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1 | | -//===--- SILBitField.h - Defines the bitfield utilities ---------*- C++ -*-===// |
| 1 | +//===--- BasicBlockBits.h - SILBasicBlock bit utilities ---------*- C++ -*-===// |
2 | 2 | // |
3 | 3 | // This source file is part of the Swift.org open source project |
4 | 4 | // |
|
10 | 10 | // |
11 | 11 | //===----------------------------------------------------------------------===// |
12 | 12 | // |
13 | | -// This file defines the BasicBlockBitfield and BasicBlockFlag utilities. |
| 13 | +// This file defines utilities for BasicBlock bit fields and sets. |
14 | 14 | // |
15 | 15 | //===----------------------------------------------------------------------===// |
16 | 16 |
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@@ -211,6 +211,63 @@ template <unsigned N> class BasicBlockSetVector { |
211 | 211 | } |
212 | 212 | }; |
213 | 213 |
|
| 214 | +/// A utility for processing basic blocks in a worklist. |
| 215 | +/// |
| 216 | +/// It is basically a combination of a block vector and a block set. It can be |
| 217 | +/// used for typical worklist-processing algorithms. |
| 218 | +template <unsigned N> class BasicBlockWorklist { |
| 219 | + llvm::SmallVector<SILBasicBlock *, N> worklist; |
| 220 | + BasicBlockSet visited; |
| 221 | + |
| 222 | +public: |
| 223 | + /// Construct an empty worklist. |
| 224 | + BasicBlockWorklist(SILFunction *function) : visited(function) {} |
| 225 | + |
| 226 | + /// Initialize the worklist with \p initialBlock. |
| 227 | + BasicBlockWorklist(SILBasicBlock *initialBlock) |
| 228 | + : visited(initialBlock->getParent()) { |
| 229 | + push(initialBlock); |
| 230 | + } |
| 231 | + |
| 232 | + /// Pops the last added element from the worklist or returns null, if the |
| 233 | + /// worklist is empty. |
| 234 | + SILBasicBlock *pop() { |
| 235 | + if (worklist.empty()) |
| 236 | + return nullptr; |
| 237 | + return worklist.pop_back_val(); |
| 238 | + } |
| 239 | + |
| 240 | + /// Pushes \p block onto the worklist if \p block has never been push before. |
| 241 | + bool pushIfNotVisited(SILBasicBlock *block) { |
| 242 | + if (visited.insert(block)) { |
| 243 | + worklist.push_back(block); |
| 244 | + return true; |
| 245 | + } |
| 246 | + return false; |
| 247 | + } |
| 248 | + |
| 249 | + /// Like `pushIfNotVisited`, but requires that \p block has never been on the |
| 250 | + /// worklist before. |
| 251 | + void push(SILBasicBlock *block) { |
| 252 | + assert(!visited.contains(block)); |
| 253 | + visited.insert(block); |
| 254 | + worklist.push_back(block); |
| 255 | + } |
| 256 | + |
| 257 | + /// Like `pop`, but marks the returned block as "unvisited". This means, that |
| 258 | + /// the block can be pushed onto the worklist again. |
| 259 | + SILBasicBlock *popAndForget() { |
| 260 | + if (worklist.empty()) |
| 261 | + return nullptr; |
| 262 | + SILBasicBlock *block = worklist.pop_back_val(); |
| 263 | + visited.erase(block); |
| 264 | + return block; |
| 265 | + } |
| 266 | + |
| 267 | + /// Returns true if \p block was visited, i.e. has been added to the worklist. |
| 268 | + bool isVisited(SILBasicBlock *block) const { return visited.contains(block); } |
| 269 | +}; |
| 270 | + |
214 | 271 | } // namespace swift |
215 | 272 |
|
216 | 273 | #endif |
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