/// Emit a dwarf register operation for describing
/// - a small value occupying only part of a register or
/// - a small register representing only part of a value.
static void emitDwarfOpPiece(ByteStreamer &Streamer, unsigned Size,
unsigned Offset) {
assert(Size > 0);
if (Offset > 0) {
Streamer.EmitInt8(dwarf::DW_OP_bit_piece, "DW_OP_bit_piece");
Streamer.EmitULEB128(Size, Twine(Size));
Streamer.EmitULEB128(Offset, Twine(Offset));
} else {
Streamer.EmitInt8(dwarf::DW_OP_piece, "DW_OP_piece");
unsigned ByteSize = Size / 8; // Assuming 8 bits per byte.
Streamer.EmitULEB128(ByteSize, Twine(ByteSize));
}
}
void AsmPrinter::EmitDwarfOpPiece(ByteStreamer &Streamer, unsigned SizeInBits,
unsigned OffsetInBits) const {
assert(SizeInBits > 0 && "piece has size zero");
const unsigned SizeOfByte = 8;
if (OffsetInBits > 0 || SizeInBits % SizeOfByte) {
Streamer.EmitInt8(dwarf::DW_OP_bit_piece, "DW_OP_bit_piece");
Streamer.EmitULEB128(SizeInBits, Twine(SizeInBits));
Streamer.EmitULEB128(OffsetInBits, Twine(OffsetInBits));
} else {
Streamer.EmitInt8(dwarf::DW_OP_piece, "DW_OP_piece");
unsigned ByteSize = SizeInBits / SizeOfByte;
Streamer.EmitULEB128(ByteSize, Twine(ByteSize));
}
}
/// Emit a dwarf register operation.
static void emitDwarfRegOp(ByteStreamer &Streamer, int Reg) {
assert(Reg >= 0);
if (Reg < 32) {
Streamer.EmitInt8(dwarf::DW_OP_reg0 + Reg,
dwarf::OperationEncodingString(dwarf::DW_OP_reg0 + Reg));
} else {
Streamer.EmitInt8(dwarf::DW_OP_regx, "DW_OP_regx");
Streamer.EmitULEB128(Reg, Twine(Reg));
}
}
/// Emit an (double-)indirect dwarf register operation.
static void emitDwarfRegOpIndirect(ByteStreamer &Streamer, int Reg, int Offset,
bool Deref) {
assert(Reg >= 0);
if (Reg < 32) {
Streamer.EmitInt8(dwarf::DW_OP_breg0 + Reg,
dwarf::OperationEncodingString(dwarf::DW_OP_breg0 + Reg));
} else {
Streamer.EmitInt8(dwarf::DW_OP_bregx, "DW_OP_bregx");
Streamer.EmitULEB128(Reg, Twine(Reg));
}
Streamer.EmitSLEB128(Offset);
if (Deref)
Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
}
/// Emit a shift-right dwarf expression.
static void emitDwarfOpShr(ByteStreamer &Streamer,
unsigned ShiftBy) {
Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
Streamer.EmitULEB128(ShiftBy);
Streamer.EmitInt8(dwarf::DW_OP_shr, "DW_OP_shr");
}