llvm-6502/lib/Target/MBlaze/MBlazeISelDAGToDAG.cpp
Chris Lattner 7c306da505 Sink InstructionSelect() out of each target into SDISel, and rename it
DoInstructionSelection.  Inline "SelectRoot" into it from DAGISelHeader.
Sink some other stuff out of DAGISelHeader into SDISel.

Eliminate the various 'Indent' stuff from various targets, which dates
to when isel was recursive.

 17 files changed, 114 insertions(+), 430 deletions(-)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97555 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-02 06:34:30 +00:00

340 lines
12 KiB
C++

//===-- MBlazeISelDAGToDAG.cpp - A dag to dag inst selector for MBlaze ----===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines an instruction selector for the MBlaze target.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "mblaze-isel"
#include "MBlaze.h"
#include "MBlazeISelLowering.h"
#include "MBlazeMachineFunction.h"
#include "MBlazeRegisterInfo.h"
#include "MBlazeSubtarget.h"
#include "MBlazeTargetMachine.h"
#include "llvm/GlobalValue.h"
#include "llvm/Instructions.h"
#include "llvm/Intrinsics.h"
#include "llvm/Support/CFG.h"
#include "llvm/Type.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/SelectionDAGISel.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
// Instruction Selector Implementation
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
// MBlazeDAGToDAGISel - MBlaze specific code to select MBlaze machine
// instructions for SelectionDAG operations.
//===----------------------------------------------------------------------===//
namespace {
class MBlazeDAGToDAGISel : public SelectionDAGISel {
/// TM - Keep a reference to MBlazeTargetMachine.
MBlazeTargetMachine &TM;
/// Subtarget - Keep a pointer to the MBlazeSubtarget around so that we can
/// make the right decision when generating code for different targets.
const MBlazeSubtarget &Subtarget;
public:
explicit MBlazeDAGToDAGISel(MBlazeTargetMachine &tm) :
SelectionDAGISel(tm),
TM(tm), Subtarget(tm.getSubtarget<MBlazeSubtarget>()) {}
// Pass Name
virtual const char *getPassName() const {
return "MBlaze DAG->DAG Pattern Instruction Selection";
}
private:
// Include the pieces autogenerated from the target description.
#include "MBlazeGenDAGISel.inc"
/// getTargetMachine - Return a reference to the TargetMachine, casted
/// to the target-specific type.
const MBlazeTargetMachine &getTargetMachine() {
return static_cast<const MBlazeTargetMachine &>(TM);
}
/// getInstrInfo - Return a reference to the TargetInstrInfo, casted
/// to the target-specific type.
const MBlazeInstrInfo *getInstrInfo() {
return getTargetMachine().getInstrInfo();
}
SDNode *getGlobalBaseReg();
SDNode *Select(SDNode *N);
// Complex Pattern.
bool SelectAddr(SDNode *Op, SDValue N,
SDValue &Base, SDValue &Offset);
// Address Selection
bool SelectAddrRegReg(SDNode *Op, SDValue N, SDValue &Base, SDValue &Index);
bool SelectAddrRegImm(SDNode *Op, SDValue N, SDValue &Disp, SDValue &Base);
// getI32Imm - Return a target constant with the specified value, of type i32.
inline SDValue getI32Imm(unsigned Imm) {
return CurDAG->getTargetConstant(Imm, MVT::i32);
}
};
}
/// isIntS32Immediate - This method tests to see if the node is either a 32-bit
/// or 64-bit immediate, and if the value can be accurately represented as a
/// sign extension from a 32-bit value. If so, this returns true and the
/// immediate.
static bool isIntS32Immediate(SDNode *N, int32_t &Imm) {
unsigned Opc = N->getOpcode();
if (Opc != ISD::Constant)
return false;
Imm = (int32_t)cast<ConstantSDNode>(N)->getZExtValue();
if (N->getValueType(0) == MVT::i32)
return Imm == (int32_t)cast<ConstantSDNode>(N)->getZExtValue();
else
return Imm == (int64_t)cast<ConstantSDNode>(N)->getZExtValue();
}
static bool isIntS32Immediate(SDValue Op, int32_t &Imm) {
return isIntS32Immediate(Op.getNode(), Imm);
}
/// SelectAddressRegReg - Given the specified addressed, check to see if it
/// can be represented as an indexed [r+r] operation. Returns false if it
/// can be more efficiently represented with [r+imm].
bool MBlazeDAGToDAGISel::
SelectAddrRegReg(SDNode *Op, SDValue N, SDValue &Base, SDValue &Index) {
if (N.getOpcode() == ISD::FrameIndex) return false;
if (N.getOpcode() == ISD::TargetExternalSymbol ||
N.getOpcode() == ISD::TargetGlobalAddress)
return false; // direct calls.
if (N.getOperand(0).getOpcode() == ISD::TargetJumpTable ||
N.getOperand(1).getOpcode() == ISD::TargetJumpTable)
return false; // jump tables.
int32_t imm = 0;
if (N.getOpcode() == ISD::ADD || N.getOpcode() == ISD::OR) {
if (isIntS32Immediate(N.getOperand(1), imm))
return false; // r+i
Base = N.getOperand(1);
Index = N.getOperand(0);
return true;
}
return false;
}
/// Returns true if the address N can be represented by a base register plus
/// a signed 32-bit displacement [r+imm], and if it is not better
/// represented as reg+reg.
bool MBlazeDAGToDAGISel::
SelectAddrRegImm(SDNode *Op, SDValue N, SDValue &Disp, SDValue &Base) {
// If this can be more profitably realized as r+r, fail.
if (SelectAddrRegReg(Op, N, Disp, Base))
return false;
if (N.getOpcode() == ISD::ADD || N.getOpcode() == ISD::OR) {
int32_t imm = 0;
if (isIntS32Immediate(N.getOperand(1), imm)) {
Disp = CurDAG->getTargetConstant(imm, MVT::i32);
if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(N.getOperand(0))) {
Base = CurDAG->getTargetFrameIndex(FI->getIndex(), N.getValueType());
} else {
Base = N.getOperand(0);
}
DEBUG( errs() << "WESLEY: Using Operand Immediate\n" );
return true; // [r+i]
}
} else if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N)) {
// Loading from a constant address.
uint32_t Imm = CN->getZExtValue();
Disp = CurDAG->getTargetConstant(Imm, CN->getValueType(0));
Base = CurDAG->getRegister(MBlaze::R0, CN->getValueType(0));
DEBUG( errs() << "WESLEY: Using Constant Node\n" );
return true;
}
Disp = CurDAG->getTargetConstant(0, TM.getTargetLowering()->getPointerTy());
if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(N))
Base = CurDAG->getTargetFrameIndex(FI->getIndex(), N.getValueType());
else
Base = N;
return true; // [r+0]
}
/// getGlobalBaseReg - Output the instructions required to put the
/// GOT address into a register.
SDNode *MBlazeDAGToDAGISel::getGlobalBaseReg() {
unsigned GlobalBaseReg = getInstrInfo()->getGlobalBaseReg(MF);
return CurDAG->getRegister(GlobalBaseReg, TLI.getPointerTy()).getNode();
}
/// ComplexPattern used on MBlazeInstrInfo
/// Used on MBlaze Load/Store instructions
bool MBlazeDAGToDAGISel::
SelectAddr(SDNode *Op, SDValue Addr, SDValue &Offset, SDValue &Base) {
// if Address is FI, get the TargetFrameIndex.
if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(Addr)) {
Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i32);
Offset = CurDAG->getTargetConstant(0, MVT::i32);
return true;
}
// on PIC code Load GA
if (TM.getRelocationModel() == Reloc::PIC_) {
if ((Addr.getOpcode() == ISD::TargetGlobalAddress) ||
(Addr.getOpcode() == ISD::TargetConstantPool) ||
(Addr.getOpcode() == ISD::TargetJumpTable)){
Base = CurDAG->getRegister(MBlaze::R15, MVT::i32);
Offset = Addr;
return true;
}
} else {
if ((Addr.getOpcode() == ISD::TargetExternalSymbol ||
Addr.getOpcode() == ISD::TargetGlobalAddress))
return false;
}
// Operand is a result from an ADD.
if (Addr.getOpcode() == ISD::ADD) {
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1))) {
if (Predicate_immSExt16(CN)) {
// If the first operand is a FI, get the TargetFI Node
if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>
(Addr.getOperand(0))) {
Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i32);
} else {
Base = Addr.getOperand(0);
}
Offset = CurDAG->getTargetConstant(CN->getZExtValue(), MVT::i32);
return true;
}
}
}
Base = Addr;
Offset = CurDAG->getTargetConstant(0, MVT::i32);
return true;
}
/// Select instructions not customized! Used for
/// expanded, promoted and normal instructions
SDNode* MBlazeDAGToDAGISel::Select(SDNode *Node) {
unsigned Opcode = Node->getOpcode();
DebugLoc dl = Node->getDebugLoc();
// Dump information about the Node being selected
DEBUG(errs() << "Selecting: "; Node->dump(CurDAG); errs() << "\n");
// If we have a custom node, we already have selected!
if (Node->isMachineOpcode()) {
DEBUG(errs() << "== "; Node->dump(CurDAG); errs() << "\n");
return NULL;
}
///
// Instruction Selection not handled by the auto-generated
// tablegen selection should be handled here.
///
switch(Opcode) {
default: break;
// Get target GOT address.
case ISD::GLOBAL_OFFSET_TABLE:
return getGlobalBaseReg();
case ISD::FrameIndex: {
SDValue imm = CurDAG->getTargetConstant(0, MVT::i32);
int FI = dyn_cast<FrameIndexSDNode>(Node)->getIndex();
EVT VT = Node->getValueType(0);
SDValue TFI = CurDAG->getTargetFrameIndex(FI, VT);
unsigned Opc = MBlaze::ADDI;
if (Node->hasOneUse())
return CurDAG->SelectNodeTo(Node, Opc, VT, TFI, imm);
return CurDAG->getMachineNode(Opc, dl, VT, TFI, imm);
}
/// Handle direct and indirect calls when using PIC. On PIC, when
/// GOT is smaller than about 64k (small code) the GA target is
/// loaded with only one instruction. Otherwise GA's target must
/// be loaded with 3 instructions.
case MBlazeISD::JmpLink: {
if (TM.getRelocationModel() == Reloc::PIC_) {
SDValue Chain = Node->getOperand(0);
SDValue Callee = Node->getOperand(1);
SDValue R20Reg = CurDAG->getRegister(MBlaze::R20, MVT::i32);
SDValue InFlag(0, 0);
if ( (isa<GlobalAddressSDNode>(Callee)) ||
(isa<ExternalSymbolSDNode>(Callee)) )
{
/// Direct call for global addresses and external symbols
SDValue GPReg = CurDAG->getRegister(MBlaze::R15, MVT::i32);
// Use load to get GOT target
SDValue Ops[] = { Callee, GPReg, Chain };
SDValue Load = SDValue(CurDAG->getMachineNode(MBlaze::LW, dl,
MVT::i32, MVT::Other, Ops, 3), 0);
Chain = Load.getValue(1);
// Call target must be on T9
Chain = CurDAG->getCopyToReg(Chain, dl, R20Reg, Load, InFlag);
} else
/// Indirect call
Chain = CurDAG->getCopyToReg(Chain, dl, R20Reg, Callee, InFlag);
// Emit Jump and Link Register
SDNode *ResNode = CurDAG->getMachineNode(MBlaze::BRLID, dl, MVT::Other,
MVT::Flag, R20Reg, Chain);
Chain = SDValue(ResNode, 0);
InFlag = SDValue(ResNode, 1);
ReplaceUses(SDValue(Node, 0), Chain);
ReplaceUses(SDValue(Node, 1), InFlag);
return ResNode;
}
}
}
// Select the default instruction
SDNode *ResNode = SelectCode(Node);
DEBUG(errs() << "=> ");
if (ResNode == NULL || ResNode == Node)
DEBUG(Node->dump(CurDAG));
else
DEBUG(ResNode->dump(CurDAG));
DEBUG(errs() << "\n");
return ResNode;
}
/// createMBlazeISelDag - This pass converts a legalized DAG into a
/// MBlaze-specific DAG, ready for instruction scheduling.
FunctionPass *llvm::createMBlazeISelDag(MBlazeTargetMachine &TM) {
return new MBlazeDAGToDAGISel(TM);
}