1//===- VarLenCodeEmitterGen.h - CEG for variable-length insts ---*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file declare the CodeEmitterGen component for variable-length
10// instructions. See the .cpp file for more details.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_UTILS_TABLEGEN_COMMON_VARLENCODEEMITTERGEN_H
15#define LLVM_UTILS_TABLEGEN_COMMON_VARLENCODEEMITTERGEN_H
16
17#include "llvm/TableGen/Record.h"
18
19namespace llvm {
20
21struct EncodingSegment {
22 unsigned BitWidth;
23 const Init *Value;
24 StringRef CustomEncoder = "";
25 StringRef CustomDecoder = "";
26};
27
28class VarLenInst {
29 const RecordVal *TheDef;
30 size_t NumBits;
31
32 // Set if any of the segment is not fixed value.
33 bool HasDynamicSegment;
34
35 SmallVector<EncodingSegment, 4> Segments;
36
37 void buildRec(const DagInit *DI);
38
39public:
40 VarLenInst() : TheDef(nullptr), NumBits(0U), HasDynamicSegment(false) {}
41
42 explicit VarLenInst(const DagInit *DI, const RecordVal *TheDef);
43
44 /// Number of bits
45 size_t size() const { return NumBits; }
46
47 using const_iterator = decltype(Segments)::const_iterator;
48
49 const_iterator begin() const { return Segments.begin(); }
50 const_iterator end() const { return Segments.end(); }
51 size_t getNumSegments() const { return Segments.size(); }
52
53 bool isFixedValueOnly() const { return !HasDynamicSegment; }
54};
55
56void emitVarLenCodeEmitter(const RecordKeeper &R, raw_ostream &OS);
57
58} // end namespace llvm
59
60#endif // LLVM_UTILS_TABLEGEN_COMMON_VARLENCODEEMITTERGEN_H
61