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//===---- AVRAsmParser.cpp - Parse AVR assembly to MCInst instructions ----===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "AVR.h"
#include "AVRRegisterInfo.h"
#include "MCTargetDesc/AVRMCELFStreamer.h"
#include "MCTargetDesc/AVRMCExpr.h"
#include "MCTargetDesc/AVRMCTargetDesc.h"
#include "TargetInfo/AVRTargetInfo.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstBuilder.h"
#include "llvm/MC/MCParser/MCAsmLexer.h"
#include "llvm/MC/MCParser/MCParsedAsmOperand.h"
#include "llvm/MC/MCParser/MCTargetAsmParser.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCValue.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/TargetRegistry.h"
#include <sstream>
#define DEBUG_TYPE "avr-asm-parser"
using namespace llvm;
namespace {
/// Parses AVR assembly from a stream.
class AVRAsmParser : public MCTargetAsmParser {
const MCSubtargetInfo &STI;
MCAsmParser &Parser;
const MCRegisterInfo *MRI;
const std::string GENERATE_STUBS = "gs";
#define GET_ASSEMBLER_HEADER
#include "AVRGenAsmMatcher.inc"
bool MatchAndEmitInstruction(SMLoc IDLoc, unsigned &Opcode,
OperandVector &Operands, MCStreamer &Out,
uint64_t &ErrorInfo,
bool MatchingInlineAsm) override;
bool ParseRegister(unsigned &RegNo, SMLoc &StartLoc, SMLoc &EndLoc) override;
OperandMatchResultTy tryParseRegister(unsigned &RegNo, SMLoc &StartLoc,
SMLoc &EndLoc) override;
bool ParseInstruction(ParseInstructionInfo &Info, StringRef Name,
SMLoc NameLoc, OperandVector &Operands) override;
bool ParseDirective(AsmToken DirectiveID) override;
OperandMatchResultTy parseMemriOperand(OperandVector &Operands);
bool parseOperand(OperandVector &Operands);
int parseRegisterName(unsigned (*matchFn)(StringRef));
int parseRegisterName();
int parseRegister(bool RestoreOnFailure = false);
bool tryParseRegisterOperand(OperandVector &Operands);
bool tryParseExpression(OperandVector &Operands);
bool tryParseRelocExpression(OperandVector &Operands);
void eatComma();
unsigned validateTargetOperandClass(MCParsedAsmOperand &Op,
unsigned Kind) override;
unsigned toDREG(unsigned Reg, unsigned From = AVR::sub_lo) {
MCRegisterClass const *Class = &AVRMCRegisterClasses[AVR::DREGSRegClassID];
return MRI->getMatchingSuperReg(Reg, From, Class);
}
bool emit(MCInst &Instruction, SMLoc const &Loc, MCStreamer &Out) const;
bool invalidOperand(SMLoc const &Loc, OperandVector const &Operands,
uint64_t const &ErrorInfo);
bool missingFeature(SMLoc const &Loc, uint64_t const &ErrorInfo);
bool parseLiteralValues(unsigned SizeInBytes, SMLoc L);
public:
AVRAsmParser(const MCSubtargetInfo &STI, MCAsmParser &Parser,
const MCInstrInfo &MII, const MCTargetOptions &Options)
: MCTargetAsmParser(Options, STI, MII), STI(STI), Parser(Parser) {
MCAsmParserExtension::Initialize(Parser);
MRI = getContext().getRegisterInfo();
setAvailableFeatures(ComputeAvailableFeatures(STI.getFeatureBits()));
}
MCAsmParser &getParser() const { return Parser; }
MCAsmLexer &getLexer() const { return Parser.getLexer(); }
};
/// An parsed AVR assembly operand.
class AVROperand : public MCParsedAsmOperand {
typedef MCParsedAsmOperand Base;
enum KindTy { k_Immediate, k_Register, k_Token, k_Memri } Kind;
public:
AVROperand(StringRef Tok, SMLoc const &S)
: Base(), Kind(k_Token), Tok(Tok), Start(S), End(S) {}
AVROperand(unsigned Reg, SMLoc const &S, SMLoc const &E)
: Base(), Kind(k_Register), RegImm({Reg, nullptr}), Start(S), End(E) {}
AVROperand(MCExpr const *Imm, SMLoc const &S, SMLoc const &E)
: Base(), Kind(k_Immediate), RegImm({0, Imm}), Start(S), End(E) {}
AVROperand(unsigned Reg, MCExpr const *Imm, SMLoc const &S, SMLoc const &E)
: Base(), Kind(k_Memri), RegImm({Reg, Imm}), Start(S), End(E) {}
struct RegisterImmediate {
unsigned Reg;
MCExpr const *Imm;
};
union {
StringRef Tok;
RegisterImmediate RegImm;
};
SMLoc Start, End;
public:
void addRegOperands(MCInst &Inst, unsigned N) const {
assert(Kind == k_Register && "Unexpected operand kind");
assert(N == 1 && "Invalid number of operands!");
Inst.addOperand(MCOperand::createReg(getReg()));
}
void addExpr(MCInst &Inst, const MCExpr *Expr) const {
// Add as immediate when possible
if (!Expr)
Inst.addOperand(MCOperand::createImm(0));
else if (const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(Expr))
Inst.addOperand(MCOperand::createImm(CE->getValue()));
else
Inst.addOperand(MCOperand::createExpr(Expr));
}
void addImmOperands(MCInst &Inst, unsigned N) const {
assert(Kind == k_Immediate && "Unexpected operand kind");
assert(N == 1 && "Invalid number of operands!");
const MCExpr *Expr = getImm();
addExpr(Inst, Expr);
}
/// Adds the contained reg+imm operand to an instruction.
void addMemriOperands(MCInst &Inst, unsigned N) const {
assert(Kind == k_Memri && "Unexpected operand kind");
assert(N == 2 && "Invalid number of operands");
Inst.addOperand(MCOperand::createReg(getReg()));
addExpr(Inst, getImm());
}
void addImmCom8Operands(MCInst &Inst, unsigned N) const {
assert(N == 1 && "Invalid number of operands!");
// The operand is actually a imm8, but we have its bitwise
// negation in the assembly source, so twiddle it here.
const auto *CE = cast<MCConstantExpr>(getImm());
Inst.addOperand(MCOperand::createImm(~(uint8_t)CE->getValue()));
}
bool isImmCom8() const {
if (!isImm()) return false;
const auto *CE = dyn_cast<MCConstantExpr>(getImm());
if (!CE) return false;
int64_t Value = CE->getValue();
return isUInt<8>(Value);
}
bool isReg() const override { return Kind == k_Register; }
bool isImm() const override { return Kind == k_Immediate; }
bool isToken() const override { return Kind == k_Token; }
bool isMem() const override { return Kind == k_Memri; }
bool isMemri() const { return Kind == k_Memri; }
StringRef getToken() const {
assert(Kind == k_Token && "Invalid access!");
return Tok;
}
unsigned getReg() const override {
assert((Kind == k_Register || Kind == k_Memri) && "Invalid access!");
return RegImm.Reg;
}
const MCExpr *getImm() const {
assert((Kind == k_Immediate || Kind == k_Memri) && "Invalid access!");
return RegImm.Imm;
}
static std::unique_ptr<AVROperand> CreateToken(StringRef Str, SMLoc S) {
return std::make_unique<AVROperand>(Str, S);
}
static std::unique_ptr<AVROperand> CreateReg(unsigned RegNum, SMLoc S,
SMLoc E) {
return std::make_unique<AVROperand>(RegNum, S, E);
}
static std::unique_ptr<AVROperand> CreateImm(const MCExpr *Val, SMLoc S,
SMLoc E) {
return std::make_unique<AVROperand>(Val, S, E);
}
static std::unique_ptr<AVROperand>
CreateMemri(unsigned RegNum, const MCExpr *Val, SMLoc S, SMLoc E) {
return std::make_unique<AVROperand>(RegNum, Val, S, E);
}
void makeToken(StringRef Token) {
Kind = k_Token;
Tok = Token;
}
void makeReg(unsigned RegNo) {
Kind = k_Register;
RegImm = {RegNo, nullptr};
}
void makeImm(MCExpr const *Ex) {
Kind = k_Immediate;
RegImm = {0, Ex};
}
void makeMemri(unsigned RegNo, MCExpr const *Imm) {
Kind = k_Memri;
RegImm = {RegNo, Imm};
}
SMLoc getStartLoc() const override { return Start; }
SMLoc getEndLoc() const override { return End; }
void print(raw_ostream &O) const override {
switch (Kind) {
case k_Token:
O << "Token: \"" << getToken() << "\"";
break;
case k_Register:
O << "Register: " << getReg();
break;
case k_Immediate:
O << "Immediate: \"" << *getImm() << "\"";
break;
case k_Memri: {
// only manually print the size for non-negative values,
// as the sign is inserted automatically.
O << "Memri: \"" << getReg() << '+' << *getImm() << "\"";
break;
}
}
O << "\n";
}
};
} // end anonymous namespace.
// Auto-generated Match Functions
/// Maps from the set of all register names to a register number.
/// \note Generated by TableGen.
static unsigned MatchRegisterName(StringRef Name);
/// Maps from the set of all alternative registernames to a register number.
/// \note Generated by TableGen.
static unsigned MatchRegisterAltName(StringRef Name);
bool AVRAsmParser::invalidOperand(SMLoc const &Loc,
OperandVector const &Operands,
uint64_t const &ErrorInfo) {
SMLoc ErrorLoc = Loc;
char const *Diag = 0;
if (ErrorInfo != ~0U) {
if (ErrorInfo >= Operands.size()) {
Diag = "too few operands for instruction.";
} else {
AVROperand const &Op = (AVROperand const &)*Operands[ErrorInfo];
// TODO: See if we can do a better error than just "invalid ...".
if (Op.getStartLoc() != SMLoc()) {
ErrorLoc = Op.getStartLoc();
}
}
}
if (!Diag) {
Diag = "invalid operand for instruction";
}
return Error(ErrorLoc, Diag);
}
bool AVRAsmParser::missingFeature(llvm::SMLoc const &Loc,
uint64_t const &ErrorInfo) {
return Error(Loc, "instruction requires a CPU feature not currently enabled");
}
bool AVRAsmParser::emit(MCInst &Inst, SMLoc const &Loc, MCStreamer &Out) const {
Inst.setLoc(Loc);
Out.emitInstruction(Inst, STI);
return false;
}
bool AVRAsmParser::MatchAndEmitInstruction(SMLoc Loc, unsigned &Opcode,
OperandVector &Operands,
MCStreamer &Out, uint64_t &ErrorInfo,
bool MatchingInlineAsm) {
MCInst Inst;
unsigned MatchResult =
MatchInstructionImpl(Operands, Inst, ErrorInfo, MatchingInlineAsm);
switch (MatchResult) {
case Match_Success: return emit(Inst, Loc, Out);
case Match_MissingFeature: return missingFeature(Loc, ErrorInfo);
case Match_InvalidOperand: return invalidOperand(Loc, Operands, ErrorInfo);
case Match_MnemonicFail: return Error(Loc, "invalid instruction");
default: return true;
}
}
/// Parses a register name using a given matching function.
/// Checks for lowercase or uppercase if necessary.
int AVRAsmParser::parseRegisterName(unsigned (*matchFn)(StringRef)) {
StringRef Name = Parser.getTok().getString();
int RegNum = matchFn(Name);
// GCC supports case insensitive register names. Some of the AVR registers
// are all lower case, some are all upper case but non are mixed. We prefer
// to use the original names in the register definitions. That is why we
// have to test both upper and lower case here.
if (RegNum == AVR::NoRegister) {
RegNum = matchFn(Name.lower());
}
if (RegNum == AVR::NoRegister) {
RegNum = matchFn(Name.upper());
}
return RegNum;
}
int AVRAsmParser::parseRegisterName() {
int RegNum = parseRegisterName(&MatchRegisterName);
if (RegNum == AVR::NoRegister)
RegNum = parseRegisterName(&MatchRegisterAltName);
return RegNum;
}
int AVRAsmParser::parseRegister(bool RestoreOnFailure) {
int RegNum = AVR::NoRegister;
if (Parser.getTok().is(AsmToken::Identifier)) {
// Check for register pair syntax
if (Parser.getLexer().peekTok().is(AsmToken::Colon)) {
AsmToken HighTok = Parser.getTok();
Parser.Lex();
AsmToken ColonTok = Parser.getTok();
Parser.Lex(); // Eat high (odd) register and colon
if (Parser.getTok().is(AsmToken::Identifier)) {
// Convert lower (even) register to DREG
RegNum = toDREG(parseRegisterName());
}
if (RegNum == AVR::NoRegister && RestoreOnFailure) {
getLexer().UnLex(std::move(ColonTok));
getLexer().UnLex(std::move(HighTok));
}
} else {
RegNum = parseRegisterName();
}
}
return RegNum;
}
bool AVRAsmParser::tryParseRegisterOperand(OperandVector &Operands) {
int RegNo = parseRegister();
if (RegNo == AVR::NoRegister)
return true;
AsmToken const &T = Parser.getTok();
Operands.push_back(AVROperand::CreateReg(RegNo, T.getLoc(), T.getEndLoc()));
Parser.Lex(); // Eat register token.
return false;
}
bool AVRAsmParser::tryParseExpression(OperandVector &Operands) {
SMLoc S = Parser.getTok().getLoc();
if (!tryParseRelocExpression(Operands))
return false;
if ((Parser.getTok().getKind() == AsmToken::Plus ||
Parser.getTok().getKind() == AsmToken::Minus) &&
Parser.getLexer().peekTok().getKind() == AsmToken::Identifier) {
// Don't handle this case - it should be split into two
// separate tokens.
return true;
}
// Parse (potentially inner) expression
MCExpr const *Expression;
if (getParser().parseExpression(Expression))
return true;
SMLoc E = SMLoc::getFromPointer(Parser.getTok().getLoc().getPointer() - 1);
Operands.push_back(AVROperand::CreateImm(Expression, S, E));
return false;
}
bool AVRAsmParser::tryParseRelocExpression(OperandVector &Operands) {
bool isNegated = false;
AVRMCExpr::VariantKind ModifierKind = AVRMCExpr::VK_AVR_None;
SMLoc S = Parser.getTok().getLoc();
// Check for sign
AsmToken tokens[2];
size_t ReadCount = Parser.getLexer().peekTokens(tokens);
if (ReadCount == 2) {
if ((tokens[0].getKind() == AsmToken::Identifier &&
tokens[1].getKind() == AsmToken::LParen) ||
(tokens[0].getKind() == AsmToken::LParen &&
tokens[1].getKind() == AsmToken::Minus)) {
AsmToken::TokenKind CurTok = Parser.getLexer().getKind();
if (CurTok == AsmToken::Minus ||
tokens[1].getKind() == AsmToken::Minus) {
isNegated = true;
} else {
assert(CurTok == AsmToken::Plus);
isNegated = false;
}
// Eat the sign
if (CurTok == AsmToken::Minus || CurTok == AsmToken::Plus)
Parser.Lex();
}
}
// Check if we have a target specific modifier (lo8, hi8, &c)
if (Parser.getTok().getKind() != AsmToken::Identifier ||
Parser.getLexer().peekTok().getKind() != AsmToken::LParen) {
// Not a reloc expr
return true;
}
StringRef ModifierName = Parser.getTok().getString();
ModifierKind = AVRMCExpr::getKindByName(ModifierName.str().c_str());
if (ModifierKind != AVRMCExpr::VK_AVR_None) {
Parser.Lex();
Parser.Lex(); // Eat modifier name and parenthesis
if (Parser.getTok().getString() == GENERATE_STUBS &&
Parser.getTok().getKind() == AsmToken::Identifier) {
std::string GSModName = ModifierName.str() + "_" + GENERATE_STUBS;
ModifierKind = AVRMCExpr::getKindByName(GSModName.c_str());
if (ModifierKind != AVRMCExpr::VK_AVR_None)
Parser.Lex(); // Eat gs modifier name
}
} else {
return Error(Parser.getTok().getLoc(), "unknown modifier");
}
if (tokens[1].getKind() == AsmToken::Minus ||
tokens[1].getKind() == AsmToken::Plus) {
Parser.Lex();
assert(Parser.getTok().getKind() == AsmToken::LParen);
Parser.Lex(); // Eat the sign and parenthesis
}
MCExpr const *InnerExpression;
if (getParser().parseExpression(InnerExpression))
return true;
if (tokens[1].getKind() == AsmToken::Minus ||
tokens[1].getKind() == AsmToken::Plus) {
assert(Parser.getTok().getKind() == AsmToken::RParen);
Parser.Lex(); // Eat closing parenthesis
}
// If we have a modifier wrap the inner expression
assert(Parser.getTok().getKind() == AsmToken::RParen);
Parser.Lex(); // Eat closing parenthesis
MCExpr const *Expression = AVRMCExpr::create(ModifierKind, InnerExpression,
isNegated, getContext());
SMLoc E = SMLoc::getFromPointer(Parser.getTok().getLoc().getPointer() - 1);
Operands.push_back(AVROperand::CreateImm(Expression, S, E));
return false;
}
bool AVRAsmParser::parseOperand(OperandVector &Operands) {
LLVM_DEBUG(dbgs() << "parseOperand\n");
switch (getLexer().getKind()) {
default:
return Error(Parser.getTok().getLoc(), "unexpected token in operand");
case AsmToken::Identifier:
// Try to parse a register, if it fails,
// fall through to the next case.
if (!tryParseRegisterOperand(Operands)) {
return false;
}
LLVM_FALLTHROUGH;
case AsmToken::LParen:
case AsmToken::Integer:
case AsmToken::Dot:
return tryParseExpression(Operands);
case AsmToken::Plus:
case AsmToken::Minus: {
// If the sign preceeds a number, parse the number,
// otherwise treat the sign a an independent token.
switch (getLexer().peekTok().getKind()) {
case AsmToken::Integer:
case AsmToken::BigNum:
case AsmToken::Identifier:
case AsmToken::Real:
if (!tryParseExpression(Operands))
return false;
break;
default:
break;
}
// Treat the token as an independent token.
Operands.push_back(AVROperand::CreateToken(Parser.getTok().getString(),
Parser.getTok().getLoc()));
Parser.Lex(); // Eat the token.
return false;
}
}
// Could not parse operand
return true;
}
OperandMatchResultTy
AVRAsmParser::parseMemriOperand(OperandVector &Operands) {
LLVM_DEBUG(dbgs() << "parseMemriOperand()\n");
SMLoc E, S;
MCExpr const *Expression;
int RegNo;
// Parse register.
{
RegNo = parseRegister();
if (RegNo == AVR::NoRegister)
return MatchOperand_ParseFail;
S = SMLoc::getFromPointer(Parser.getTok().getLoc().getPointer() - 1);
Parser.Lex(); // Eat register token.
}
// Parse immediate;
{
if (getParser().parseExpression(Expression))
return MatchOperand_ParseFail;
E = SMLoc::getFromPointer(Parser.getTok().getLoc().getPointer() - 1);
}
Operands.push_back(AVROperand::CreateMemri(RegNo, Expression, S, E));
return MatchOperand_Success;
}
bool AVRAsmParser::ParseRegister(unsigned &RegNo, SMLoc &StartLoc,
SMLoc &EndLoc) {
StartLoc = Parser.getTok().getLoc();
RegNo = parseRegister(/*RestoreOnFailure=*/false);
EndLoc = Parser.getTok().getLoc();
return (RegNo == AVR::NoRegister);
}
OperandMatchResultTy AVRAsmParser::tryParseRegister(unsigned &RegNo,
SMLoc &StartLoc,
SMLoc &EndLoc) {
StartLoc = Parser.getTok().getLoc();
RegNo = parseRegister(/*RestoreOnFailure=*/true);
EndLoc = Parser.getTok().getLoc();
if (RegNo == AVR::NoRegister)
return MatchOperand_NoMatch;
return MatchOperand_Success;
}
void AVRAsmParser::eatComma() {
if (getLexer().is(AsmToken::Comma)) {
Parser.Lex();
} else {
// GCC allows commas to be omitted.
}
}
bool AVRAsmParser::ParseInstruction(ParseInstructionInfo &Info,
StringRef Mnemonic, SMLoc NameLoc,
OperandVector &Operands) {
Operands.push_back(AVROperand::CreateToken(Mnemonic, NameLoc));
bool first = true;
while (getLexer().isNot(AsmToken::EndOfStatement)) {
if (!first) eatComma();
first = false;
auto MatchResult = MatchOperandParserImpl(Operands, Mnemonic);
if (MatchResult == MatchOperand_Success) {
continue;
}
if (MatchResult == MatchOperand_ParseFail) {
SMLoc Loc = getLexer().getLoc();
Parser.eatToEndOfStatement();
return Error(Loc, "failed to parse register and immediate pair");
}
if (parseOperand(Operands)) {
SMLoc Loc = getLexer().getLoc();
Parser.eatToEndOfStatement();
return Error(Loc, "unexpected token in argument list");
}
}
Parser.Lex(); // Consume the EndOfStatement
return false;
}
bool AVRAsmParser::ParseDirective(llvm::AsmToken DirectiveID) {
StringRef IDVal = DirectiveID.getIdentifier();
if (IDVal.lower() == ".long") {
parseLiteralValues(SIZE_LONG, DirectiveID.getLoc());
} else if (IDVal.lower() == ".word" || IDVal.lower() == ".short") {
parseLiteralValues(SIZE_WORD, DirectiveID.getLoc());
} else if (IDVal.lower() == ".byte") {
parseLiteralValues(1, DirectiveID.getLoc());
}
return true;
}
bool AVRAsmParser::parseLiteralValues(unsigned SizeInBytes, SMLoc L) {
MCAsmParser &Parser = getParser();
AVRMCELFStreamer &AVRStreamer =
static_cast<AVRMCELFStreamer &>(Parser.getStreamer());
AsmToken Tokens[2];
size_t ReadCount = Parser.getLexer().peekTokens(Tokens);
if (ReadCount == 2 && Parser.getTok().getKind() == AsmToken::Identifier &&
Tokens[0].getKind() == AsmToken::Minus &&
Tokens[1].getKind() == AsmToken::Identifier) {
MCSymbol *Symbol = getContext().getOrCreateSymbol(".text");
AVRStreamer.emitValueForModiferKind(Symbol, SizeInBytes, L,
AVRMCExpr::VK_AVR_None);
return false;
}
if (Parser.getTok().getKind() == AsmToken::Identifier &&
Parser.getLexer().peekTok().getKind() == AsmToken::LParen) {
StringRef ModifierName = Parser.getTok().getString();
AVRMCExpr::VariantKind ModifierKind =
AVRMCExpr::getKindByName(ModifierName.str().c_str());
if (ModifierKind != AVRMCExpr::VK_AVR_None) {
Parser.Lex();
Parser.Lex(); // Eat the modifier and parenthesis
} else {
return Error(Parser.getTok().getLoc(), "unknown modifier");
}
MCSymbol *Symbol =
getContext().getOrCreateSymbol(Parser.getTok().getString());
AVRStreamer.emitValueForModiferKind(Symbol, SizeInBytes, L, ModifierKind);
return false;
}
auto parseOne = [&]() -> bool {
const MCExpr *Value;
if (Parser.parseExpression(Value))
return true;
Parser.getStreamer().emitValue(Value, SizeInBytes, L);
return false;
};
return (parseMany(parseOne));
}
extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeAVRAsmParser() {
RegisterMCAsmParser<AVRAsmParser> X(getTheAVRTarget());
}
#define GET_REGISTER_MATCHER
#define GET_MATCHER_IMPLEMENTATION
#include "AVRGenAsmMatcher.inc"
// Uses enums defined in AVRGenAsmMatcher.inc
unsigned AVRAsmParser::validateTargetOperandClass(MCParsedAsmOperand &AsmOp,
unsigned ExpectedKind) {
AVROperand &Op = static_cast<AVROperand &>(AsmOp);
MatchClassKind Expected = static_cast<MatchClassKind>(ExpectedKind);
// If need be, GCC converts bare numbers to register names
// It's ugly, but GCC supports it.
if (Op.isImm()) {
if (MCConstantExpr const *Const = dyn_cast<MCConstantExpr>(Op.getImm())) {
int64_t RegNum = Const->getValue();
std::ostringstream RegName;
RegName << "r" << RegNum;
RegNum = MatchRegisterName(RegName.str().c_str());
if (RegNum != AVR::NoRegister) {
Op.makeReg(RegNum);
if (validateOperandClass(Op, Expected) == Match_Success) {
return Match_Success;
}
}
// Let the other quirks try their magic.
}
}
if (Op.isReg()) {
// If the instruction uses a register pair but we got a single, lower
// register we perform a "class cast".
if (isSubclass(Expected, MCK_DREGS)) {
unsigned correspondingDREG = toDREG(Op.getReg());
if (correspondingDREG != AVR::NoRegister) {
Op.makeReg(correspondingDREG);
return validateOperandClass(Op, Expected);
}
}
}
return Match_InvalidOperand;
}