1 //===- AsmWriterInst.h - Classes encapsulating a printable inst -*- 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 // These classes implement a parser for assembly strings.  The parser splits
10 // the string into operands, which can be literal strings (the constant bits of
11 // the string), actual operands (i.e., operands from the MachineInstr), and
12 // dynamically-generated text, specified by raw C++ code.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_UTILS_TABLEGEN_ASMWRITERINST_H
17 #define LLVM_UTILS_TABLEGEN_ASMWRITERINST_H
18 
19 #include <string>
20 #include <vector>
21 
22 namespace llvm {
23   class CodeGenInstruction;
24 
25   struct AsmWriterOperand {
26     enum OpType {
27       // Output this text surrounded by quotes to the asm.
28       isLiteralTextOperand,
29       // This is the name of a routine to call to print the operand.
30       isMachineInstrOperand,
31       // Output this text verbatim to the asm writer.  It is code that
32       // will output some text to the asm.
33       isLiteralStatementOperand
34     } OperandType;
35 
36     /// MiOpNo - For isMachineInstrOperand, this is the operand number of the
37     /// machine instruction.
38     unsigned MIOpNo = 0;
39 
40     /// Str - For isLiteralTextOperand, this IS the literal text.  For
41     /// isMachineInstrOperand, this is the PrinterMethodName for the operand..
42     /// For isLiteralStatementOperand, this is the code to insert verbatim
43     /// into the asm writer.
44     std::string Str;
45 
46     /// MiModifier - For isMachineInstrOperand, this is the modifier string for
47     /// an operand, specified with syntax like ${opname:modifier}.
48     std::string MiModifier;
49 
50     bool PCRel = false;
51 
52     // To make VS STL happy
53     AsmWriterOperand(OpType op = isLiteralTextOperand):OperandType(op) {}
54 
55     AsmWriterOperand(const std::string &LitStr,
56                      OpType op = isLiteralTextOperand)
57     : OperandType(op), Str(LitStr) {}
58 
59     AsmWriterOperand(const std::string &Printer, unsigned _MIOpNo,
60                      const std::string &Modifier,
61                      OpType op = isMachineInstrOperand, bool PCRel = false)
62         : OperandType(op), MIOpNo(_MIOpNo), Str(Printer), MiModifier(Modifier),
63           PCRel(PCRel) {}
64 
65     bool operator!=(const AsmWriterOperand &Other) const {
66       if (OperandType != Other.OperandType || Str != Other.Str) return true;
67       if (OperandType == isMachineInstrOperand)
68         return MIOpNo != Other.MIOpNo || MiModifier != Other.MiModifier ||
69                PCRel != Other.PCRel;
70       return false;
71     }
72     bool operator==(const AsmWriterOperand &Other) const {
73       return !operator!=(Other);
74     }
75 
76     /// getCode - Return the code that prints this operand.
77     std::string getCode(bool PassSubtarget) const;
78   };
79 
80   class AsmWriterInst {
81   public:
82     std::vector<AsmWriterOperand> Operands;
83     const CodeGenInstruction *CGI;
84     unsigned CGIIndex;
85 
86     AsmWriterInst(const CodeGenInstruction &CGI, unsigned CGIIndex,
87                   unsigned Variant);
88 
89     /// MatchesAllButOneOp - If this instruction is exactly identical to the
90     /// specified instruction except for one differing operand, return the
91     /// differing operand number.  Otherwise return ~0.
92     unsigned MatchesAllButOneOp(const AsmWriterInst &Other) const;
93 
94   private:
95     void AddLiteralString(const std::string &Str) {
96       // If the last operand was already a literal text string, append this to
97       // it, otherwise add a new operand.
98       if (!Operands.empty() &&
99           Operands.back().OperandType == AsmWriterOperand::isLiteralTextOperand)
100         Operands.back().Str.append(Str);
101       else
102         Operands.push_back(AsmWriterOperand(Str));
103     }
104   };
105 }
106 
107 #endif
108