structures used to communicate
/// SwitchInst code generation information.
std::vector<CaseBlock> SwitchCases;
/// JTCases - Vector of JumpTable structures which holds necessary information
/// for emitting a jump tables during SwitchInst code generation.
std::vector<JumpTableBlock> JTCases;
};
}
#endif /* LLVM_CODEGEN_SELECTIONDAG_ISEL_H */