summaryrefslogtreecommitdiffstats
path: root/src/video_core/shader/ast.cpp
blob: 56a1b29f323443b652945e0b1c57ecc5ea687d26 (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
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
// Copyright 2019 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.

#include <string>

#include "common/assert.h"
#include "common/common_types.h"
#include "video_core/shader/ast.h"
#include "video_core/shader/expr.h"

namespace VideoCommon::Shader {

ASTZipper::ASTZipper() = default;
ASTZipper::ASTZipper(ASTNode new_first) : first{}, last{} {
    first = new_first;
    last = new_first;
    ASTNode current = first;
    while (current) {
        current->manager = this;
        last = current;
        current = current->next;
    }
}

void ASTZipper::PushBack(ASTNode new_node) {
    new_node->previous = last;
    if (last) {
        last->next = new_node;
    }
    new_node->next.reset();
    last = new_node;
    if (!first) {
        first = new_node;
    }
    new_node->manager = this;
}

void ASTZipper::PushFront(ASTNode new_node) {
    new_node->previous.reset();
    new_node->next = first;
    if (first) {
        first->previous = first;
    }
    first = new_node;
    if (!last) {
        last = new_node;
    }
    new_node->manager = this;
}

void ASTZipper::InsertAfter(ASTNode new_node, ASTNode at_node) {
    if (!at_node) {
        PushFront(new_node);
        return;
    }
    new_node->previous = at_node;
    if (at_node == last) {
        last = new_node;
    }
    new_node->next = at_node->next;
    at_node->next = new_node;
    new_node->manager = this;
}

void ASTZipper::SetParent(ASTNode new_parent) {
    ASTNode current = first;
    while (current) {
        current->parent = new_parent;
        current = current->next;
    }
}

void ASTZipper::DetachTail(ASTNode node) {
    ASSERT(node->manager == this);
    if (node == first) {
        first.reset();
        last.reset();
        return;
    }

    last = node->previous;
    node->previous.reset();
}

void ASTZipper::DetachSegment(ASTNode start, ASTNode end) {
    ASSERT(start->manager == this && end->manager == this);
    ASTNode prev = start->previous;
    ASTNode post = end->next;
    if (!prev) {
        first = post;
    } else {
        prev->next = post;
    }
    if (!post) {
        last = prev;
    } else {
        post->previous = prev;
    }
    start->previous.reset();
    end->next.reset();
    ASTNode current = start;
    bool found = false;
    while (current) {
        current->manager = nullptr;
        current->parent.reset();
        found |= current == end;
        current = current->next;
    }
    ASSERT(found);
}

void ASTZipper::DetachSingle(ASTNode node) {
    ASSERT(node->manager == this);
    ASTNode prev = node->previous;
    ASTNode post = node->next;
    node->previous.reset();
    node->next.reset();
    if (!prev) {
        first = post;
    } else {
        prev->next = post;
    }
    if (!post) {
        last = prev;
    } else {
        post->previous = prev;
    }

    node->manager = nullptr;
    node->parent.reset();
}


void ASTZipper::Remove(ASTNode node) {
    ASSERT(node->manager == this);
    ASTNode next = node->next;
    ASTNode previous = node->previous;
    if (previous) {
        previous->next = next;
    }
    if (next) {
        next->previous = previous;
    }
    node->parent.reset();
    node->manager = nullptr;
    if (node == last) {
        last = previous;
    }
    if (node == first) {
        first = next;
    }
}

class ExprPrinter final {
public:
    ExprPrinter() = default;

    void operator()(ExprAnd const& expr) {
        inner += "( ";
        std::visit(*this, *expr.operand1);
        inner += " && ";
        std::visit(*this, *expr.operand2);
        inner += ')';
    }

    void operator()(ExprOr const& expr) {
        inner += "( ";
        std::visit(*this, *expr.operand1);
        inner += " || ";
        std::visit(*this, *expr.operand2);
        inner += ')';
    }

    void operator()(ExprNot const& expr) {
        inner += "!";
        std::visit(*this, *expr.operand1);
    }

    void operator()(ExprPredicate const& expr) {
        u32 pred = static_cast<u32>(expr.predicate);
        if (pred > 7) {
            inner += "!";
            pred -= 8;
        }
        inner += "P" + std::to_string(pred);
    }

    void operator()(ExprCondCode const& expr) {
        u32 cc = static_cast<u32>(expr.cc);
        inner += "CC" + std::to_string(cc);
    }

    void operator()(ExprVar const& expr) {
        inner += "V" + std::to_string(expr.var_index);
    }

    void operator()(ExprBoolean const& expr) {
        inner += expr.value ? "true" : "false";
    }

    std::string& GetResult() {
        return inner;
    }

    std::string inner{};
};

class ASTPrinter {
public:
    ASTPrinter() = default;

    void operator()(ASTProgram& ast) {
        scope++;
        inner += "program {\n";
        ASTNode current = ast.nodes.GetFirst();
        while (current) {
            Visit(current);
            current = current->GetNext();
        }
        inner += "}\n";
        scope--;
    }

    void operator()(ASTIfThen& ast) {
        ExprPrinter expr_parser{};
        std::visit(expr_parser, *ast.condition);
        inner += Ident() + "if (" + expr_parser.GetResult() + ") {\n";
        scope++;
        ASTNode current = ast.nodes.GetFirst();
        while (current) {
            Visit(current);
            current = current->GetNext();
        }
        scope--;
        inner += Ident() + "}\n";
    }

    void operator()(ASTIfElse& ast) {
        inner += Ident() + "else {\n";
        scope++;
        ASTNode current = ast.nodes.GetFirst();
        while (current) {
            Visit(current);
            current = current->GetNext();
        }
        scope--;
        inner += Ident() + "}\n";
    }

    void operator()(ASTBlockEncoded& ast) {
        inner += Ident() + "Block(" + std::to_string(ast.start) + ", " + std::to_string(ast.end) +
                 ");\n";
    }

    void operator()(ASTVarSet& ast) {
        ExprPrinter expr_parser{};
        std::visit(expr_parser, *ast.condition);
        inner +=
            Ident() + "V" + std::to_string(ast.index) + " := " + expr_parser.GetResult() + ";\n";
    }

    void operator()(ASTLabel& ast) {
        inner += "Label_" + std::to_string(ast.index) + ":\n";
    }

    void operator()(ASTGoto& ast) {
        ExprPrinter expr_parser{};
        std::visit(expr_parser, *ast.condition);
        inner += Ident() + "(" + expr_parser.GetResult() + ") -> goto Label_" +
                 std::to_string(ast.label) + ";\n";
    }

    void operator()(ASTDoWhile& ast) {
        ExprPrinter expr_parser{};
        std::visit(expr_parser, *ast.condition);
        inner += Ident() + "do {\n";
        scope++;
        ASTNode current = ast.nodes.GetFirst();
        while (current) {
            Visit(current);
            current = current->GetNext();
        }
        scope--;
        inner += Ident() + "} while (" + expr_parser.GetResult() + ")\n";
    }

    void operator()(ASTReturn& ast) {
        ExprPrinter expr_parser{};
        std::visit(expr_parser, *ast.condition);
        inner += Ident() + "(" + expr_parser.GetResult() + ") -> " +
                 (ast.kills ? "discard" : "exit") + ";\n";
    }

    void operator()(ASTBreak& ast) {
        ExprPrinter expr_parser{};
        std::visit(expr_parser, *ast.condition);
        inner += Ident() + "(" + expr_parser.GetResult() + ") -> break;\n";
    }

    std::string& Ident() {
        if (memo_scope == scope) {
            return tabs_memo;
        }
        tabs_memo = tabs.substr(0, scope * 2);
        memo_scope = scope;
        return tabs_memo;
    }

    void Visit(ASTNode& node) {
        std::visit(*this, *node->GetInnerData());
    }

    std::string& GetResult() {
        return inner;
    }

private:
    std::string inner{};
    u32 scope{};

    std::string tabs_memo{};
    u32 memo_scope{};

    static std::string tabs;
};

std::string ASTPrinter::tabs = "                                    ";

std::string ASTManager::Print() {
    ASTPrinter printer{};
    printer.Visit(main_node);
    return printer.GetResult();
}

#pragma optimize("", off)

void ASTManager::Decompile() {
    auto it = gotos.begin();
    while (it != gotos.end()) {
        ASTNode goto_node = *it;
        u32 label_index = goto_node->GetGotoLabel();
        ASTNode label = labels[label_index];
        if (IndirectlyRelated(goto_node, label)) {
            while (!DirectlyRelated(goto_node, label)) {
                MoveOutward(goto_node);
            }
        }
        if (DirectlyRelated(goto_node, label)) {
            u32 goto_level = goto_node->GetLevel();
            u32 label_level = goto_node->GetLevel();
            while (label_level > goto_level) {
                MoveOutward(goto_node);
                goto_level++;
            }
        }
        if (label->GetParent() == goto_node->GetParent()) {
            bool is_loop = false;
            ASTNode current = goto_node->GetPrevious();
            while (current) {
                if (current == label) {
                    is_loop = true;
                    break;
                }
                current = current->GetPrevious();
            }

            if (is_loop) {
                EncloseDoWhile(goto_node, label);
            } else {
                EncloseIfThen(goto_node, label);
            }
            it = gotos.erase(it);
            continue;
        }
        it++;
    }
    /*
    for (ASTNode label : labels) {
        auto& manager = label->GetManager();
        manager.Remove(label);
    }
    labels.clear();
    */
}

bool ASTManager::IndirectlyRelated(ASTNode first, ASTNode second) {
    return !(first->GetParent() == second->GetParent() || DirectlyRelated(first, second));
}

bool ASTManager::DirectlyRelated(ASTNode first, ASTNode second) {
    if (first->GetParent() == second->GetParent()) {
        return false;
    }
    u32 first_level = first->GetLevel();
    u32 second_level = second->GetLevel();
    u32 min_level;
    u32 max_level;
    ASTNode max;
    ASTNode min;
    if (first_level > second_level) {
        min_level = second_level;
        min = second;
        max_level = first_level;
        max = first;
    } else {
        min_level = first_level;
        min = first;
        max_level = second_level;
        max = second;
    }

    while (min_level < max_level) {
        min_level++;
        min = min->GetParent();
    }

    return (min->GetParent() == max->GetParent());
}

void ASTManager::EncloseDoWhile(ASTNode goto_node, ASTNode label) {
    ASTZipper& zipper = goto_node->GetManager();
    ASTNode loop_start = label->GetNext();
    if (loop_start == goto_node) {
        zipper.Remove(goto_node);
        return;
    }
    ASTNode parent = label->GetParent();
    Expr condition = goto_node->GetGotoCondition();
    zipper.DetachSegment(loop_start, goto_node);
    ASTNode do_while_node = ASTBase::Make<ASTDoWhile>(parent, condition, ASTZipper(loop_start));
    zipper.InsertAfter(do_while_node, label);
    ASTZipper* sub_zipper = do_while_node->GetSubNodes();
    sub_zipper->SetParent(do_while_node);
    sub_zipper->Remove(goto_node);
}

void ASTManager::EncloseIfThen(ASTNode goto_node, ASTNode label) {
    ASTZipper& zipper = goto_node->GetManager();
    ASTNode if_end = label->GetPrevious();
    if (if_end == goto_node) {
        zipper.Remove(goto_node);
        return;
    }
    ASTNode prev = goto_node->GetPrevious();
    ASTNode parent = label->GetParent();
    Expr condition = goto_node->GetGotoCondition();
    Expr neg_condition = MakeExpr<ExprNot>(condition);
    zipper.DetachSegment(goto_node, if_end);
    ASTNode if_node = ASTBase::Make<ASTIfThen>(parent, condition, ASTZipper(goto_node));
    zipper.InsertAfter(if_node, prev);
    ASTZipper* sub_zipper = if_node->GetSubNodes();
    sub_zipper->SetParent(if_node);
    sub_zipper->Remove(goto_node);
}

void ASTManager::MoveOutward(ASTNode goto_node) {
    ASTZipper& zipper = goto_node->GetManager();
    ASTNode parent = goto_node->GetParent();
    bool is_loop = parent->IsLoop();
    bool is_if = parent->IsIfThen() || parent->IsIfElse();

    ASTNode prev = goto_node->GetPrevious();

    Expr condition = goto_node->GetGotoCondition();
    u32 var_index = NewVariable();
    Expr var_condition = MakeExpr<ExprVar>(var_index);
    ASTNode var_node = ASTBase::Make<ASTVarSet>(parent, var_index, condition);
    zipper.DetachSingle(goto_node);
    zipper.InsertAfter(var_node, prev);
    goto_node->SetGotoCondition(var_condition);
    if (is_loop) {
        ASTNode break_node = ASTBase::Make<ASTBreak>(parent, var_condition);
        zipper.InsertAfter(break_node, var_node);
    } else if (is_if) {
        ASTNode post = var_node->GetNext();
        if (post) {
            zipper.DetachTail(post);
            ASTNode if_node = ASTBase::Make<ASTIfThen>(parent, var_condition, ASTZipper(post));
            zipper.InsertAfter(if_node, var_node);
            ASTZipper* sub_zipper = if_node->GetSubNodes();
            sub_zipper->SetParent(if_node);
        }
    } else {
        UNREACHABLE();
    }
    ASTZipper& zipper2 = parent->GetManager();
    ASTNode next = parent->GetNext();
    if (is_if && next && next->IsIfElse()) {
        zipper2.InsertAfter(goto_node, next);
        return;
    }
    zipper2.InsertAfter(goto_node, parent);
}

} // namespace VideoCommon::Shader