summaryrefslogtreecommitdiffstats
path: root/src/shader_recompiler/frontend/maxwell/control_flow.h
blob: 8179787b8754dc62576c9728310a589963bcf617 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
// Copyright 2021 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.

#pragma once

#include <compare>
#include <optional>
#include <span>
#include <string>
#include <vector>

#include <boost/container/small_vector.hpp>
#include <boost/intrusive/set.hpp>

#include "shader_recompiler/environment.h"
#include "shader_recompiler/frontend/ir/condition.h"
#include "shader_recompiler/frontend/maxwell/instruction.h"
#include "shader_recompiler/frontend/maxwell/location.h"
#include "shader_recompiler/frontend/maxwell/opcodes.h"
#include "shader_recompiler/object_pool.h"

namespace Shader::IR {
class Block;
}

namespace Shader::Maxwell::Flow {

using FunctionId = size_t;

enum class EndClass {
    Branch,
    Exit,
    Return,
};

enum class Token {
    SSY,
    PBK,
    PEXIT,
    PRET,
    PCNT,
    PLONGJMP,
};

struct StackEntry {
    auto operator<=>(const StackEntry&) const noexcept = default;

    Token token;
    Location target;
};

class Stack {
public:
    void Push(Token token, Location target);
    [[nodiscard]] std::pair<Location, Stack> Pop(Token token) const;
    [[nodiscard]] std::optional<Location> Peek(Token token) const;
    [[nodiscard]] Stack Remove(Token token) const;

private:
    boost::container::small_vector<StackEntry, 3> entries;
};

struct Block : boost::intrusive::set_base_hook<
                   // Normal link is ~2.5% faster compared to safe link
                   boost::intrusive::link_mode<boost::intrusive::normal_link>> {
    [[nodiscard]] bool Contains(Location pc) const noexcept;

    bool operator<(const Block& rhs) const noexcept {
        return begin < rhs.begin;
    }

    Location begin;
    Location end;
    EndClass end_class;
    Stack stack;
    IR::Condition cond;
    Block* branch_true;
    Block* branch_false;
    IR::Block* ir;
};

struct Label {
    Location address;
    Block* block;
    Stack stack;
};

struct Function {
    Function(Location start_address);

    Location entrypoint;
    boost::container::small_vector<Label, 16> labels;
    boost::intrusive::set<Block> blocks;
};

class CFG {
    enum class AnalysisState {
        Branch,
        Continue,
    };

public:
    explicit CFG(Environment& env, ObjectPool<Block>& block_pool, Location start_address);

    CFG& operator=(const CFG&) = delete;
    CFG(const CFG&) = delete;

    CFG& operator=(CFG&&) = delete;
    CFG(CFG&&) = delete;

    [[nodiscard]] std::string Dot() const;

    [[nodiscard]] std::span<const Function> Functions() const noexcept {
        return std::span(functions.data(), functions.size());
    }
    [[nodiscard]] std::span<Function> Functions() noexcept {
        return std::span(functions.data(), functions.size());
    }

private:
    void AnalyzeLabel(FunctionId function_id, Label& label);

    /// Inspect already visited blocks.
    /// Return true when the block has already been visited
    bool InspectVisitedBlocks(FunctionId function_id, const Label& label);

    AnalysisState AnalyzeInst(Block* block, FunctionId function_id, Location pc);

    void AnalyzeCondInst(Block* block, FunctionId function_id, Location pc, EndClass insn_end_class,
                         IR::Condition cond);

    /// Return true when the branch instruction is confirmed to be a branch
    bool AnalyzeBranch(Block* block, FunctionId function_id, Location pc, Instruction inst,
                       Opcode opcode);

    void AnalyzeBRA(Block* block, FunctionId function_id, Location pc, Instruction inst,
                    bool is_absolute);
    void AnalyzeBRX(Block* block, Location pc, Instruction inst, bool is_absolute);
    void AnalyzeCAL(Location pc, Instruction inst, bool is_absolute);
    AnalysisState AnalyzeEXIT(Block* block, FunctionId function_id, Location pc, Instruction inst);

    /// Return the branch target block id
    Block* AddLabel(Block* block, Stack stack, Location pc, FunctionId function_id);

    Environment& env;
    ObjectPool<Block>& block_pool;
    boost::container::small_vector<Function, 1> functions;
    FunctionId current_function_id{0};
};

} // namespace Shader::Maxwell::Flow