| //===--------------------- CodeEmitter.h ------------------------*- 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 |
| /// |
| /// A utility class used to compute instruction encodings. It buffers encodings |
| /// for later usage. It exposes a simple API to compute and get the encodings as |
| /// StringRef. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_MCA_CODEEMITTER_H |
| #define LLVM_MCA_CODEEMITTER_H |
| |
| #include "llvm/ADT/ArrayRef.h" |
| #include "llvm/ADT/StringRef.h" |
| #include "llvm/MC/MCAsmBackend.h" |
| #include "llvm/MC/MCCodeEmitter.h" |
| #include "llvm/MC/MCFixup.h" |
| #include "llvm/MC/MCInst.h" |
| #include "llvm/MC/MCSubtargetInfo.h" |
| #include "llvm/MCA/Instruction.h" |
| #include "llvm/MCA/Support.h" |
| #include "llvm/Support/raw_ostream.h" |
| |
| #include <string> |
| |
| namespace llvm { |
| namespace mca { |
| |
| /// A utility class used to compute instruction encodings for a code region. |
| /// |
| /// It provides a simple API to compute and return instruction encodings as |
| /// strings. Encodings are cached internally for later usage. |
| class CodeEmitter { |
| const MCSubtargetInfo &STI; |
| const MCAsmBackend &MAB; |
| const MCCodeEmitter &MCE; |
| |
| SmallString<256> Code; |
| raw_svector_ostream VecOS; |
| ArrayRef<MCInst> Sequence; |
| |
| // An EncodingInfo pair stores <base, length> information. Base (i.e. first) |
| // is an index to the `Code`. Length (i.e. second) is the encoding size. |
| using EncodingInfo = std::pair<unsigned, unsigned>; |
| |
| // A cache of encodings. |
| SmallVector<EncodingInfo, 16> Encodings; |
| |
| EncodingInfo getOrCreateEncodingInfo(unsigned MCID); |
| |
| public: |
| CodeEmitter(const MCSubtargetInfo &ST, const MCAsmBackend &AB, |
| const MCCodeEmitter &CE, ArrayRef<MCInst> S) |
| : STI(ST), MAB(AB), MCE(CE), VecOS(Code), Sequence(S), |
| Encodings(S.size()) {} |
| |
| StringRef getEncoding(unsigned MCID) { |
| EncodingInfo EI = getOrCreateEncodingInfo(MCID); |
| return StringRef(&Code[EI.first], EI.second); |
| } |
| }; |
| |
| } // namespace mca |
| } // namespace llvm |
| |
| #endif // LLVM_MCA_CODEEMITTER_H |