//===-- M68kISelDAGToDAG.cpp - M68k Dag to Dag Inst Selector ----*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
///
/// \file
/// This file defines an instruction selector for the M68K target.
///
//===----------------------------------------------------------------------===//
#include "M68k.h"
#include "M68kMachineFunction.h"
#include "M68kRegisterInfo.h"
#include "M68kTargetMachine.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/SelectionDAGISel.h"
#include "llvm/CodeGen/SelectionDAGNodes.h"
#include "llvm/IR/CFG.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/Type.h"
#include "llvm/Support/Alignment.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
using namespace llvm;
#define DEBUG_TYPE "m68k-isel"
#define PASS_NAME "M68k DAG->DAG Pattern Instruction Selection"
namespace {
// For reference, the full order of operands for memory references is:
// (Operand), Displacement, Base, Index, Scale
struct M68kISelAddressMode {
enum class AddrType {
ARI, // Address Register Indirect
ARIPI, // Address Register Indirect with Postincrement
ARIPD, // Address Register Indirect with Postdecrement
ARID, // Address Register Indirect with Displacement
ARII, // Address Register Indirect with Index
PCD, // Program Counter Indirect with Displacement
PCI, // Program Counter Indirect with Index
AL, // Absolute
};
AddrType AM;
enum class Base { RegBase, FrameIndexBase };
Base BaseType;
int64_t Disp;
// This is really a union, discriminated by BaseType!
SDValue BaseReg;
int BaseFrameIndex;
SDValue IndexReg;
unsigned Scale;
const GlobalValue *GV;
const Constant *CP;
const BlockAddress *BlockAddr;
const char *ES;
MCSymbol *MCSym;
int JT;
Align Alignment; // CP alignment.
unsigned char SymbolFlags; // M68kII::MO_*
M68kISelAddressMode(AddrType AT)
: AM(AT), BaseType(Base::RegBase), Disp(0), BaseFrameIndex(0), IndexReg(),
Scale(1), GV(nullptr), CP(nullptr), BlockAddr(nullptr), ES(nullptr),
MCSym(nullptr), JT(-1), Alignment(), SymbolFlags(M68kII::MO_NO_FLAG) {}
bool hasSymbolicDisplacement() const {
return GV != nullptr || CP != nullptr || ES != nullptr ||
MCSym != nullptr || JT != -1 || BlockAddr != nullptr;
}
bool hasBase() const {
return BaseType == Base::FrameIndexBase || BaseReg.getNode() != nullptr;
}
bool hasFrameIndex() const { return BaseType == Base::FrameIndexBase; }
bool hasBaseReg() const {
return BaseType == Base::RegBase && BaseReg.getNode() != nullptr;
}
bool hasIndexReg() const {
return BaseType == Base::RegBase && IndexReg.getNode() != nullptr;
}
/// True if address mode type supports displacement
bool isDispAddrType() const {
return AM == AddrType::ARII || AM == AddrType::PCI ||
AM == AddrType::ARID || AM == AddrType::PCD || AM == AddrType::AL;
}
unsigned getDispSize() const {
switch (AM) {
default:
return 0;
case AddrType::ARII:
case AddrType::PCI:
return 8;
// These two in the next chip generations can hold upto 32 bit
case AddrType::ARID:
case AddrType::PCD:
return 16;
case AddrType::AL:
return 32;
}
}
bool hasDisp() const { return getDispSize() != 0; }
bool isDisp8() const { return getDispSize() == 8; }
bool isDisp16() const { return getDispSize() == 16; }
bool isDisp32() const { return getDispSize() == 32; }
/// Return true if this addressing mode is already PC-relative.
bool isPCRelative() const {
if (BaseType != Base::RegBase)
return false;
if (auto *RegNode = dyn_cast_or_null<RegisterSDNode>(BaseReg.getNode()))
return RegNode->getReg() == M68k::PC;
return false;
}
void setBaseReg(SDValue Reg) {
BaseType = Base::RegBase;
BaseReg = Reg;
}
void setIndexReg(SDValue Reg) { IndexReg = Reg; }
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void dump() {
dbgs() << "M68kISelAddressMode " << this;
dbgs() << "\nDisp: " << Disp;
dbgs() << ", BaseReg: ";
if (BaseReg.getNode())
BaseReg.getNode()->dump();
else
dbgs() << "null";
dbgs() << ", BaseFI: " << BaseFrameIndex;
dbgs() << ", IndexReg: ";
if (IndexReg.getNode()) {
IndexReg.getNode()->dump();
} else {
dbgs() << "null";
dbgs() << ", Scale: " << Scale;
}
dbgs() << '\n';
}
#endif
};
} // end anonymous namespace
namespace {
class M68kDAGToDAGISel : public SelectionDAGISel {
public:
M68kDAGToDAGISel() = delete;
explicit M68kDAGToDAGISel(M68kTargetMachine &TM)
: SelectionDAGISel(TM), Subtarget(nullptr) {}
bool runOnMachineFunction(MachineFunction &MF) override;
bool IsProfitableToFold(SDValue N, SDNode *U, SDNode *Root) const override;
private:
/// Keep a pointer to the M68kSubtarget around so that we can
/// make the right decision when generating code for different targets.
const M68kSubtarget *Subtarget;
// Include the pieces autogenerated from the target description.
#include "M68kGenDAGISel.inc"
/// getTargetMachine - Return a reference to the TargetMachine, casted
/// to the target-specific type.
const M68kTargetMachine &getTargetMachine() {
return static_cast<const M68kTargetMachine &>(TM);
}
void Select(SDNode *N) override;
// Insert instructions to initialize the global base register in the
// first MBB of the function.
// HMM... do i need this?
void initGlobalBaseReg(MachineFunction &MF);
bool foldOffsetIntoAddress(uint64_t Offset, M68kISelAddressMode &AM);
bool matchLoadInAddress(LoadSDNode *N, M68kISelAddressMode &AM);
bool matchAddress(SDValue N, M68kISelAddressMode &AM);
bool matchAddressBase(SDValue N, M68kISelAddressMode &AM);
bool matchAddressRecursively(SDValue N, M68kISelAddressMode &AM,
unsigned Depth);
bool matchADD(SDValue &N, M68kISelAddressMode &AM, unsigned Depth);
bool matchWrapper(SDValue N, M68kISelAddressMode &AM);
std::pair<bool, SDNode *> selectNode(SDNode *Node);
bool SelectARI(SDNode *Parent, SDValue N, SDValue &Base);
bool SelectARIPI(SDNode *Parent, SDValue N, SDValue &Base);
bool SelectARIPD(SDNode *Parent, SDValue N, SDValue &Base);
bool SelectARID(SDNode *Parent, SDValue N, SDValue &Imm, SDValue &Base);
bool SelectARII(SDNode *Parent, SDValue N, SDValue &Imm, SDValue &Base,
SDValue &Index);
bool SelectAL(SDNode *Parent, SDValue N, SDValue &Sym);
bool SelectPCD(SDNode *Parent, SDValue N, SDValue &Imm);
bool SelectPCI(SDNode *Parent, SDValue N, SDValue &Imm, SDValue &Index);
bool SelectInlineAsmMemoryOperand(const SDValue &Op,
InlineAsm::ConstraintCode ConstraintID,
std::vector<SDValue> &OutOps) override;
// If Address Mode represents Frame Index store FI in Disp and
// Displacement bit size in Base. These values are read symmetrically by
// M68kRegisterInfo::eliminateFrameIndex method
inline bool getFrameIndexAddress(M68kISelAddressMode &AM, const SDLoc &DL,
SDValue &Disp, SDValue &Base) {
if (AM.BaseType == M68kISelAddressMode::Base::FrameIndexBase) {
Disp = getI32Imm(AM.Disp, DL);
Base = CurDAG->getTargetFrameIndex(
AM.BaseFrameIndex, TLI->getPointerTy(CurDAG->getDataLayout()));
return true;
}
return false;
}
// Gets a symbol plus optional displacement
inline bool getSymbolicDisplacement(M68kISelAddressMode &AM, const SDLoc &DL,
SDValue &Sym) {
if (AM.GV) {
Sym = CurDAG->getTargetGlobalAddress(AM.GV, SDLoc(), MVT::i32, AM.Disp,
AM.SymbolFlags);
return true;
}
if (AM.CP) {
Sym = CurDAG->getTargetConstantPool(AM.CP, MVT::i32, AM.Alignment,
AM.Disp, AM.SymbolFlags);
return true;
}
if (AM.ES) {
assert(!AM.Disp && "Non-zero displacement is ignored with ES.");
Sym = CurDAG->getTargetExternalSymbol(AM.ES, MVT::i32, AM.SymbolFlags);
return true;
}
if (AM.MCSym) {
assert(!AM.Disp && "Non-zero displacement is ignored with MCSym.");
assert(AM.SymbolFlags == 0 && "oo");
Sym = CurDAG->getMCSymbol(AM.MCSym, MVT::i32);
return true;
}
if (AM.JT != -1) {
assert(!AM.Disp && "Non-zero displacement is ignored with JT.");
Sym = CurDAG->getTargetJumpTable(AM.JT, MVT::i32, AM.SymbolFlags);
return true;
}
if (AM.BlockAddr) {
Sym = CurDAG->getTargetBlockAddress(AM.BlockAddr, MVT::i32, AM.Disp,
AM.SymbolFlags);
return true;
}
return false;
}
/// Return a target constant with the specified value of type i8.
inline SDValue getI8Imm(int64_t Imm, const SDLoc &DL) {
return CurDAG->getTargetConstant(Imm, DL, MVT::i8);
}
/// Return a target constant with the specified value of type i8.
inline SDValue getI16Imm(int64_t Imm, const SDLoc &DL) {
return CurDAG->getTargetConstant(Imm, DL, MVT::i16);
}
/// Return a target constant with the specified value, of type i32.
inline SDValue getI32Imm(int64_t Imm, const SDLoc &DL) {
return CurDAG->getTargetConstant(Imm, DL, MVT::i32);
}
/// Return a reference to the TargetInstrInfo, casted to the target-specific
/// type.
const M68kInstrInfo *getInstrInfo() const {
return Subtarget->getInstrInfo();
}
/// Return an SDNode that returns the value of the global base register.
/// Output instructions required to initialize the global base register,
/// if necessary.
SDNode *getGlobalBaseReg();
};
class M68kDAGToDAGISelLegacy : public SelectionDAGISelLegacy {
public:
static char ID;
explicit M68kDAGToDAGISelLegacy(M68kTargetMachine &TM)
: SelectionDAGISelLegacy(ID, std::make_unique<M68kDAGToDAGISel>(TM)) {}
};
char M68kDAGToDAGISelLegacy::ID;
} // namespace
INITIALIZE_PASS(M68kDAGToDAGISelLegacy, DEBUG_TYPE, PASS_NAME, false, false)
bool M68kDAGToDAGISel::IsProfitableToFold(SDValue N, SDNode *U,
SDNode *Root) const {
if (OptLevel == CodeGenOptLevel::None)
return false;
if (U == Root) {
switch (U->getOpcode()) {
default:
return true;
case M68kISD::SUB:
case ISD::SUB:
// Prefer NEG instruction when zero subtracts a value.
// e.g.
// move.l #0, %d0
// sub.l (4,%sp), %d0
// vs.
// move.l (4,%sp), %d0
// neg.l %d0
if (llvm::isNullConstant(U->getOperand(0)))
return false;
break;
}
}
return true;
}
bool M68kDAGToDAGISel::runOnMachineFunction(MachineFunction &MF) {
Subtarget = &MF.getSubtarget<M68kSubtarget>();
return SelectionDAGISel::runOnMachineFunction(MF);
}
/// This pass converts a legalized DAG into a M68k-specific DAG,
/// ready for instruction scheduling.
FunctionPass *llvm::createM68kISelDag(M68kTargetMachine &TM) {
return new M68kDAGToDAGISelLegacy(TM);
}
static bool doesDispFitFI(M68kISelAddressMode &AM) {
if (!AM.isDispAddrType())
return false;
// -1 to make sure that resolved FI will fit into Disp field
return isIntN(AM.getDispSize() - 1, AM.Disp);
}
static bool doesDispFit(M68kISelAddressMode &AM, int64_t Val) {
if (!AM.isDispAddrType())
return false;
return isIntN(AM.getDispSize(), Val);
}
/// Return an SDNode that returns the value of the global base register.
/// Output instructions required to initialize the global base register,
/// if necessary.
SDNode *M68kDAGToDAGISel::getGlobalBaseReg() {
unsigned GlobalBaseReg = getInstrInfo()->getGlobalBaseReg(MF);
auto &DL = MF->getDataLayout();
return CurDAG->getRegister(GlobalBaseReg, TLI->getPointerTy(DL)).getNode();
}
bool M68kDAGToDAGISel::foldOffsetIntoAddress(uint64_t Offset,
M68kISelAddressMode &AM) {
// Cannot combine ExternalSymbol displacements with integer offsets.
if (Offset != 0 && (AM.ES || AM.MCSym))
return false;
int64_t Val = AM.Disp + Offset;
if (doesDispFit(AM, Val)) {
AM.Disp = Val;
return true;
}
return false;
}
//===----------------------------------------------------------------------===//
// Matchers
//===----------------------------------------------------------------------===//
/// Helper for MatchAddress. Add the specified node to the
/// specified addressing mode without any further recursion.
bool M68kDAGToDAGISel::matchAddressBase(SDValue N, M68kISelAddressMode &AM) {
// Is the base register already occupied?
if (AM.hasBase()) {
// If so, check to see if the scale index register is set.
if (!AM.hasIndexReg()) {
AM.IndexReg = N;
AM.Scale = 1;
return true;
}
// Otherwise, we cannot select it.
return false;
}
// Default, generate it as a register.
AM.BaseType = M68kISelAddressMode::Base::RegBase;
AM.BaseReg = N;
return true;
}
/// TODO Add TLS support
bool M68kDAGToDAGISel::matchLoadInAddress(LoadSDNode *N,
M68kISelAddressMode &AM) {
return false;
}
bool M68kDAGToDAGISel::matchAddressRecursively(SDValue N,
M68kISelAddressMode &AM,
unsigned Depth) {
SDLoc DL(N);
// Limit recursion.
if (Depth > 5)
return matchAddressBase(N, AM);
// If this is already a %PC relative address, we can only merge immediates
// into it. Instead of handling this in every case, we handle it here.
// PC relative addressing: %PC + 16-bit displacement!
if (AM.isPCRelative()) {
// FIXME JumpTable and ExternalSymbol address currently don't like
// displacements. It isn't very important, but should be fixed for
// consistency.
if (ConstantSDNode *Cst = dyn_cast<ConstantSDNode>(N))
if (foldOffsetIntoAddress(Cst->getSExtValue(), AM))
return true;
return false;
}
switch (N.getOpcode()) {
default:
break;
case ISD::Constant: {
uint64_t Val = cast<ConstantSDNode>(N)->getSExtValue();
if (foldOffsetIntoAddress(Val, AM))
return true;
break;
}
case M68kISD::Wrapper:
case M68kISD::WrapperPC:
if (matchWrapper(N, AM))
return true;
break;
case ISD::LOAD:
if (matchLoadInAddress(cast<LoadSDNode>(N), AM))
return true;
break;
case ISD::OR:
// We want to look through a transform in InstCombine and DAGCombiner that
// turns 'add' into 'or', so we can treat this 'or' exactly like an 'add'.
// Example: (or (and x, 1), (shl y, 3)) --> (add (and x, 1), (shl y, 3))
// An 'lea' can then be used to match the shift (multiply) and add:
// and $1, %esi
// lea (%rsi, %rdi, 8), %rax
if (CurDAG->haveNoCommonBitsSet(N.getOperand(0), N.getOperand(1)) &&
matchADD(N, AM, Depth))
return true;
break;
case ISD::ADD:
if (matchADD(N, AM, Depth))
return true;
break;
case ISD::FrameIndex:
if (AM.isDispAddrType() &&
AM.BaseType == M68kISelAddressMode::Base::RegBase &&
AM.BaseReg.getNode() == nullptr && doesDispFitFI(AM)) {
AM.BaseType = M68kISelAddressMode::Base::FrameIndexBase;
AM.BaseFrameIndex = cast<FrameIndexSDNode>(N)->getIndex();
return true;
}
break;
case ISD::TargetGlobalTLSAddress: {
GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(N);
AM.GV = GA->getGlobal();
AM.SymbolFlags = GA->getTargetFlags();
return true;
}
}
return matchAddressBase(N, AM);
}
/// Add the specified node to the specified addressing mode, returning true if
/// it cannot be done. This just pattern matches for the addressing mode.
bool M68kDAGToDAGISel::matchAddress(SDValue N, M68kISelAddressMode &AM) {
// TODO: Post-processing: Convert lea(,%reg,2) to lea(%reg,%reg), which has
// a smaller encoding and avoids a scaled-index.
// And make sure it is an indexed mode
// TODO: Post-processing: Convert foo to foo(%pc), even in non-PIC mode,
// because it has a smaller encoding.
// Make sure this must be done only if PC* modes are currently being matched
return matchAddressRecursively(N, AM, 0);
}
bool M68kDAGToDAGISel::matchADD(SDValue &N, M68kISelAddressMode &AM,
unsigned Depth) {
// Add an artificial use to this node so that we can keep track of
// it if it gets CSE'd with a different node.
HandleSDNode Handle(N);
M68kISelAddressMode Backup = AM;
if (matchAddressRecursively(N.getOperand(0), AM, Depth + 1) &&
matchAddressRecursively(Handle.getValue().getOperand(1), AM, Depth + 1)) {
return true;
}
AM = Backup;
// Try again after commuting the operands.
if (matchAddressRecursively(Handle.getValue().getOperand(1), AM, Depth + 1) &&
matchAddressRecursively(Handle.getValue().getOperand(0), AM, Depth + 1)) {
return true;
}
AM = Backup;
// If we couldn't fold both operands into the address at the same time,
// see if we can just put each operand into a register and fold at least
// the add.
if (!AM.hasBase() && !AM.hasIndexReg()) {
N = Handle.getValue();
AM.BaseReg = N.getOperand(0);
AM.IndexReg = N.getOperand(1);
AM.Scale = 1;
return true;
}
N = Handle.getValue();
return false;
}
/// Try to match M68kISD::Wrapper and M68kISD::WrapperPC nodes into an
/// addressing mode. These wrap things that will resolve down into a symbol
/// reference. If no match is possible, this returns true, otherwise it returns
/// false.
bool M68kDAGToDAGISel::matchWrapper(SDValue N, M68kISelAddressMode &AM) {
// If the addressing mode already has a symbol as the displacement, we can
// never match another symbol.
if (AM.hasSymbolicDisplacement())
return false;
SDValue N0 = N.getOperand(0);
if (N.getOpcode() == M68kISD::WrapperPC) {
// If cannot match here just restore the old version
M68kISelAddressMode Backup = AM;
if (AM.hasBase()) {
return false;
}
if (auto *G = dyn_cast<GlobalAddressSDNode>(N0)) {
AM.GV = G->getGlobal();
AM.SymbolFlags = G->getTargetFlags();
if (!foldOffsetIntoAddress(G->getOffset(), AM)) {
AM = Backup;
return false;
}
} else if (auto *CP = dyn_cast<ConstantPoolSDNode>(N0)) {
AM.CP = CP->getConstVal();
AM.Alignment = CP->getAlign();
AM.SymbolFlags = CP->getTargetFlags();
if (!foldOffsetIntoAddress(CP->getOffset(), AM)) {
AM = Backup;
return false;
}
} else if (auto *S = dyn_cast<ExternalSymbolSDNode>(N0)) {
AM.ES = S->getSymbol();
AM.SymbolFlags = S->getTargetFlags();
} else if (auto *S = dyn_cast<MCSymbolSDNode>(N0)) {
AM.MCSym = S->getMCSymbol();
} else if (auto *J = dyn_cast<JumpTableSDNode>(N0)) {
AM.JT = J->getIndex();
AM.SymbolFlags = J->getTargetFlags();
} else if (auto *BA = dyn_cast<BlockAddressSDNode>(N0)) {
AM.BlockAddr = BA->getBlockAddress();
AM.SymbolFlags = BA->getTargetFlags();
if (!foldOffsetIntoAddress(BA->getOffset(), AM)) {
AM = Backup;
return false;
}
} else
llvm_unreachable("Unhandled symbol reference node.");
AM.setBaseReg(CurDAG->getRegister(M68k::PC, MVT::i32));
return true;
}
// This wrapper requires 32bit disp/imm field for Medium CM
if (!AM.isDisp32()) {
return false;
}
if (N.getOpcode() == M68kISD::Wrapper) {
if (auto *G = dyn_cast<GlobalAddressSDNode>(N0)) {
AM.GV = G->getGlobal();
AM.Disp += G->getOffset();
AM.SymbolFlags = G->getTargetFlags();
} else if (auto *CP = dyn_cast<ConstantPoolSDNode>(N0)) {
AM.CP = CP->getConstVal();
AM.Alignment = CP->getAlign();
AM.Disp += CP->getOffset();
AM.SymbolFlags = CP->getTargetFlags();
} else if (auto *S = dyn_cast<ExternalSymbolSDNode>(N0)) {
AM.ES = S->getSymbol();
AM.SymbolFlags = S->getTargetFlags();
} else if (auto *S = dyn_cast<MCSymbolSDNode>(N0)) {
AM.MCSym = S->getMCSymbol();
} else if (auto *J = dyn_cast<JumpTableSDNode>(N0)) {
AM.JT = J->getIndex();
AM.SymbolFlags = J->getTargetFlags();
} else if (auto *BA = dyn_cast<BlockAddressSDNode>(N0)) {
AM.BlockAddr = BA->getBlockAddress();
AM.Disp += BA->getOffset();
AM.SymbolFlags = BA->getTargetFlags();
} else
llvm_unreachable("Unhandled symbol reference node.");
return true;
}
return false;
}
//===----------------------------------------------------------------------===//
// Selectors
//===----------------------------------------------------------------------===//
void M68kDAGToDAGISel::Select(SDNode *Node) {
unsigned Opcode = Node->getOpcode();
SDLoc DL(Node);
LLVM_DEBUG(dbgs() << "Selecting: "; Node->dump(CurDAG); dbgs() << '\n');
if (Node->isMachineOpcode()) {
LLVM_DEBUG(dbgs() << "== "; Node->dump(CurDAG); dbgs() << '\n');
Node->setNodeId(-1);
return; // Already selected.
}
switch (Opcode) {
default:
break;
case ISD::GLOBAL_OFFSET_TABLE: {
SDValue GOT = CurDAG->getTargetExternalSymbol(
"_GLOBAL_OFFSET_TABLE_", MVT::i32, M68kII::MO_GOTPCREL);
MachineSDNode *Res =
CurDAG->getMachineNode(M68k::LEA32q, DL, MVT::i32, GOT);
ReplaceNode(Node, Res);
return;
}
case M68kISD::GLOBAL_BASE_REG:
ReplaceNode(Node, getGlobalBaseReg());
return;
}
SelectCode(Node);
}
bool M68kDAGToDAGISel::SelectARIPI(SDNode *Parent, SDValue N, SDValue &Base) {
LLVM_DEBUG(dbgs() << "Selecting AddrType::ARIPI: ");
LLVM_DEBUG(dbgs() << "NOT IMPLEMENTED\n");
return false;
}
bool M68kDAGToDAGISel::SelectARIPD(SDNode *Parent, SDValue N, SDValue &Base) {
LLVM_DEBUG(dbgs() << "Selecting AddrType::ARIPD: ");
LLVM_DEBUG(dbgs() << "NOT IMPLEMENTED\n");
return false;
}
bool M68kDAGToDAGISel::SelectARID(SDNode *Parent, SDValue N, SDValue &Disp,
SDValue &Base) {
LLVM_DEBUG(dbgs() << "Selecting AddrType::ARID: ");
M68kISelAddressMode AM(M68kISelAddressMode::AddrType::ARID);
if (!matchAddress(N, AM))
return false;
if (AM.isPCRelative()) {
LLVM_DEBUG(dbgs() << "REJECT: Cannot match PC relative address\n");
return false;
}
// If this is a frame index, grab it
if (getFrameIndexAddress(AM, SDLoc(N), Disp, Base)) {
LLVM_DEBUG(dbgs() << "SUCCESS matched FI\n");
return true;
}
if (AM.hasIndexReg()) {
LLVM_DEBUG(dbgs() << "REJECT: Cannot match Index\n");
return false;
}
if (!AM.hasBaseReg()) {
LLVM_DEBUG(dbgs() << "REJECT: No Base reg\n");
return false;
}
Base = AM.BaseReg;
if (getSymbolicDisplacement(AM, SDLoc(N), Disp)) {
assert(!AM.Disp && "Should not be any displacement");
LLVM_DEBUG(dbgs() << "SUCCESS, matched Symbol\n");
return true;
}
// Give a chance to AddrType::ARI
if (AM.Disp == 0) {
LLVM_DEBUG(dbgs() << "REJECT: No displacement\n");
return false;
}
Disp = getI16Imm(AM.Disp, SDLoc(N));
LLVM_DEBUG(dbgs() << "SUCCESS\n");
return true;
}
static bool isAddressBase(const SDValue &N) {
switch (N.getOpcode()) {
case ISD::ADD:
case ISD::ADDC:
return llvm::any_of(N.getNode()->ops(),
[](const SDUse &U) { return isAddressBase(U.get()); });
case M68kISD::Wrapper:
case M68kISD::WrapperPC:
case M68kISD::GLOBAL_BASE_REG:
return true;
default:
return false;
}
}
bool M68kDAGToDAGISel::SelectARII(SDNode *Parent, SDValue N, SDValue &Disp,
SDValue &Base, SDValue &Index) {
M68kISelAddressMode AM(M68kISelAddressMode::AddrType::ARII);
LLVM_DEBUG(dbgs() << "Selecting AddrType::ARII: ");
if (!matchAddress(N, AM))
return false;
if (AM.isPCRelative()) {
LLVM_DEBUG(dbgs() << "REJECT: PC relative\n");
return false;
}
if (!AM.hasIndexReg()) {
LLVM_DEBUG(dbgs() << "REJECT: No Index\n");
return false;
}
if (!AM.hasBaseReg()) {
LLVM_DEBUG(dbgs() << "REJECT: No Base\n");
return false;
}
if (!isAddressBase(AM.BaseReg) && isAddressBase(AM.IndexReg)) {
Base = AM.IndexReg;
Index = AM.BaseReg;
} else {
Base = AM.BaseReg;
Index = AM.IndexReg;
}
if (AM.hasSymbolicDisplacement()) {
LLVM_DEBUG(dbgs() << "REJECT, Cannot match symbolic displacement\n");
return false;
}
// The idea here is that we want to use AddrType::ARII without displacement
// only if necessary like memory operations, otherwise this must be lowered
// into addition
if (AM.Disp == 0 && (!Parent || (Parent->getOpcode() != ISD::LOAD &&
Parent->getOpcode() != ISD::STORE))) {
LLVM_DEBUG(dbgs() << "REJECT: Displacement is Zero\n");
return false;
}
Disp = getI8Imm(AM.Disp, SDLoc(N));
LLVM_DEBUG(dbgs() << "SUCCESS\n");
return true;
}
bool M68kDAGToDAGISel::SelectAL(SDNode *Parent, SDValue N, SDValue &Sym) {
LLVM_DEBUG(dbgs() << "Selecting AddrType::AL: ");
M68kISelAddressMode AM(M68kISelAddressMode::AddrType::AL);
if (!matchAddress(N, AM)) {
LLVM_DEBUG(dbgs() << "REJECT: Match failed\n");
return false;
}
if (AM.isPCRelative()) {
LLVM_DEBUG(dbgs() << "REJECT: Cannot match PC relative address\n");
return false;
}
if (AM.hasBase()) {
LLVM_DEBUG(dbgs() << "REJECT: Cannot match Base\n");
return false;
}
if (AM.hasIndexReg()) {
LLVM_DEBUG(dbgs() << "REJECT: Cannot match Index\n");
return false;
}
if (getSymbolicDisplacement(AM, SDLoc(N), Sym)) {
LLVM_DEBUG(dbgs() << "SUCCESS: Matched symbol\n");
return true;
}
if (AM.Disp) {
Sym = getI32Imm(AM.Disp, SDLoc(N));
LLVM_DEBUG(dbgs() << "SUCCESS\n");
return true;
}
LLVM_DEBUG(dbgs() << "REJECT: Not Symbol or Disp\n");
return false;
;
}
bool M68kDAGToDAGISel::SelectPCD(SDNode *Parent, SDValue N, SDValue &Disp) {
LLVM_DEBUG(dbgs() << "Selecting AddrType::PCD: ");
M68kISelAddressMode AM(M68kISelAddressMode::AddrType::PCD);
if (!matchAddress(N, AM))
return false;
if (!AM.isPCRelative()) {
LLVM_DEBUG(dbgs() << "REJECT: Not PC relative\n");
return false;
}
if (AM.hasIndexReg()) {
LLVM_DEBUG(dbgs() << "REJECT: Cannot match Index\n");
return false;
}
if (getSymbolicDisplacement(AM, SDLoc(N), Disp)) {
LLVM_DEBUG(dbgs() << "SUCCESS, matched Symbol\n");
return true;
}
Disp = getI16Imm(AM.Disp, SDLoc(N));
LLVM_DEBUG(dbgs() << "SUCCESS\n");
return true;
}
bool M68kDAGToDAGISel::SelectPCI(SDNode *Parent, SDValue N, SDValue &Disp,
SDValue &Index) {
LLVM_DEBUG(dbgs() << "Selecting AddrType::PCI: ");
M68kISelAddressMode AM(M68kISelAddressMode::AddrType::PCI);
if (!matchAddress(N, AM))
return false;
if (!AM.isPCRelative()) {
LLVM_DEBUG(dbgs() << "REJECT: Not PC relative\n");
return false;
}
if (!AM.hasIndexReg()) {
LLVM_DEBUG(dbgs() << "REJECT: No Index\n");
return false;
}
Index = AM.IndexReg;
if (getSymbolicDisplacement(AM, SDLoc(N), Disp)) {
assert(!AM.Disp && "Should not be any displacement");
LLVM_DEBUG(dbgs() << "SUCCESS, matched Symbol\n");
return true;
}
Disp = getI8Imm(AM.Disp, SDLoc(N));
LLVM_DEBUG(dbgs() << "SUCCESS\n");
return true;
}
bool M68kDAGToDAGISel::SelectARI(SDNode *Parent, SDValue N, SDValue &Base) {
LLVM_DEBUG(dbgs() << "Selecting AddrType::ARI: ");
M68kISelAddressMode AM(M68kISelAddressMode::AddrType::ARI);
if (!matchAddress(N, AM)) {
LLVM_DEBUG(dbgs() << "REJECT: Match failed\n");
return false;
}
if (AM.isPCRelative()) {
LLVM_DEBUG(dbgs() << "REJECT: Cannot match PC relative address\n");
return false;
}
// AddrType::ARI does not use these
if (AM.hasIndexReg() || AM.Disp != 0) {
LLVM_DEBUG(dbgs() << "REJECT: Cannot match Index or Disp\n");
return false;
}
// Must be matched by AddrType::AL
if (AM.hasSymbolicDisplacement()) {
LLVM_DEBUG(dbgs() << "REJECT: Cannot match Symbolic Disp\n");
return false;
}
if (AM.hasBaseReg()) {
Base = AM.BaseReg;
LLVM_DEBUG(dbgs() << "SUCCESS\n");
return true;
}
return false;
}
bool M68kDAGToDAGISel::SelectInlineAsmMemoryOperand(
const SDValue &Op, InlineAsm::ConstraintCode ConstraintID,
std::vector<SDValue> &OutOps) {
// In order to tell AsmPrinter the exact addressing mode we select here, which
// might comprise of multiple SDValues (hence MachineOperands), a 32-bit
// immediate value is prepended to the list of selected SDValues to indicate
// the addressing mode kind.
using AMK = M68k::MemAddrModeKind;
auto addKind = [this](SDValue &Opnd, AMK Kind) -> bool {
Opnd = CurDAG->getTargetConstant(unsigned(Kind), SDLoc(), MVT::i32);
return true;
};
switch (ConstraintID) {
// Generic memory operand.
case InlineAsm::ConstraintCode::m: {
// Try every supported (memory) addressing modes.
SDValue Operands[4];
// TODO: The ordering of the following SelectXXX is relatively...arbitrary,
// right now we simply sort them by descending complexity. Maybe we should
// adjust this by code model and/or relocation mode in the future.
if (SelectARII(nullptr, Op, Operands[1], Operands[2], Operands[3]) &&
addKind(Operands[0], AMK::f)) {
OutOps.insert(OutOps.end(), &Operands[0], Operands + 4);
return false;
}
if ((SelectPCI(nullptr, Op, Operands[1], Operands[2]) &&
addKind(Operands[0], AMK::k)) ||
(SelectARID(nullptr, Op, Operands[1], Operands[2]) &&
addKind(Operands[0], AMK::p))) {
OutOps.insert(OutOps.end(), &Operands[0], Operands + 3);
return false;
}
if ((SelectPCD(nullptr, Op, Operands[1]) && addKind(Operands[0], AMK::q)) ||
(SelectARI(nullptr, Op, Operands[1]) && addKind(Operands[0], AMK::j)) ||
(SelectAL(nullptr, Op, Operands[1]) && addKind(Operands[0], AMK::b))) {
OutOps.insert(OutOps.end(), {Operands[0], Operands[1]});
return false;
}
return true;
}
// 'Q': Address register indirect addressing.
case InlineAsm::ConstraintCode::Q: {
SDValue AMKind, Base;
// 'j' addressing mode.
// TODO: Add support for 'o' and 'e' after their
// select functions are implemented.
if (SelectARI(nullptr, Op, Base) && addKind(AMKind, AMK::j)) {
OutOps.insert(OutOps.end(), {AMKind, Base});
return false;
}
return true;
}
// 'U': Address register indirect w/ constant offset addressing.
case InlineAsm::ConstraintCode::Um: {
SDValue AMKind, Base, Offset;
// 'p' addressing mode.
if (SelectARID(nullptr, Op, Offset, Base) && addKind(AMKind, AMK::p)) {
OutOps.insert(OutOps.end(), {AMKind, Offset, Base});
return false;
}
return true;
}
default:
return true;
}
}
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