xref: /freebsd/contrib/llvm-project/llvm/include/llvm/MC/MCInstrInfo.h (revision 700637cbb5e582861067a11aaca4d053546871d2)
1 //===-- llvm/MC/MCInstrInfo.h - Target Instruction Info ---------*- 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 describes the target machine instruction set.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_MC_MCINSTRINFO_H
14 #define LLVM_MC_MCINSTRINFO_H
15 
16 #include "llvm/ADT/StringRef.h"
17 #include "llvm/MC/MCInstrDesc.h"
18 #include "llvm/Support/Compiler.h"
19 #include <cassert>
20 
21 namespace llvm {
22 
23 class MCSubtargetInfo;
24 
25 //---------------------------------------------------------------------------
26 /// Interface to description of machine instruction set.
27 class MCInstrInfo {
28 public:
29   using ComplexDeprecationPredicate = bool (*)(MCInst &,
30                                                const MCSubtargetInfo &,
31                                                std::string &);
32 
33 private:
34   const MCInstrDesc *LastDesc;      // Raw array to allow static init'n
35   const unsigned *InstrNameIndices; // Array for name indices in InstrNameData
36   const char *InstrNameData;        // Instruction name string pool
37   // Subtarget feature that an instruction is deprecated on, if any
38   // -1 implies this is not deprecated by any single feature. It may still be
39   // deprecated due to a "complex" reason, below.
40   const uint8_t *DeprecatedFeatures;
41   // A complex method to determine if a certain instruction is deprecated or
42   // not, and return the reason for deprecation.
43   const ComplexDeprecationPredicate *ComplexDeprecationInfos;
44   unsigned NumOpcodes;              // Number of entries in the desc array
45 
46 public:
47   /// Initialize MCInstrInfo, called by TableGen auto-generated routines.
48   /// *DO NOT USE*.
InitMCInstrInfo(const MCInstrDesc * D,const unsigned * NI,const char * ND,const uint8_t * DF,const ComplexDeprecationPredicate * CDI,unsigned NO)49   void InitMCInstrInfo(const MCInstrDesc *D, const unsigned *NI, const char *ND,
50                        const uint8_t *DF,
51                        const ComplexDeprecationPredicate *CDI, unsigned NO) {
52     LastDesc = D + NO - 1;
53     InstrNameIndices = NI;
54     InstrNameData = ND;
55     DeprecatedFeatures = DF;
56     ComplexDeprecationInfos = CDI;
57     NumOpcodes = NO;
58   }
59 
getNumOpcodes()60   unsigned getNumOpcodes() const { return NumOpcodes; }
61 
62   /// Return the machine instruction descriptor that corresponds to the
63   /// specified instruction opcode.
get(unsigned Opcode)64   const MCInstrDesc &get(unsigned Opcode) const {
65     assert(Opcode < NumOpcodes && "Invalid opcode!");
66     // The table is indexed backwards from the last entry.
67     return *(LastDesc - Opcode);
68   }
69 
70   /// Returns the name for the instructions with the given opcode.
getName(unsigned Opcode)71   StringRef getName(unsigned Opcode) const {
72     assert(Opcode < NumOpcodes && "Invalid opcode!");
73     return StringRef(&InstrNameData[InstrNameIndices[Opcode]]);
74   }
75 
76   /// Returns true if a certain instruction is deprecated and if so
77   /// returns the reason in \p Info.
78   LLVM_ABI bool getDeprecatedInfo(MCInst &MI, const MCSubtargetInfo &STI,
79                                   std::string &Info) const;
80 };
81 
82 } // End llvm namespace
83 
84 #endif
85