1 | #include "taichi/ir/analysis.h" |
2 | #include "taichi/ir/ir.h" |
3 | #include "taichi/ir/statements.h" |
4 | #include "taichi/ir/transforms.h" |
5 | #include "taichi/ir/visitors.h" |
6 | #include "taichi/transforms/utils.h" |
7 | |
8 | #include <typeinfo> |
9 | #include <algorithm> |
10 | |
11 | namespace taichi::lang { |
12 | |
13 | class IndependentBlockMetaData { |
14 | public: |
15 | bool is_ib = true; |
16 | bool is_smallest_ib = true; |
17 | }; |
18 | |
19 | class NonLinearOps { |
20 | public: |
21 | inline static const std::set<TernaryOpType> ternary_collections{ |
22 | TernaryOpType::select}; |
23 | inline static const std::set<UnaryOpType> unary_collections{ |
24 | UnaryOpType::abs, UnaryOpType::sin, UnaryOpType::cos, |
25 | UnaryOpType::tanh, UnaryOpType::asin, UnaryOpType::acos, |
26 | UnaryOpType::exp, UnaryOpType::log, UnaryOpType::sqrt}; |
27 | inline static const std::set<BinaryOpType> binary_collections{ |
28 | BinaryOpType::mul, BinaryOpType::div, BinaryOpType::atan2, |
29 | BinaryOpType::pow}; |
30 | }; |
31 | |
32 | class IndependentBlocksJudger : public BasicStmtVisitor { |
33 | public: |
34 | using BasicStmtVisitor::visit; |
35 | |
36 | void visit(LocalLoadStmt *stmt) override { |
37 | TI_ASSERT(stmt->src->is<AllocaStmt>() || stmt->src->is<MatrixPtrStmt>()); |
38 | touched_allocas_.insert(stmt->src); |
39 | } |
40 | |
41 | void visit(LocalStoreStmt *stmt) override { |
42 | TI_ASSERT(stmt->dest->is<AllocaStmt>() || stmt->dest->is<MatrixPtrStmt>()); |
43 | touched_allocas_.insert(stmt->dest); |
44 | } |
45 | |
46 | void visit(AtomicOpStmt *stmt) override { |
47 | // We don't need to check the global atomics inside the range for-loops |
48 | // because |
49 | // 1. If the range for-loop is innermost, they will be captured by |
50 | // MakeAdjoint anyway |
51 | // 2. If the range for-loop is not innermost, they will be processed by |
52 | // another IndependentBlocksJudger |
53 | if (is_inside_loop_) |
54 | return; |
55 | TI_ASSERT(stmt->dest->is<GlobalPtrStmt>()); |
56 | if (stmt->dest->as<GlobalPtrStmt>()->snode->has_adjoint()) { |
57 | qualified_glb_operations_ = true; |
58 | } |
59 | } |
60 | |
61 | void visit(GlobalLoadStmt *stmt) override { |
62 | // We don't need to check the global load inside the range for-loops |
63 | // because |
64 | // 1. If the range for-loop is innermost, they will be captured by |
65 | // MakeAdjoint anyway |
66 | // 2. If the range for-loop is not innermost, they will be processed by |
67 | // another IndependentBlocksJudger |
68 | if (is_inside_loop_) |
69 | return; |
70 | // TODO: handle external ptr stmt after autodiff supporting ndarray |
71 | if (stmt->src->is<GlobalPtrStmt>() && |
72 | stmt->src->as<GlobalPtrStmt>()->snode->has_adjoint()) { |
73 | qualified_glb_operations_ = true; |
74 | } |
75 | } |
76 | |
77 | void visit(RangeForStmt *stmt) override { |
78 | inner_most_loop_ = false; |
79 | is_inside_loop_ = true; |
80 | stmt->body->accept(this); |
81 | is_inside_loop_ = false; |
82 | } |
83 | |
84 | static void run(IRNode *root, IndependentBlockMetaData &ib_meta_data) { |
85 | IndependentBlocksJudger Judger; |
86 | Block *block = root->as<Block>(); |
87 | root->accept(&Judger); |
88 | std::set<Block *> outside_blocks; |
89 | // Collect all parent blocks (i.e. outside blocks) of the current block for |
90 | // local load/store stmt checks |
91 | for (auto b = block->parent_block(); b; b = b->parent_block()) { |
92 | if (b) |
93 | outside_blocks.insert(b); |
94 | } |
95 | for (const auto &alloca : Judger.touched_allocas_) { |
96 | // Test if the alloca belongs to the current block |
97 | if (outside_blocks.find(alloca->parent) != outside_blocks.end()) { |
98 | // This block is not an IB since it loads/modifies outside variables |
99 | ib_meta_data.is_ib = false; |
100 | } |
101 | } |
102 | |
103 | // To judge whether a block is an IB |
104 | // - No local load/store to allocas *outside* itself has been strictly |
105 | // enforced |
106 | |
107 | // To judge whether a block is a smallest IB |
108 | // - If the #1 is satisfied, either an inner most loop or a block without |
109 | // global atomics / global load is an IB |
110 | ib_meta_data.is_smallest_ib = |
111 | ib_meta_data.is_ib && |
112 | (Judger.qualified_glb_operations_ || Judger.inner_most_loop_); |
113 | } |
114 | |
115 | private: |
116 | std::set<Stmt *> touched_allocas_; |
117 | bool qualified_glb_operations_ = false; |
118 | bool inner_most_loop_ = true; |
119 | bool is_inside_loop_ = false; |
120 | }; |
121 | |
122 | // Remove the duplicated IBs, remove blocks who are others' children because |
123 | // each block should only be processed once |
124 | class DuplicateIndependentBlocksCleaner : public BasicStmtVisitor { |
125 | public: |
126 | using BasicStmtVisitor::visit; |
127 | |
128 | void check_children_ib(Block *target_block) { |
129 | // Remove the block if it is the child of the block being visiting |
130 | if (independent_blocks_cleaned_.find(target_block) != |
131 | independent_blocks_cleaned_.end()) { |
132 | independent_blocks_cleaned_.erase(target_block); |
133 | } |
134 | } |
135 | |
136 | void visit(StructForStmt *stmt) override { |
137 | check_children_ib(stmt->body.get()); |
138 | stmt->body->accept(this); |
139 | } |
140 | void visit(RangeForStmt *stmt) override { |
141 | check_children_ib(stmt->body.get()); |
142 | stmt->body->accept(this); |
143 | } |
144 | |
145 | static std::set<Block *> run( |
146 | const std::vector<std::pair<int, Block *>> &raw_IBs) { |
147 | DuplicateIndependentBlocksCleaner cleaner; |
148 | // Remove duplicate IBs |
149 | for (auto const &item : raw_IBs) { |
150 | cleaner.independent_blocks_cleaned_.insert(item.second); |
151 | } |
152 | // No clean is needed if only one IB exists |
153 | if (cleaner.independent_blocks_cleaned_.size() > 1) { |
154 | // Check from the block with smallest depth, ensure no duplicate visit |
155 | // happens |
156 | for (const auto &block : cleaner.independent_blocks_cleaned_) { |
157 | block->accept(&cleaner); |
158 | } |
159 | } |
160 | return cleaner.independent_blocks_cleaned_; |
161 | } |
162 | |
163 | private: |
164 | std::set<Block *> independent_blocks_cleaned_; |
165 | }; |
166 | |
167 | // Do automatic differentiation pass in the reverse order (reverse-mode AD) |
168 | |
169 | // Independent Block (IB): blocks (i.e. loop bodies) whose iterations are |
170 | // independent of previous iterations and outer scopes. IBs are where the |
171 | // MakeAdjoint pass happens. IBs may contain if's and for-loops. |
172 | |
173 | // IBs are not always the inner-most for loop body. If the inner-most for-loop |
174 | // has iterations that carry iteration-dependent variables, it's not an IB. |
175 | |
176 | // Clearly the outermost level is always an IB, but we want IBs to be as small |
177 | // as possible. Outside IBs, we just need to reverse the for-loop orders. |
178 | |
179 | // Figure out the IBs. |
180 | class IdentifyIndependentBlocks : public BasicStmtVisitor { |
181 | public: |
182 | using BasicStmtVisitor::visit; |
183 | |
184 | void visit(WhileStmt *stmt) override { |
185 | TI_ERROR("WhileStmt is not supported in AutoDiff." ); |
186 | } |
187 | |
188 | void visit(ContinueStmt *stmt) override { |
189 | TI_ERROR("ContinueStmt is not supported in AutoDiff." ); |
190 | } |
191 | |
192 | void visit(WhileControlStmt *stmt) override { |
193 | TI_ERROR("WhileControlStmt (break) is not supported in AutoDiff." ); |
194 | } |
195 | |
196 | void visit_loop_body(Block *block) { |
197 | auto ib_meta_data = IndependentBlockMetaData(); |
198 | // An IB has no local load/store to allocas *outside* itself |
199 | // Note: |
200 | // - Local atomics should have been demoted before this pass. |
201 | // - It is OK for an IB to have more than two for loops. |
202 | // - No global load/atomics operations to the global variables which |
203 | // require gradient |
204 | if (block->statements.empty()) { |
205 | // A empty block shoud be a smallest IB |
206 | ib_meta_data.is_ib = true; |
207 | ib_meta_data.is_smallest_ib = true; |
208 | } else { |
209 | IndependentBlocksJudger::run(block, ib_meta_data); |
210 | } |
211 | |
212 | if (ib_meta_data.is_smallest_ib) { |
213 | independent_blocks_.push_back({depth_, block}); |
214 | } else if (ib_meta_data.is_ib) { |
215 | current_ib_ = block; |
216 | block->accept(this); |
217 | } else { |
218 | if (depth_ <= 1) { |
219 | TI_ASSERT(depth_ == 1); |
220 | // The top level block is already not an IB, store it |
221 | independent_blocks_.push_back({depth_ - 1, block}); |
222 | } else { |
223 | independent_blocks_.push_back({depth_ - 1, block->parent_block()}); |
224 | } |
225 | } |
226 | } |
227 | |
228 | void visit(StructForStmt *stmt) override { |
229 | TI_ASSERT(depth_ == 0); |
230 | depth_++; |
231 | current_ib_ = stmt->body.get(); |
232 | visit_loop_body(stmt->body.get()); |
233 | depth_--; |
234 | } |
235 | |
236 | void visit(RangeForStmt *stmt) override { |
237 | if (depth_ == 0) { |
238 | current_ib_ = stmt->body.get(); |
239 | } |
240 | depth_++; |
241 | visit_loop_body(stmt->body.get()); |
242 | depth_--; |
243 | } |
244 | |
245 | static std::set<Block *> run(IRNode *root) { |
246 | IdentifyIndependentBlocks pass; |
247 | Block *block = root->as<Block>(); |
248 | bool has_for = false; |
249 | for (auto &s : block->statements) { |
250 | if (s->is<StructForStmt>() || s->is<RangeForStmt>()) { |
251 | has_for = true; |
252 | } |
253 | } |
254 | if (!has_for) { |
255 | // The whole block is an IB |
256 | pass.independent_blocks_.push_back({0, block}); |
257 | } else { |
258 | root->accept(&pass); |
259 | } |
260 | // Sort the IBs by their depth from shallow to deep |
261 | std::sort(pass.independent_blocks_.begin(), pass.independent_blocks_.end(), |
262 | [](const std::pair<int, Block *> &a, |
263 | const std::pair<int, Block *> &b) -> bool { |
264 | return a.first < b.first; |
265 | }); |
266 | |
267 | TI_ASSERT(!pass.independent_blocks_.empty()); |
268 | return DuplicateIndependentBlocksCleaner::run(pass.independent_blocks_); |
269 | } |
270 | |
271 | private: |
272 | std::vector<std::pair<int, Block *>> independent_blocks_; |
273 | int depth_{0}; |
274 | Block *current_ib_{nullptr}; |
275 | }; |
276 | |
277 | // Note that SSA does not mean the instruction will be executed at most once. |
278 | // For instructions that may be executed multiple times, we treat them as a |
279 | // mutable local variables. |
280 | class PromoteSSA2LocalVar : public BasicStmtVisitor { |
281 | using BasicStmtVisitor::visit; |
282 | |
283 | explicit PromoteSSA2LocalVar(Block *block) { |
284 | alloca_block_ = block; |
285 | invoke_default_visitor = true; |
286 | execute_once_ = true; |
287 | } |
288 | |
289 | void visit(Stmt *stmt) override { |
290 | if (execute_once_) |
291 | return; |
292 | if (!(stmt->is<UnaryOpStmt>() || stmt->is<BinaryOpStmt>() || |
293 | stmt->is<TernaryOpStmt>() || stmt->is<GlobalLoadStmt>() || |
294 | stmt->is<AllocaStmt>())) { |
295 | // TODO: this list may be incomplete |
296 | return; |
297 | } |
298 | |
299 | if (stmt->is<AllocaStmt>()) { |
300 | // Create a new alloc at the top of an ib to replace the old alloca |
301 | auto alloc = Stmt::make<AllocaStmt>(stmt->ret_type); |
302 | auto alloc_ptr = alloc.get(); |
303 | TI_ASSERT(alloca_block_); |
304 | alloca_block_->insert(std::move(alloc), 0); |
305 | // Replace all the usages of the old stmt with that of the new one |
306 | irpass::replace_all_usages_with(stmt->parent, stmt, alloc_ptr); |
307 | |
308 | // Replace the old alloca with a local store |
309 | // and it will be replaced by a AdStackPushStmt in the following |
310 | // ReplaceLocalVarWithStacks pass |
311 | auto dtype = stmt->ret_type; |
312 | auto zero = |
313 | stmt->insert_after_me(Stmt::make<ConstStmt>(TypedConstant(dtype, 0))); |
314 | zero->insert_after_me(Stmt::make<LocalStoreStmt>(alloc_ptr, zero)); |
315 | // Remove the old stmt |
316 | stmt->parent->erase(stmt); |
317 | } else { |
318 | // Create a alloc |
319 | auto alloc = Stmt::make<AllocaStmt>(stmt->ret_type); |
320 | auto alloc_ptr = alloc.get(); |
321 | TI_ASSERT(alloca_block_); |
322 | alloca_block_->insert(std::move(alloc), 0); |
323 | auto load = stmt->insert_after_me(Stmt::make<LocalLoadStmt>(alloc_ptr)); |
324 | irpass::replace_all_usages_with(stmt->parent, stmt, load); |
325 | // Create the load first so that the operand of the store won't get |
326 | // replaced |
327 | stmt->insert_after_me(Stmt::make<LocalStoreStmt>(alloc_ptr, stmt)); |
328 | } |
329 | } |
330 | |
331 | void visit(RangeForStmt *stmt) override { |
332 | auto old_execute_once = execute_once_; |
333 | execute_once_ = false; // loop body may be executed many times |
334 | stmt->body->accept(this); |
335 | execute_once_ = old_execute_once; |
336 | } |
337 | |
338 | private: |
339 | Block *alloca_block_{nullptr}; |
340 | bool execute_once_; |
341 | |
342 | public: |
343 | static void run(Block *block) { |
344 | PromoteSSA2LocalVar pass(block); |
345 | block->accept(&pass); |
346 | } |
347 | }; |
348 | |
349 | class AdStackAllocaJudger : public BasicStmtVisitor { |
350 | public: |
351 | using BasicStmtVisitor::visit; |
352 | // Find the usage of the stmt recursively along the LocalLoadStmt |
353 | void visit(LocalLoadStmt *stmt) override { |
354 | if (stmt->src == target_alloca_) { |
355 | local_loaded_ = true; |
356 | target_alloca_ = stmt; |
357 | } |
358 | } |
359 | |
360 | // Check if there is a LocalLoadStmt - LocalStoreStmt cycle for an alloca |
361 | // Check if the alloca is load only |
362 | void visit(LocalStoreStmt *stmt) override { |
363 | if (stmt->dest == target_alloca_backup_) |
364 | load_only_ = false; |
365 | if (local_loaded_ && stmt->dest == target_alloca_backup_) { |
366 | is_stack_needed_ = true; |
367 | } |
368 | } |
369 | |
370 | // Check if the alloca is load only |
371 | void visit(AtomicOpStmt *stmt) override { |
372 | if (stmt->dest == target_alloca_backup_) |
373 | load_only_ = false; |
374 | } |
375 | |
376 | // The stack is needed if the alloc serves as the index of any global |
377 | // variables |
378 | void visit(GlobalPtrStmt *stmt) override { |
379 | if (is_stack_needed_) |
380 | return; |
381 | for (const auto &index : stmt->indices) { |
382 | if (index == target_alloca_) |
383 | is_stack_needed_ = true; |
384 | } |
385 | } |
386 | |
387 | // Check whether the target stmt is used by the UnaryOpStmts who requires the |
388 | // ad stack |
389 | void visit(UnaryOpStmt *stmt) override { |
390 | if (is_stack_needed_) |
391 | return; |
392 | if (NonLinearOps::unary_collections.find(stmt->op_type) != |
393 | NonLinearOps::unary_collections.end()) { |
394 | if (stmt->operand == target_alloca_) |
395 | is_stack_needed_ = true; |
396 | } |
397 | } |
398 | |
399 | // Check whether the target stmt is used by the BinaryOpStmts who requires the |
400 | // ad stack |
401 | void visit(BinaryOpStmt *stmt) override { |
402 | if (is_stack_needed_) |
403 | return; |
404 | if (NonLinearOps::binary_collections.find(stmt->op_type) != |
405 | NonLinearOps::binary_collections.end()) { |
406 | if (stmt->lhs == target_alloca_ || stmt->rhs == target_alloca_) |
407 | is_stack_needed_ = true; |
408 | } |
409 | } |
410 | |
411 | // Check whether the target stmt is used by the TernaryOpStmts who requires |
412 | // the ad stack |
413 | void visit(TernaryOpStmt *stmt) override { |
414 | if (is_stack_needed_) |
415 | return; |
416 | if (NonLinearOps::ternary_collections.find(stmt->op_type) != |
417 | NonLinearOps::ternary_collections.end()) { |
418 | if (stmt->op1 == target_alloca_ || stmt->op2 == target_alloca_ || |
419 | stmt->op3 == target_alloca_) |
420 | is_stack_needed_ = true; |
421 | } |
422 | } |
423 | |
424 | // Check whether the target serves as the condition of a if stmt |
425 | void visit(IfStmt *stmt) override { |
426 | if (is_stack_needed_) |
427 | return; |
428 | |
429 | if (stmt->cond == target_alloca_) { |
430 | is_stack_needed_ = true; |
431 | return; |
432 | } |
433 | |
434 | if (stmt->true_statements) |
435 | stmt->true_statements->accept(this); |
436 | if (stmt->false_statements) |
437 | stmt->false_statements->accept(this); |
438 | } |
439 | |
440 | static bool run(AllocaStmt *target_alloca) { |
441 | AdStackAllocaJudger judger; |
442 | judger.target_alloca_ = target_alloca; |
443 | judger.target_alloca_backup_ = target_alloca; |
444 | target_alloca->parent->accept(&judger); |
445 | return (!judger.load_only_) && judger.is_stack_needed_; |
446 | } |
447 | |
448 | private: |
449 | Stmt *target_alloca_; |
450 | Stmt *target_alloca_backup_; |
451 | bool is_stack_needed_ = false; |
452 | bool local_loaded_ = false; |
453 | bool load_only_ = true; |
454 | }; |
455 | |
456 | class ReplaceLocalVarWithStacks : public BasicStmtVisitor { |
457 | public: |
458 | using BasicStmtVisitor::visit; |
459 | int ad_stack_size; |
460 | explicit ReplaceLocalVarWithStacks(int ad_stack_size) |
461 | : ad_stack_size(ad_stack_size) { |
462 | } |
463 | |
464 | void visit(AllocaStmt *alloc) override { |
465 | bool is_stack_needed = AdStackAllocaJudger::run(alloc); |
466 | if (is_stack_needed) { |
467 | auto dtype = alloc->ret_type; |
468 | auto stack_alloca = Stmt::make<AdStackAllocaStmt>(dtype, ad_stack_size); |
469 | auto stack_alloca_ptr = stack_alloca.get(); |
470 | |
471 | alloc->replace_with(VecStatement(std::move(stack_alloca))); |
472 | |
473 | // Note that unlike AllocaStmt, AdStackAllocaStmt does NOT have an 0 as |
474 | // initial value. Therefore here we push an initial 0 value. |
475 | auto zero = stack_alloca_ptr->insert_after_me( |
476 | Stmt::make<ConstStmt>(TypedConstant(dtype, 0))); |
477 | zero->insert_after_me( |
478 | Stmt::make<AdStackPushStmt>(stack_alloca_ptr, zero)); |
479 | } |
480 | } |
481 | |
482 | void visit(LocalLoadStmt *stmt) override { |
483 | if (stmt->src->is<AdStackAllocaStmt>()) |
484 | stmt->replace_with(Stmt::make<AdStackLoadTopStmt>(stmt->src)); |
485 | } |
486 | |
487 | void visit(LocalStoreStmt *stmt) override { |
488 | if (stmt->dest->is<AdStackAllocaStmt>()) |
489 | stmt->replace_with(Stmt::make<AdStackPushStmt>(stmt->dest, stmt->val)); |
490 | } |
491 | }; |
492 | |
493 | class ReverseOuterLoops : public BasicStmtVisitor { |
494 | using BasicStmtVisitor::visit; |
495 | |
496 | private: |
497 | explicit ReverseOuterLoops(const std::set<Block *> &IB) |
498 | : loop_depth_(0), ib_(IB) { |
499 | } |
500 | |
501 | bool is_ib(Block *block) const { |
502 | return std::find(ib_.begin(), ib_.end(), block) != ib_.end(); |
503 | } |
504 | |
505 | void visit(StructForStmt *stmt) override { |
506 | loop_depth_ += 1; |
507 | if (!is_ib(stmt->body.get())) |
508 | stmt->body->accept(this); |
509 | loop_depth_ -= 1; |
510 | } |
511 | |
512 | void visit(RangeForStmt *stmt) override { |
513 | if (loop_depth_ >= 1) { |
514 | stmt->reversed = !stmt->reversed; |
515 | } |
516 | loop_depth_ += 1; |
517 | if (!is_ib(stmt->body.get())) |
518 | stmt->body->accept(this); |
519 | loop_depth_ -= 1; |
520 | } |
521 | |
522 | int loop_depth_; |
523 | std::set<Block *> ib_; |
524 | |
525 | public: |
526 | static void run(IRNode *root, const std::set<Block *> &IB) { |
527 | ReverseOuterLoops pass(IB); |
528 | root->accept(&pass); |
529 | } |
530 | }; |
531 | |
532 | // Base class for both reverse (make adjoint) and forward (make dual) mode |
533 | class ADTransform : public IRVisitor { |
534 | protected: |
535 | Stmt *constant(float32 x) { |
536 | return insert<ConstStmt>(TypedConstant(x)); |
537 | } |
538 | |
539 | // utils |
540 | Stmt *sgn(Stmt *inp) { |
541 | return insert<UnaryOpStmt>(UnaryOpType::sgn, load(inp)); |
542 | } |
543 | |
544 | // utils |
545 | Stmt *negate(Stmt *inp) { |
546 | return insert<UnaryOpStmt>(UnaryOpType::neg, load(inp)); |
547 | } |
548 | |
549 | Stmt *sqrt(Stmt *inp) { |
550 | return insert<UnaryOpStmt>(UnaryOpType::sqrt, load(inp)); |
551 | } |
552 | |
553 | Stmt *rsqrt(Stmt *inp) { |
554 | return insert<UnaryOpStmt>(UnaryOpType::rsqrt, load(inp)); |
555 | } |
556 | |
557 | Stmt *mul(Stmt *op1, Stmt *op2) { |
558 | return insert<BinaryOpStmt>(BinaryOpType::mul, load(op1), load(op2)); |
559 | } |
560 | |
561 | Stmt *sqr(Stmt *op1) { |
562 | return mul(op1, op1); |
563 | } |
564 | |
565 | Stmt *add(Stmt *op1, Stmt *op2) { |
566 | return insert<BinaryOpStmt>(BinaryOpType::add, load(op1), load(op2)); |
567 | } |
568 | |
569 | Stmt *cmp_lt(Stmt *op1, Stmt *op2) { |
570 | return insert<BinaryOpStmt>(BinaryOpType::cmp_lt, load(op1), load(op2)); |
571 | } |
572 | |
573 | Stmt *sub(Stmt *op1, Stmt *op2) { |
574 | return insert<BinaryOpStmt>(BinaryOpType::sub, load(op1), load(op2)); |
575 | } |
576 | |
577 | Stmt *div(Stmt *op1, Stmt *op2) { |
578 | return insert<BinaryOpStmt>(BinaryOpType::div, load(op1), load(op2)); |
579 | } |
580 | |
581 | Stmt *sel(Stmt *op1, Stmt *op2, Stmt *op3) { |
582 | return insert<TernaryOpStmt>(TernaryOpType::select, load(op1), load(op2), |
583 | load(op3)); |
584 | } |
585 | |
586 | Stmt *cos(Stmt *op1) { |
587 | return insert<UnaryOpStmt>(UnaryOpType::cos, load(op1)); |
588 | } |
589 | |
590 | Stmt *sin(Stmt *op1) { |
591 | return insert<UnaryOpStmt>(UnaryOpType::sin, load(op1)); |
592 | } |
593 | |
594 | Stmt *log(Stmt *op1) { |
595 | return insert<UnaryOpStmt>(UnaryOpType::log, load(op1)); |
596 | } |
597 | |
598 | Stmt *pow(Stmt *op1, Stmt *op2) { |
599 | return insert<BinaryOpStmt>(BinaryOpType::pow, load(op1), load(op2)); |
600 | } |
601 | |
602 | public: |
603 | virtual Stmt *insert_grad_stmt(std::unique_ptr<Stmt> &&stmt) = 0; |
604 | |
605 | template <typename T, typename... Args> |
606 | Stmt *insert(Args &&...args) { |
607 | return insert_grad_stmt(Stmt::make<T>(args...)); |
608 | } |
609 | |
610 | void visit(AllocaStmt *alloca) override { |
611 | // do nothing. |
612 | } |
613 | |
614 | void visit(AdStackAllocaStmt *alloca) override { |
615 | // do nothing. |
616 | } |
617 | |
618 | void visit(ArgLoadStmt *stmt) override { |
619 | // do nothing. |
620 | } |
621 | |
622 | void visit(LoopIndexStmt *stmt) override { |
623 | // do nothing. |
624 | } |
625 | |
626 | void visit(MatrixPtrStmt *stmt) override { |
627 | // do nothing. |
628 | } |
629 | |
630 | void visit(PrintStmt *print_stmt) override { |
631 | // do nothing |
632 | } |
633 | |
634 | void visit(ConstStmt *const_stmt) override { |
635 | // do nothing |
636 | } |
637 | |
638 | void visit(WhileControlStmt *stmt) override { |
639 | TI_NOT_IMPLEMENTED |
640 | } |
641 | |
642 | void visit(ContinueStmt *stmt) override { |
643 | TI_NOT_IMPLEMENTED; |
644 | } |
645 | |
646 | void visit(WhileStmt *stmt) override { |
647 | TI_NOT_IMPLEMENTED |
648 | } |
649 | |
650 | void visit(GlobalPtrStmt *stmt) override { |
651 | // do nothing |
652 | } |
653 | |
654 | Stmt *load(Stmt *alloc) { |
655 | TI_ASSERT(alloc != nullptr); |
656 | if (alloc->is<AllocaStmt>()) { |
657 | return insert<LocalLoadStmt>(alloc); |
658 | } else { |
659 | // non alloca |
660 | return alloc; |
661 | } |
662 | } |
663 | |
664 | bool gradients_stopped(GlobalLoadStmt *stmt, SNode *snode) { |
665 | for (auto block = stmt->parent; block; block = block->parent_block()) { |
666 | for (auto s : block->stop_gradients) { |
667 | if (s == snode) { |
668 | return true; |
669 | } |
670 | } |
671 | } |
672 | return false; |
673 | } |
674 | |
675 | void visit(AssertStmt *stmt) override { |
676 | // do nothing |
677 | } |
678 | |
679 | void visit(RangeAssumptionStmt *stmt) override { |
680 | // do nothing |
681 | } |
682 | |
683 | void visit(LinearizeStmt *stmt) override { |
684 | // do nothing |
685 | } |
686 | |
687 | void visit(IntegerOffsetStmt *stmt) override { |
688 | // do nothing |
689 | } |
690 | |
691 | void visit(RandStmt *stmt) override { |
692 | TI_ERROR("RandStmt not supported in AutoDiff for now." ); |
693 | } |
694 | }; |
695 | |
696 | // Generate the adjoint version of an independent block |
697 | class MakeAdjoint : public ADTransform { |
698 | public: |
699 | using ADTransform::visit; |
700 | Block *current_block; |
701 | Block *alloca_block; |
702 | // Backup the forward pass (the forward pass might be modified during the |
703 | // MakeAdjoint) for search whether a GlobalLoadStmt is inside a for-loop when |
704 | // allocating adjoint (see the function `adjoint`) Should be stored |
705 | // 1. Before entering a for-loop body |
706 | // 2. Before entering a if-stmt |
707 | // Should be restored after processing every statement in the two cases above |
708 | Block *forward_backup; |
709 | std::map<Stmt *, Stmt *> adjoint_stmt; |
710 | |
711 | explicit MakeAdjoint(Block *block) { |
712 | current_block = nullptr; |
713 | alloca_block = block; |
714 | forward_backup = block; |
715 | } |
716 | |
717 | static void run(Block *block) { |
718 | auto p = MakeAdjoint(block); |
719 | block->accept(&p); |
720 | } |
721 | |
722 | // TODO: current block might not be the right block to insert adjoint |
723 | // instructions! |
724 | void visit(Block *block) override { |
725 | std::vector<Stmt *> statements; |
726 | // always make a copy since the list can be modified. |
727 | for (auto &stmt : block->statements) { |
728 | statements.push_back(stmt.get()); |
729 | } |
730 | std::reverse(statements.begin(), statements.end()); // reverse-mode AD... |
731 | for (auto stmt : statements) { |
732 | current_block = block; |
733 | stmt->accept(this); |
734 | } |
735 | } |
736 | |
737 | Stmt *insert_grad_stmt(std::unique_ptr<Stmt> &&stmt) override { |
738 | auto ptr = stmt.get(); |
739 | current_block->insert(std::move(stmt), -1); |
740 | return ptr; |
741 | } |
742 | |
743 | // Accumulate [value] to the adjoint of [primal] |
744 | void accumulate(Stmt *primal, Stmt *value) { |
745 | auto alloca_ = adjoint(primal); |
746 | if (!alloca_ || alloca_->is<ConstStmt>()) |
747 | return; // primal may be int variable |
748 | if (alloca_->is<AdStackAllocaStmt>()) { |
749 | auto alloca = alloca_->cast<AdStackAllocaStmt>(); |
750 | if (is_real(alloca->ret_type)) { |
751 | insert<AdStackAccAdjointStmt>(alloca, load(value)); |
752 | } |
753 | } else { |
754 | TI_ASSERT(alloca_->is<AllocaStmt>()); |
755 | auto alloca = alloca_->as<AllocaStmt>(); |
756 | auto local_load = insert<LocalLoadStmt>(alloca); |
757 | insert<LocalStoreStmt>(alloca, add(local_load, value)); |
758 | } |
759 | } |
760 | |
761 | Stmt *adjoint(Stmt *stmt) { |
762 | if (!is_real(stmt->ret_type) || stmt->is<ConstStmt>()) { |
763 | return constant(0); |
764 | } |
765 | if (adjoint_stmt.find(stmt) == adjoint_stmt.end()) { |
766 | // normal SSA cases |
767 | |
768 | // create the alloca |
769 | // auto alloca = |
770 | // Stmt::make<AllocaStmt>(get_current_program().config.gradient_dt); |
771 | // maybe it's better to use the statement data type than the default type |
772 | auto alloca = Stmt::make<AllocaStmt>(stmt->ret_type); |
773 | adjoint_stmt[stmt] = alloca.get(); |
774 | |
775 | // We need to insert the alloca in the block of GlobalLoadStmt when the |
776 | // GlobalLoadStmt is not inside a range-for |
777 | // Code sample: |
778 | // a and b require grad |
779 | // Case 1 (GlobalLoadStmt is outside the for-loop, compute 5 times and |
780 | // accumulate once, alloca history value is needed): |
781 | // for i in range(5): |
782 | // p = a[i] |
783 | // q = b[i] |
784 | // for _ in range(5) |
785 | // q += p |
786 | |
787 | // Case 2 (GlobalLoadStmt is inside the for-loop, compute once and |
788 | // accumulate immediately, alloca history value can be discarded): |
789 | // for i in range(5): |
790 | // q = b[i] |
791 | // for _ in range(5) |
792 | // q += a[i] |
793 | if (stmt->is<GlobalLoadStmt>() && |
794 | (stmt->parent->parent_stmt != nullptr) && |
795 | stmt->parent->parent_stmt->is<RangeForStmt>()) { |
796 | // Check whether this GlobalLoadStmt is in the body of a for-loop by |
797 | // searching in the backup forward pass If not (Case 1), the alloca |
798 | // should not be clear every iteration, therefore, we need to insert the |
799 | // alloca in the block of the GlobalLoadStmt i.e., where GlobalLoadStmt |
800 | // is defined |
801 | if (forward_backup->locate(stmt->as<GlobalLoadStmt>()) == -1) { |
802 | stmt->as<GlobalLoadStmt>()->parent->insert(std::move(alloca), 0); |
803 | } else { |
804 | alloca_block->insert(std::move(alloca), 0); |
805 | } |
806 | } else { |
807 | alloca_block->insert(std::move(alloca), 0); |
808 | } |
809 | } |
810 | return adjoint_stmt[stmt]; |
811 | } |
812 | |
813 | void visit(UnaryOpStmt *stmt) override { |
814 | if (stmt->op_type == UnaryOpType::floor || |
815 | stmt->op_type == UnaryOpType::ceil) { |
816 | // do nothing |
817 | } else if (stmt->op_type == UnaryOpType::neg) { |
818 | accumulate(stmt->operand, negate(adjoint(stmt))); |
819 | } else if (stmt->op_type == UnaryOpType::abs) { |
820 | accumulate(stmt->operand, mul(adjoint(stmt), sgn(stmt->operand))); |
821 | } else if (stmt->op_type == UnaryOpType::sin) { |
822 | accumulate(stmt->operand, mul(adjoint(stmt), cos(stmt->operand))); |
823 | } else if (stmt->op_type == UnaryOpType::cos) { |
824 | accumulate(stmt->operand, negate(mul(adjoint(stmt), sin(stmt->operand)))); |
825 | } else if (stmt->op_type == UnaryOpType::tan) { |
826 | // The derivative of `tan` is `1 / cos^2`, which has many singular points |
827 | // causing NaNs. Though the NaNs are expected, it is error prone and hard |
828 | // to debug. Therefore we currently don't support computing derivative for |
829 | // `tan`. |
830 | TI_NOT_IMPLEMENTED; |
831 | } else if (stmt->op_type == UnaryOpType::tanh) { |
832 | accumulate(stmt->operand, |
833 | mul(adjoint(stmt), sub(constant(1), sqr(stmt)))); |
834 | } else if (stmt->op_type == UnaryOpType::asin) { |
835 | accumulate( |
836 | stmt->operand, |
837 | mul(adjoint(stmt), |
838 | div(constant(1), sqrt(sub(constant(1), sqr(stmt->operand)))))); |
839 | } else if (stmt->op_type == UnaryOpType::acos) { |
840 | accumulate(stmt->operand, |
841 | mul(adjoint(stmt), |
842 | negate(div(constant(1), |
843 | sqrt(sub(constant(1), sqr(stmt->operand))))))); |
844 | } else if (stmt->op_type == UnaryOpType::exp) { |
845 | accumulate(stmt->operand, mul(adjoint(stmt), stmt)); |
846 | } else if (stmt->op_type == UnaryOpType::log) { |
847 | accumulate(stmt->operand, div(adjoint(stmt), stmt->operand)); |
848 | } else if (stmt->op_type == UnaryOpType::sqrt) { |
849 | accumulate(stmt->operand, |
850 | mul(adjoint(stmt), div(constant(0.5f), sqrt(stmt->operand)))); |
851 | } else if (stmt->op_type == UnaryOpType::rsqrt) { |
852 | accumulate( |
853 | stmt->operand, |
854 | mul(adjoint(stmt), |
855 | mul(constant(-0.5f), pow(rsqrt(stmt->operand), constant(3))))); |
856 | } else if (stmt->op_type == UnaryOpType::cast_value) { |
857 | if (is_real(stmt->cast_type) && is_real(stmt->operand->ret_type)) { |
858 | accumulate(stmt->operand, adjoint(stmt)); |
859 | } |
860 | } else if (stmt->op_type == UnaryOpType::logic_not) { |
861 | // do nothing |
862 | } else { |
863 | TI_P(unary_op_type_name(stmt->op_type)); |
864 | TI_NOT_IMPLEMENTED; |
865 | } |
866 | } |
867 | |
868 | void visit(BinaryOpStmt *bin) override { |
869 | if (bin->op_type == BinaryOpType::add) { |
870 | accumulate(bin->lhs, adjoint(bin)); |
871 | accumulate(bin->rhs, adjoint(bin)); |
872 | } else if (bin->op_type == BinaryOpType::sub) { |
873 | accumulate(bin->lhs, adjoint(bin)); |
874 | accumulate(bin->rhs, negate(adjoint(bin))); |
875 | } else if (bin->op_type == BinaryOpType::mul) { |
876 | // d (x * y) = y * dx + x * dy |
877 | accumulate(bin->lhs, mul(adjoint(bin), bin->rhs)); |
878 | accumulate(bin->rhs, mul(adjoint(bin), bin->lhs)); |
879 | } else if (bin->op_type == BinaryOpType::mod) { |
880 | // Do nothing |
881 | } else if (bin->op_type == BinaryOpType::div) { |
882 | accumulate(bin->lhs, div(adjoint(bin), bin->rhs)); |
883 | accumulate(bin->rhs, negate(div(mul(adjoint(bin), bin->lhs), |
884 | mul(bin->rhs, bin->rhs)))); |
885 | } else if (bin->op_type == BinaryOpType::atan2) { |
886 | auto numerator = add(sqr(bin->lhs), sqr(bin->rhs)); |
887 | accumulate(bin->lhs, div(mul(adjoint(bin), bin->rhs), numerator)); |
888 | accumulate(bin->rhs, negate(div(mul(adjoint(bin), bin->lhs), numerator))); |
889 | } else if (bin->op_type == BinaryOpType::pow) { |
890 | // d (x ^ y) = x ^ (y-1) * (y * dx + log(x) * x * dy) |
891 | auto common_coeff = |
892 | pow(bin->lhs, sub(bin->rhs, constant(1))); // x ^ (y-1) |
893 | accumulate(bin->lhs, mul(adjoint(bin), mul(bin->rhs, common_coeff))); |
894 | accumulate(bin->rhs, mul(adjoint(bin), mul(log(bin->lhs), |
895 | mul(bin->lhs, common_coeff)))); |
896 | } else if (bin->op_type == BinaryOpType::min || |
897 | bin->op_type == BinaryOpType::max) { |
898 | auto cmp = bin->op_type == BinaryOpType::min ? cmp_lt(bin->lhs, bin->rhs) |
899 | : cmp_lt(bin->rhs, bin->lhs); |
900 | auto zero = insert<ConstStmt>(TypedConstant(bin->ret_type)); |
901 | accumulate(bin->lhs, sel(cmp, adjoint(bin), zero)); |
902 | accumulate(bin->rhs, sel(cmp, zero, adjoint(bin))); |
903 | } else if (bin->op_type == BinaryOpType::floordiv) { |
904 | // do nothing |
905 | } else if (is_comparison(bin->op_type) || is_bit_op(bin->op_type)) { |
906 | // do nothing |
907 | } else { |
908 | TI_WARN("gradient of binary op {}\n{}" , binary_op_type_name(bin->op_type), |
909 | bin->tb); |
910 | TI_NOT_IMPLEMENTED; |
911 | } |
912 | } |
913 | |
914 | void visit(TernaryOpStmt *stmt) override { |
915 | TI_ASSERT(stmt->op_type == TernaryOpType::select); |
916 | auto zero = insert<ConstStmt>(TypedConstant(stmt->ret_type)); |
917 | accumulate(stmt->op2, |
918 | insert<TernaryOpStmt>(TernaryOpType::select, stmt->op1, |
919 | load(adjoint(stmt)), zero)); |
920 | accumulate(stmt->op3, |
921 | insert<TernaryOpStmt>(TernaryOpType::select, stmt->op1, zero, |
922 | load(adjoint(stmt)))); |
923 | } |
924 | |
925 | void visit(IfStmt *if_stmt) override { |
926 | auto new_if = Stmt::make_typed<IfStmt>(if_stmt->cond); |
927 | if (if_stmt->true_statements) { |
928 | new_if->set_true_statements(std::make_unique<Block>()); |
929 | auto old_current_block = current_block; |
930 | // Backup forward pass |
931 | forward_backup = if_stmt->true_statements.get(); |
932 | |
933 | current_block = new_if->true_statements.get(); |
934 | for (int i = if_stmt->true_statements->statements.size() - 1; i >= 0; |
935 | i--) { |
936 | if_stmt->true_statements->statements[i]->accept(this); |
937 | // Restore forward pass |
938 | forward_backup = if_stmt->true_statements.get(); |
939 | } |
940 | |
941 | current_block = old_current_block; |
942 | } |
943 | if (if_stmt->false_statements) { |
944 | new_if->set_false_statements(std::make_unique<Block>()); |
945 | auto old_current_block = current_block; |
946 | |
947 | // Backup forward pass |
948 | forward_backup = if_stmt->false_statements.get(); |
949 | |
950 | current_block = new_if->false_statements.get(); |
951 | for (int i = if_stmt->false_statements->statements.size() - 1; i >= 0; |
952 | i--) { |
953 | if_stmt->false_statements->statements[i]->accept(this); |
954 | // Restore forward pass |
955 | forward_backup = if_stmt->false_statements.get(); |
956 | } |
957 | current_block = old_current_block; |
958 | } |
959 | insert_grad_stmt(std::move(new_if)); |
960 | } |
961 | |
962 | void visit(RangeForStmt *for_stmt) override { |
963 | auto new_for = for_stmt->clone(); |
964 | auto new_for_ptr = new_for->as<RangeForStmt>(); |
965 | new_for_ptr->reversed = !new_for_ptr->reversed; |
966 | insert_grad_stmt(std::move(new_for)); |
967 | const int len = new_for_ptr->body->size(); |
968 | |
969 | for (int i = 0; i < len; i++) { |
970 | new_for_ptr->body->erase(0); |
971 | } |
972 | |
973 | std::vector<Stmt *> statements; |
974 | // always make a copy since the list can be modified. |
975 | for (auto &stmt : for_stmt->body->statements) { |
976 | statements.push_back(stmt.get()); |
977 | } |
978 | std::reverse(statements.begin(), statements.end()); // reverse-mode AD... |
979 | auto old_alloca_block = alloca_block; |
980 | auto old_forward_backup = |
981 | forward_backup; // store the block which is not inside the current IB, |
982 | // such as outer most loop |
983 | // Backup the forward pass |
984 | forward_backup = for_stmt->body.get(); |
985 | for (auto stmt : statements) { |
986 | alloca_block = new_for_ptr->body.get(); |
987 | current_block = new_for_ptr->body.get(); |
988 | stmt->accept(this); |
989 | // Restore the forward pass |
990 | forward_backup = for_stmt->body.get(); |
991 | } |
992 | forward_backup = old_forward_backup; |
993 | alloca_block = old_alloca_block; |
994 | } |
995 | |
996 | void visit(StructForStmt *for_stmt) override { |
997 | alloca_block = for_stmt->body.get(); |
998 | for_stmt->body->accept(this); |
999 | } |
1000 | |
1001 | // Equivalent to AdStackLoadTopStmt when no stack is needed |
1002 | void visit(LocalLoadStmt *stmt) override { |
1003 | // TI_ASSERT(!needs_grad(stmt->ret_type)); |
1004 | if (is_real(stmt->ret_type)) |
1005 | accumulate(stmt->src, load(adjoint(stmt))); |
1006 | } |
1007 | |
1008 | // Equivalent to AdStackPushStmt when no stack is needed |
1009 | void visit(LocalStoreStmt *stmt) override { |
1010 | accumulate(stmt->val, load(adjoint(stmt->dest))); |
1011 | |
1012 | // Clear the adjoint of the dest after local store, |
1013 | // Because LocalStoreStmt overwrites the dest, |
1014 | // 1. If the alloca is inside a loop, the adjoint of this alloca of this |
1015 | // iteration should be cleared after this iteration has been done |
1016 | // 2. If the alloca serves as the dest of multiple LocalStoreStmt, only the |
1017 | // last LocalStoreStmt should be taken account of |
1018 | if (is_real(stmt->dest->ret_type)) { |
1019 | auto dtype = stmt->dest->ret_type; |
1020 | auto zero = insert<ConstStmt>(TypedConstant(dtype, 0)); |
1021 | insert<LocalStoreStmt>(adjoint(stmt->dest), zero); |
1022 | } |
1023 | } |
1024 | |
1025 | void visit(AdStackLoadTopStmt *stmt) override { |
1026 | if (is_real(stmt->ret_type)) |
1027 | insert<AdStackAccAdjointStmt>(stmt->stack, load(adjoint(stmt))); |
1028 | } |
1029 | |
1030 | void visit(AdStackPushStmt *stmt) override { |
1031 | accumulate(stmt->v, insert<AdStackLoadTopAdjStmt>(stmt->stack)); |
1032 | insert<AdStackPopStmt>(stmt->stack); |
1033 | } |
1034 | |
1035 | void visit(GlobalLoadStmt *stmt) override { |
1036 | // issue global store to adjoint |
1037 | if (stmt->src->is<ExternalPtrStmt>()) { |
1038 | TI_ERROR( |
1039 | "Importing data from external array (such as numpy array) not " |
1040 | "supported in AutoDiff for now" ) |
1041 | } |
1042 | |
1043 | GlobalPtrStmt *src = nullptr; |
1044 | bool is_ptr_offset = false; |
1045 | if (stmt->src->is<MatrixPtrStmt>()) { |
1046 | is_ptr_offset = true; |
1047 | src = stmt->src->as<MatrixPtrStmt>()->origin->as<GlobalPtrStmt>(); |
1048 | } else { |
1049 | src = stmt->src->as<GlobalPtrStmt>(); |
1050 | } |
1051 | |
1052 | auto snode = src->snode; |
1053 | if (!snode->has_adjoint()) { |
1054 | // No adjoint SNode. Do nothing |
1055 | return; |
1056 | } |
1057 | if (gradients_stopped(stmt, snode)) { |
1058 | // gradients stopped, do nothing. |
1059 | return; |
1060 | } |
1061 | TI_ASSERT(snode->get_adjoint() != nullptr); |
1062 | snode = snode->get_adjoint(); |
1063 | auto adj_ptr = insert<GlobalPtrStmt>(snode, src->indices); |
1064 | if (is_ptr_offset) { |
1065 | adj_ptr = insert<MatrixPtrStmt>(adj_ptr, |
1066 | stmt->src->as<MatrixPtrStmt>()->offset); |
1067 | } |
1068 | insert<AtomicOpStmt>(AtomicOpType::add, adj_ptr, load(adjoint(stmt))); |
1069 | } |
1070 | |
1071 | void visit(GlobalStoreStmt *stmt) override { |
1072 | // erase and replace with global load adjoint |
1073 | if (stmt->dest->is<ExternalPtrStmt>()) { |
1074 | TI_ERROR( |
1075 | "Exporting data to external array (such as numpy array) not " |
1076 | "supported in AutoDiff for now" ) |
1077 | } |
1078 | |
1079 | GlobalPtrStmt *dest = nullptr; |
1080 | bool is_ptr_offset = false; |
1081 | if (stmt->dest->is<MatrixPtrStmt>()) { |
1082 | is_ptr_offset = true; |
1083 | dest = stmt->dest->as<MatrixPtrStmt>()->origin->as<GlobalPtrStmt>(); |
1084 | } else { |
1085 | dest = stmt->dest->as<GlobalPtrStmt>(); |
1086 | } |
1087 | |
1088 | auto snode = dest->snode; |
1089 | if (!snode->has_adjoint()) { |
1090 | // no gradient (likely integer types) |
1091 | return; |
1092 | } |
1093 | TI_ASSERT(snode->get_adjoint() != nullptr); |
1094 | snode = snode->get_adjoint(); |
1095 | auto adjoint_ptr = insert<GlobalPtrStmt>(snode, dest->indices); |
1096 | if (is_ptr_offset) { |
1097 | adjoint_ptr = insert<MatrixPtrStmt>( |
1098 | adjoint_ptr, stmt->dest->as<MatrixPtrStmt>()->offset); |
1099 | } |
1100 | accumulate(stmt->val, insert<GlobalLoadStmt>(adjoint_ptr)); |
1101 | |
1102 | // Clear the gradient after accumulation finished. |
1103 | auto zero = insert<ConstStmt>( |
1104 | TypedConstant(adjoint_ptr->ret_type.ptr_removed(), 0)); |
1105 | insert<GlobalStoreStmt>(adjoint_ptr, zero); |
1106 | |
1107 | stmt->parent->erase(stmt); |
1108 | } |
1109 | |
1110 | void visit(AtomicOpStmt *stmt) override { |
1111 | // erase and replace with global load adjoint |
1112 | GlobalPtrStmt *dest = nullptr; |
1113 | bool is_ptr_offset = false; |
1114 | if (stmt->dest->is<MatrixPtrStmt>()) { |
1115 | is_ptr_offset = true; |
1116 | dest = stmt->dest->as<MatrixPtrStmt>()->origin->as<GlobalPtrStmt>(); |
1117 | } else { |
1118 | dest = stmt->dest->as<GlobalPtrStmt>(); |
1119 | } |
1120 | |
1121 | auto snode = dest->snode; |
1122 | if (!snode->has_adjoint()) { |
1123 | // no gradient (likely integer types) |
1124 | return; |
1125 | } |
1126 | |
1127 | TI_ASSERT(snode->get_adjoint() != nullptr); |
1128 | snode = snode->get_adjoint(); |
1129 | auto adjoint_ptr = insert<GlobalPtrStmt>(snode, dest->indices); |
1130 | if (is_ptr_offset) { |
1131 | adjoint_ptr = insert<MatrixPtrStmt>( |
1132 | adjoint_ptr, stmt->dest->as<MatrixPtrStmt>()->offset); |
1133 | } |
1134 | accumulate(stmt->val, insert<GlobalLoadStmt>(adjoint_ptr)); |
1135 | stmt->parent->erase(stmt); |
1136 | } |
1137 | }; |
1138 | |
1139 | // Forward mode autodiff |
1140 | class MakeDual : public ADTransform { |
1141 | public: |
1142 | using ADTransform::visit; |
1143 | Stmt *current_stmt; |
1144 | Block *current_block; |
1145 | Block *alloca_block; |
1146 | std::map<Stmt *, Stmt *> dual_stmt; |
1147 | |
1148 | explicit MakeDual(Block *block) { |
1149 | current_stmt = nullptr; |
1150 | alloca_block = block; |
1151 | current_block = block; |
1152 | } |
1153 | |
1154 | static void run(Block *block) { |
1155 | auto p = MakeDual(block); |
1156 | block->accept(&p); |
1157 | } |
1158 | |
1159 | Stmt *insert_grad_stmt(std::unique_ptr<Stmt> &&stmt) override { |
1160 | auto ptr = stmt.get(); |
1161 | current_stmt = current_stmt->insert_after_me(std::move(stmt)); |
1162 | return ptr; |
1163 | } |
1164 | |
1165 | void visit(Block *block) override { |
1166 | std::vector<Stmt *> statements; |
1167 | // always make a copy since the list can be modified. |
1168 | for (auto &stmt : block->statements) { |
1169 | statements.push_back(stmt.get()); |
1170 | } |
1171 | for (auto stmt : statements) { |
1172 | current_stmt = stmt; |
1173 | stmt->accept(this); |
1174 | } |
1175 | } |
1176 | |
1177 | // Accumulate [value] to the dual of [primal] |
1178 | void accumulate(Stmt *primal, Stmt *value) { |
1179 | auto alloca_ = dual(primal); |
1180 | if (!alloca_ || alloca_->is<ConstStmt>()) |
1181 | return; // primal may be int variable |
1182 | |
1183 | TI_ASSERT(alloca_->is<AllocaStmt>()); |
1184 | auto alloca = alloca_->as<AllocaStmt>(); |
1185 | auto local_load = insert<LocalLoadStmt>(alloca); |
1186 | insert<LocalStoreStmt>(alloca, add(local_load, value)); |
1187 | } |
1188 | |
1189 | Stmt *dual(Stmt *stmt) { |
1190 | if (!is_real(stmt->ret_type) || stmt->is<ConstStmt>()) { |
1191 | return constant(0); |
1192 | } |
1193 | if (dual_stmt.find(stmt) == dual_stmt.end()) { |
1194 | // normal SSA cases |
1195 | |
1196 | // create the alloca |
1197 | // auto alloca = |
1198 | // Stmt::make<AllocaStmt>(get_current_program().config.gradient_dt); |
1199 | // maybe it's better to use the statement data type than the default type |
1200 | auto alloca = Stmt::make<AllocaStmt>(stmt->ret_type); |
1201 | dual_stmt[stmt] = alloca.get(); |
1202 | |
1203 | // TODO: check whether there are any edge cases for the alloca_block |
1204 | alloca_block->insert(std::move(alloca), 0); |
1205 | } |
1206 | return dual_stmt[stmt]; |
1207 | } |
1208 | |
1209 | void visit(UnaryOpStmt *stmt) override { |
1210 | if (stmt->op_type == UnaryOpType::neg) { |
1211 | accumulate(stmt, negate(dual(stmt->operand))); |
1212 | } else if (stmt->op_type == UnaryOpType::abs) { |
1213 | accumulate(stmt, mul(sgn(stmt->operand), dual(stmt->operand))); |
1214 | } else if (stmt->op_type == UnaryOpType::sin) { |
1215 | accumulate(stmt, mul(cos(stmt->operand), dual(stmt->operand))); |
1216 | } else if (stmt->op_type == UnaryOpType::cos) { |
1217 | accumulate(stmt, negate(mul(sin(stmt->operand), dual(stmt->operand)))); |
1218 | } else if (stmt->op_type == UnaryOpType::tan) { |
1219 | // The derivative of `tan` is `1 / cos^2`, which has many singular points |
1220 | // causing NaNs. Though the NaNs are expected, it is error prone and hard |
1221 | // to debug. Therefore we currently don't support computing derivative for |
1222 | // `tan`. |
1223 | TI_NOT_IMPLEMENTED; |
1224 | } else if (stmt->op_type == UnaryOpType::tanh) { |
1225 | accumulate(stmt, mul(sub(constant(1), sqr(stmt)), dual(stmt->operand))); |
1226 | } else if (stmt->op_type == UnaryOpType::asin) { |
1227 | accumulate(stmt, mul(div(constant(1), |
1228 | sqrt(sub(constant(1), sqr(stmt->operand)))), |
1229 | dual(stmt->operand))); |
1230 | } else if (stmt->op_type == UnaryOpType::acos) { |
1231 | accumulate(stmt, |
1232 | mul(negate(div(constant(1), |
1233 | sqrt(sub(constant(1), sqr(stmt->operand))))), |
1234 | dual(stmt->operand))); |
1235 | } else if (stmt->op_type == UnaryOpType::exp) { |
1236 | accumulate(stmt, mul(stmt, dual(stmt->operand))); |
1237 | } else if (stmt->op_type == UnaryOpType::log) { |
1238 | accumulate(stmt, div(dual(stmt->operand), stmt->operand)); |
1239 | } else if (stmt->op_type == UnaryOpType::sqrt) { |
1240 | accumulate(stmt, mul(div(constant(0.5f), sqrt(stmt->operand)), |
1241 | dual(stmt->operand))); |
1242 | } else if (stmt->op_type == UnaryOpType::rsqrt) { |
1243 | accumulate(stmt, mul(mul(constant(-0.5f), |
1244 | pow(rsqrt(stmt->operand), constant(3))), |
1245 | dual(stmt->operand))); |
1246 | } else if (stmt->op_type == UnaryOpType::cast_value) { |
1247 | if (is_real(stmt->cast_type) && is_real(stmt->operand->ret_type)) { |
1248 | accumulate(stmt, dual(stmt->operand)); |
1249 | } |
1250 | } else if (stmt->op_type == UnaryOpType::logic_not) { |
1251 | // do nothing |
1252 | } else { |
1253 | TI_P(unary_op_type_name(stmt->op_type)); |
1254 | TI_NOT_IMPLEMENTED |
1255 | } |
1256 | } |
1257 | |
1258 | void visit(BinaryOpStmt *bin) override { |
1259 | if (bin->op_type == BinaryOpType::add) { |
1260 | accumulate(bin, dual(bin->lhs)); |
1261 | accumulate(bin, dual(bin->rhs)); |
1262 | } else if (bin->op_type == BinaryOpType::sub) { |
1263 | accumulate(bin, dual(bin->lhs)); |
1264 | accumulate(bin, negate(dual(bin->rhs))); |
1265 | } else if (bin->op_type == BinaryOpType::mul) { |
1266 | // d (x * y) = y * dx + x * dy |
1267 | accumulate(bin, mul(bin->lhs, dual(bin->rhs))); |
1268 | accumulate(bin, mul(bin->rhs, dual(bin->lhs))); |
1269 | } else if (bin->op_type == BinaryOpType::mod) { |
1270 | // Do nothing |
1271 | } else if (bin->op_type == BinaryOpType::div) { |
1272 | accumulate(bin, div(dual(bin->lhs), bin->rhs)); |
1273 | accumulate(bin, negate(div(mul(dual(bin->rhs), bin->lhs), |
1274 | mul(bin->rhs, bin->rhs)))); |
1275 | } else if (bin->op_type == BinaryOpType::atan2) { |
1276 | auto numerator = add(sqr(bin->lhs), sqr(bin->rhs)); |
1277 | accumulate(bin, div(mul(bin->rhs, dual(bin->lhs)), numerator)); |
1278 | accumulate(bin, negate(div(mul(bin->lhs, dual(bin->rhs)), numerator))); |
1279 | } else if (bin->op_type == BinaryOpType::pow) { |
1280 | // d (x ^ y) = x ^ (y-1) * (y * dx + log(x) * x * dy) |
1281 | auto common_coeff = |
1282 | pow(bin->lhs, sub(bin->rhs, constant(1))); // x ^ (y-1) |
1283 | accumulate(bin, mul(dual(bin->lhs), mul(bin->rhs, common_coeff))); |
1284 | accumulate(bin, mul(dual(bin->rhs), |
1285 | mul(log(bin->lhs), mul(bin->lhs, common_coeff)))); |
1286 | } else if (bin->op_type == BinaryOpType::min || |
1287 | bin->op_type == BinaryOpType::max) { |
1288 | auto cmp = bin->op_type == BinaryOpType::min ? cmp_lt(bin->lhs, bin->rhs) |
1289 | : cmp_lt(bin->rhs, bin->lhs); |
1290 | auto zero = insert<ConstStmt>(TypedConstant(bin->ret_type)); |
1291 | accumulate(bin, sel(cmp, dual(bin->lhs), zero)); |
1292 | accumulate(bin, sel(cmp, zero, dual(bin->rhs))); |
1293 | } else if (bin->op_type == BinaryOpType::floordiv) { |
1294 | // do nothing |
1295 | } else if (is_comparison(bin->op_type) || is_bit_op(bin->op_type)) { |
1296 | // do nothing |
1297 | } else { |
1298 | TI_WARN("gradient of binary op {}\n{}" , binary_op_type_name(bin->op_type), |
1299 | bin->tb); |
1300 | TI_NOT_IMPLEMENTED |
1301 | } |
1302 | } |
1303 | |
1304 | void visit(TernaryOpStmt *stmt) override { |
1305 | TI_ASSERT(stmt->op_type == TernaryOpType::select); |
1306 | auto zero = insert<ConstStmt>(TypedConstant(stmt->ret_type)); |
1307 | accumulate(stmt, insert<TernaryOpStmt>(TernaryOpType::select, stmt->op1, |
1308 | load(dual(stmt->op2)), zero)); |
1309 | accumulate(stmt, insert<TernaryOpStmt>(TernaryOpType::select, stmt->op1, |
1310 | zero, load(dual(stmt->op3)))); |
1311 | } |
1312 | |
1313 | void visit(IfStmt *if_stmt) override { |
1314 | if (if_stmt->true_statements) { |
1315 | std::vector<Stmt *> true_statements; |
1316 | for (auto &stmt : if_stmt->true_statements->statements) { |
1317 | true_statements.push_back(stmt.get()); |
1318 | } |
1319 | |
1320 | for (auto stmt : true_statements) { |
1321 | current_stmt = stmt; |
1322 | stmt->accept(this); |
1323 | } |
1324 | } |
1325 | if (if_stmt->false_statements) { |
1326 | std::vector<Stmt *> false_statements; |
1327 | for (auto &stmt : if_stmt->false_statements->statements) { |
1328 | false_statements.push_back(stmt.get()); |
1329 | } |
1330 | |
1331 | for (auto stmt : false_statements) { |
1332 | current_stmt = stmt; |
1333 | stmt->accept(this); |
1334 | } |
1335 | } |
1336 | } |
1337 | |
1338 | void visit(RangeForStmt *for_stmt) override { |
1339 | std::vector<Stmt *> statements; |
1340 | // always make a copy since the list can be modified. |
1341 | for (auto &stmt : for_stmt->body->statements) { |
1342 | statements.push_back(stmt.get()); |
1343 | } |
1344 | auto previous_alloca_block = alloca_block; |
1345 | alloca_block = for_stmt->body.get(); |
1346 | for (auto stmt : statements) { |
1347 | current_stmt = stmt; |
1348 | stmt->accept(this); |
1349 | } |
1350 | alloca_block = previous_alloca_block; |
1351 | } |
1352 | |
1353 | void visit(StructForStmt *for_stmt) override { |
1354 | alloca_block = for_stmt->body.get(); |
1355 | for_stmt->body->accept(this); |
1356 | } |
1357 | |
1358 | void visit(LocalLoadStmt *stmt) override { |
1359 | // TI_ASSERT(!needs_grad(stmt->ret_type)); |
1360 | accumulate(stmt, dual(stmt->src)); |
1361 | } |
1362 | |
1363 | void visit(LocalStoreStmt *stmt) override { |
1364 | // Clear the dual of the dest before local store, |
1365 | // Because LocalStoreStmt overwrites the dest, |
1366 | // If the alloca serves as the dest of multiple LocalStoreStmt, only the |
1367 | // last LocalStoreStmt should be taken account of, i.e, its history should |
1368 | // be cleared |
1369 | if (is_real(stmt->dest->ret_type)) { |
1370 | auto dtype = stmt->dest->ret_type; |
1371 | auto zero = insert<ConstStmt>(TypedConstant(dtype, 0)); |
1372 | insert<LocalStoreStmt>(dual(stmt->dest), zero); |
1373 | } |
1374 | |
1375 | accumulate(stmt->dest, dual(stmt->val)); |
1376 | } |
1377 | |
1378 | void visit(GlobalLoadStmt *stmt) override { |
1379 | // issue global store to dual |
1380 | GlobalPtrStmt *src = nullptr; |
1381 | bool is_ptr_offset = false; |
1382 | if (stmt->src->is<MatrixPtrStmt>()) { |
1383 | is_ptr_offset = true; |
1384 | src = stmt->src->as<MatrixPtrStmt>()->origin->as<GlobalPtrStmt>(); |
1385 | } else { |
1386 | src = stmt->src->as<GlobalPtrStmt>(); |
1387 | } |
1388 | auto snode = src->snode; |
1389 | if (!snode->has_dual()) { |
1390 | // No dual SNode. Do nothing |
1391 | return; |
1392 | } |
1393 | if (gradients_stopped(stmt, snode)) { |
1394 | // gradients stopped, do nothing. |
1395 | return; |
1396 | } |
1397 | TI_ASSERT(snode->get_dual() != nullptr); |
1398 | snode = snode->get_dual(); |
1399 | auto dual_ptr = insert<GlobalPtrStmt>(snode, src->indices); |
1400 | if (is_ptr_offset) { |
1401 | dual_ptr = insert<MatrixPtrStmt>(dual_ptr, |
1402 | stmt->src->as<MatrixPtrStmt>()->offset); |
1403 | } |
1404 | accumulate(stmt, insert<GlobalLoadStmt>(dual_ptr)); |
1405 | } |
1406 | |
1407 | void visit(GlobalStoreStmt *stmt) override { |
1408 | GlobalPtrStmt *dest = nullptr; |
1409 | bool is_ptr_offset = false; |
1410 | if (stmt->dest->is<MatrixPtrStmt>()) { |
1411 | is_ptr_offset = true; |
1412 | dest = stmt->dest->as<MatrixPtrStmt>()->origin->as<GlobalPtrStmt>(); |
1413 | } else { |
1414 | dest = stmt->dest->as<GlobalPtrStmt>(); |
1415 | } |
1416 | auto snode = dest->snode; |
1417 | if (!snode->has_dual()) { |
1418 | // no gradient (likely integer types) |
1419 | return; |
1420 | } |
1421 | TI_ASSERT(snode->get_dual() != nullptr); |
1422 | snode = snode->get_dual(); |
1423 | auto dual_ptr = insert<GlobalPtrStmt>(snode, dest->indices); |
1424 | if (is_ptr_offset) { |
1425 | dual_ptr = insert<MatrixPtrStmt>(dual_ptr, |
1426 | stmt->dest->as<MatrixPtrStmt>()->offset); |
1427 | } |
1428 | insert<AtomicOpStmt>(AtomicOpType::add, dual_ptr, load(dual(stmt->val))); |
1429 | } |
1430 | |
1431 | void visit(AtomicOpStmt *stmt) override { |
1432 | GlobalPtrStmt *dest = nullptr; |
1433 | bool is_ptr_offset = false; |
1434 | if (stmt->dest->is<MatrixPtrStmt>()) { |
1435 | is_ptr_offset = true; |
1436 | dest = stmt->dest->as<MatrixPtrStmt>()->origin->as<GlobalPtrStmt>(); |
1437 | } else { |
1438 | dest = stmt->dest->as<GlobalPtrStmt>(); |
1439 | } |
1440 | auto snode = dest->snode; |
1441 | if (!snode->has_dual()) { |
1442 | // no gradient (likely integer types) |
1443 | return; |
1444 | } |
1445 | TI_ASSERT(snode->get_dual() != nullptr); |
1446 | snode = snode->get_dual(); |
1447 | auto dual_ptr = insert<GlobalPtrStmt>(snode, dest->indices); |
1448 | if (is_ptr_offset) { |
1449 | dual_ptr = insert<MatrixPtrStmt>(dual_ptr, |
1450 | stmt->dest->as<MatrixPtrStmt>()->offset); |
1451 | } |
1452 | insert<AtomicOpStmt>(AtomicOpType::add, dual_ptr, load(dual(stmt->val))); |
1453 | } |
1454 | }; |
1455 | |
1456 | class BackupSSA : public BasicStmtVisitor { |
1457 | public: |
1458 | using BasicStmtVisitor::visit; |
1459 | |
1460 | Block *independent_block; |
1461 | std::map<Stmt *, Stmt *> backup_alloca; |
1462 | |
1463 | explicit BackupSSA(Block *independent_block) |
1464 | : independent_block(independent_block) { |
1465 | allow_undefined_visitor = true; |
1466 | invoke_default_visitor = true; |
1467 | } |
1468 | |
1469 | Stmt *load(Stmt *stmt) { |
1470 | if (backup_alloca.find(stmt) == backup_alloca.end()) { |
1471 | auto alloca = Stmt::make<AllocaStmt>(stmt->ret_type); |
1472 | auto alloca_ptr = alloca.get(); |
1473 | independent_block->insert(std::move(alloca), 0); |
1474 | auto local_store = Stmt::make<LocalStoreStmt>(alloca_ptr, stmt); |
1475 | stmt->insert_after_me(std::move(local_store)); |
1476 | backup_alloca[stmt] = alloca_ptr; |
1477 | } |
1478 | return backup_alloca[stmt]; |
1479 | } |
1480 | |
1481 | void generic_visit(Stmt *stmt) { |
1482 | std::vector<Block *> leaf_to_root; |
1483 | auto t = stmt->parent; |
1484 | while (t != nullptr) { |
1485 | leaf_to_root.push_back(t); |
1486 | t = t->parent_block(); |
1487 | } |
1488 | int num_operands = stmt->get_operands().size(); |
1489 | for (int i = 0; i < num_operands; i++) { |
1490 | auto op = stmt->operand(i); |
1491 | if (op == nullptr) { |
1492 | continue; |
1493 | } |
1494 | if (std::find(leaf_to_root.begin(), leaf_to_root.end(), op->parent) == |
1495 | leaf_to_root.end() && |
1496 | !op->is<AllocaStmt>()) { |
1497 | if (op->is<AdStackLoadTopStmt>()) { |
1498 | // Just create another AdStackLoadTopStmt |
1499 | stmt->set_operand(i, stmt->insert_before_me(op->clone())); |
1500 | } else if (op->is<AdStackAllocaStmt>()) { |
1501 | // Backup AdStackAllocaStmt because it should not be local stored and |
1502 | // local loaded |
1503 | auto stack_alloca = op->as<AdStackAllocaStmt>(); |
1504 | if (backup_alloca.find(op) == backup_alloca.end()) { |
1505 | auto backup_stack_alloca = Stmt::make<AdStackAllocaStmt>( |
1506 | stack_alloca->dt, stack_alloca->max_size); |
1507 | auto backup_stack_alloca_ptr = backup_stack_alloca.get(); |
1508 | independent_block->insert(std::move(backup_stack_alloca), 0); |
1509 | backup_alloca[op] = backup_stack_alloca_ptr; |
1510 | // Replace usages of all blocks i.e., the entry point for the |
1511 | // replace is the top level block |
1512 | irpass::replace_all_usages_with(leaf_to_root.back(), op, |
1513 | backup_stack_alloca_ptr); |
1514 | // Erase the outdated AdStackAllocaStmt |
1515 | op->parent->erase(op); |
1516 | } |
1517 | } else { |
1518 | auto alloca = load(op); |
1519 | stmt->set_operand( |
1520 | i, stmt->insert_before_me(Stmt::make<LocalLoadStmt>(alloca))); |
1521 | } |
1522 | } |
1523 | } |
1524 | } |
1525 | |
1526 | void visit(Stmt *stmt) override { |
1527 | generic_visit(stmt); |
1528 | } |
1529 | |
1530 | void visit(IfStmt *stmt) override { |
1531 | generic_visit(stmt); |
1532 | BasicStmtVisitor::visit(stmt); |
1533 | } |
1534 | |
1535 | // TODO: test operands for statements |
1536 | void visit(RangeForStmt *stmt) override { |
1537 | stmt->body->accept(this); |
1538 | } |
1539 | |
1540 | void visit(StructForStmt *stmt) override { |
1541 | stmt->body->accept(this); |
1542 | } |
1543 | |
1544 | void visit(WhileStmt *stmt) override { |
1545 | TI_ERROR("WhileStmt not supported in AutoDiff for now." ); |
1546 | } |
1547 | |
1548 | void visit(Block *block) override { |
1549 | std::vector<Stmt *> statements; |
1550 | // always make a copy since the list can be modified. |
1551 | for (auto &stmt : block->statements) { |
1552 | statements.push_back(stmt.get()); |
1553 | } |
1554 | for (auto stmt : statements) { |
1555 | TI_ASSERT(!stmt->erased); |
1556 | stmt->accept(this); |
1557 | } |
1558 | } |
1559 | |
1560 | public: |
1561 | static void run(Block *block) { |
1562 | BackupSSA pass(block); |
1563 | block->accept(&pass); |
1564 | } |
1565 | }; |
1566 | |
1567 | namespace irpass { |
1568 | |
1569 | void auto_diff(IRNode *root, |
1570 | const CompileConfig &config, |
1571 | AutodiffMode autodiff_mode, |
1572 | bool use_stack) { |
1573 | TI_AUTO_PROF; |
1574 | if (autodiff_mode == AutodiffMode::kReverse) { |
1575 | if (use_stack) { |
1576 | auto IB = IdentifyIndependentBlocks::run(root); |
1577 | ReverseOuterLoops::run(root, IB); |
1578 | |
1579 | for (auto ib : IB) { |
1580 | PromoteSSA2LocalVar::run(ib); |
1581 | ReplaceLocalVarWithStacks replace(config.ad_stack_size); |
1582 | ib->accept(&replace); |
1583 | type_check(root, config); |
1584 | MakeAdjoint::run(ib); |
1585 | type_check(root, config); |
1586 | BackupSSA::run(ib); |
1587 | irpass::analysis::verify(root); |
1588 | } |
1589 | } else { |
1590 | auto IB = IdentifyIndependentBlocks::run(root); |
1591 | ReverseOuterLoops::run(root, IB); |
1592 | type_check(root, config); |
1593 | for (auto ib : IB) { |
1594 | MakeAdjoint::run(ib); |
1595 | } |
1596 | } |
1597 | } else if (autodiff_mode == AutodiffMode::kForward) { |
1598 | // Forward mode autodiff |
1599 | Block *block = root->as<Block>(); |
1600 | MakeDual::run(block); |
1601 | } |
1602 | type_check(root, config); |
1603 | irpass::analysis::verify(root); |
1604 | } |
1605 | |
1606 | class GloablDataAccessRuleChecker : public BasicStmtVisitor { |
1607 | public: |
1608 | using BasicStmtVisitor::visit; |
1609 | |
1610 | void visit(GlobalLoadStmt *stmt) override { |
1611 | GlobalPtrStmt *src = stmt->src->as<GlobalPtrStmt>(); |
1612 | auto snode = src->snode; |
1613 | if (!snode->has_adjoint_checkbit()) { |
1614 | return; |
1615 | } |
1616 | TI_ASSERT(snode->get_adjoint_checkbit() != nullptr); |
1617 | snode = snode->get_adjoint_checkbit(); |
1618 | auto global_ptr = |
1619 | stmt->insert_after_me(Stmt::make<GlobalPtrStmt>(snode, src->indices)); |
1620 | auto dtype = global_ptr->ret_type; |
1621 | auto one = global_ptr->insert_after_me( |
1622 | Stmt::make<ConstStmt>(TypedConstant(dtype, 1))); |
1623 | one->insert_after_me(Stmt::make<GlobalStoreStmt>(global_ptr, one)); |
1624 | } |
1625 | |
1626 | void visit_gloabl_store_stmt_and_atomic_add(Stmt *stmt, GlobalPtrStmt *dest) { |
1627 | auto snode = dest->snode; |
1628 | if (!snode->has_adjoint_checkbit()) { |
1629 | return; |
1630 | } |
1631 | TI_ASSERT(snode->get_adjoint_checkbit() != nullptr); |
1632 | snode = snode->get_adjoint_checkbit(); |
1633 | auto global_ptr = |
1634 | stmt->insert_before_me(Stmt::make<GlobalPtrStmt>(snode, dest->indices)); |
1635 | auto global_load = |
1636 | stmt->insert_before_me(Stmt::make<GlobalLoadStmt>(global_ptr)); |
1637 | auto dtype = global_ptr->ret_type; |
1638 | auto zero = |
1639 | stmt->insert_before_me(Stmt::make<ConstStmt>(TypedConstant(dtype, 0))); |
1640 | auto check_equal = stmt->insert_before_me( |
1641 | Stmt::make<BinaryOpStmt>(BinaryOpType::cmp_eq, global_load, zero)); |
1642 | std::string msg = fmt::format( |
1643 | "(kernel={}) Breaks the global data access rule. Snode {} is " |
1644 | "overwritten unexpectedly." , |
1645 | kernel_name_, dest->snode->get_node_type_name()); |
1646 | msg += "\n" + stmt->tb; |
1647 | |
1648 | stmt->insert_before_me( |
1649 | Stmt::make<AssertStmt>(check_equal, msg, std::vector<Stmt *>())); |
1650 | } |
1651 | |
1652 | void visit(GlobalStoreStmt *stmt) override { |
1653 | GlobalPtrStmt *dest = stmt->dest->as<GlobalPtrStmt>(); |
1654 | visit_gloabl_store_stmt_and_atomic_add(stmt, dest); |
1655 | } |
1656 | |
1657 | void visit(AtomicOpStmt *stmt) override { |
1658 | GlobalPtrStmt *dest = stmt->dest->as<GlobalPtrStmt>(); |
1659 | visit_gloabl_store_stmt_and_atomic_add(stmt, dest); |
1660 | } |
1661 | |
1662 | static void run(IRNode *root, const std::string &kernel_name) { |
1663 | GloablDataAccessRuleChecker checker; |
1664 | checker.kernel_name_ = kernel_name; |
1665 | root->accept(&checker); |
1666 | } |
1667 | |
1668 | private: |
1669 | std::string kernel_name_; |
1670 | }; |
1671 | |
1672 | void differentiation_validation_check(IRNode *root, |
1673 | const CompileConfig &config, |
1674 | const std::string &kernel_name) { |
1675 | return irpass::GloablDataAccessRuleChecker::run(root, kernel_name); |
1676 | } |
1677 | |
1678 | } // namespace irpass |
1679 | |
1680 | } // namespace taichi::lang |
1681 | |