MLIR  16.0.0git
Serializer.h
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1 //===- Serializer.h - MLIR SPIR-V Serializer ------------------------------===//
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 // This file declares the MLIR SPIR-V module to SPIR-V binary serializer.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef MLIR_LIB_TARGET_SPIRV_SERIALIZATION_SERIALIZER_H
14 #define MLIR_LIB_TARGET_SPIRV_SERIALIZATION_SERIALIZER_H
15 
17 #include "mlir/IR/Builders.h"
19 #include "llvm/ADT/SetVector.h"
20 #include "llvm/ADT/SmallVector.h"
21 #include "llvm/Support/raw_ostream.h"
22 
23 namespace mlir {
24 namespace spirv {
25 
26 void encodeInstructionInto(SmallVectorImpl<uint32_t> &binary, spirv::Opcode op,
27  ArrayRef<uint32_t> operands);
28 
29 /// A SPIR-V module serializer.
30 ///
31 /// A SPIR-V binary module is a single linear stream of instructions; each
32 /// instruction is composed of 32-bit words with the layout:
33 ///
34 /// | <word-count>|<opcode> | <operand> | <operand> | ... |
35 /// | <------ word -------> | <-- word --> | <-- word --> | ... |
36 ///
37 /// For the first word, the 16 high-order bits are the word count of the
38 /// instruction, the 16 low-order bits are the opcode enumerant. The
39 /// instructions then belong to different sections, which must be laid out in
40 /// the particular order as specified in "2.4 Logical Layout of a Module" of
41 /// the SPIR-V spec.
42 class Serializer {
43 public:
44  /// Creates a serializer for the given SPIR-V `module`.
45  explicit Serializer(spirv::ModuleOp module,
46  const SerializationOptions &options);
47 
48  /// Serializes the remembered SPIR-V module.
50 
51  /// Collects the final SPIR-V `binary`.
52  void collect(SmallVectorImpl<uint32_t> &binary);
53 
54 #ifndef NDEBUG
55  /// (For debugging) prints each value and its corresponding result <id>.
56  void printValueIDMap(raw_ostream &os);
57 #endif
58 
59 private:
60  // Note that there are two main categories of methods in this class:
61  // * process*() methods are meant to fully serialize a SPIR-V module entity
62  // (header, type, op, etc.). They update internal vectors containing
63  // different binary sections. They are not meant to be called except the
64  // top-level serialization loop.
65  // * prepare*() methods are meant to be helpers that prepare for serializing
66  // certain entity. They may or may not update internal vectors containing
67  // different binary sections. They are meant to be called among themselves
68  // or by other process*() methods for subtasks.
69 
70  //===--------------------------------------------------------------------===//
71  // <id>
72  //===--------------------------------------------------------------------===//
73 
74  // Note that it is illegal to use id <0> in SPIR-V binary module. Various
75  // methods in this class, if using SPIR-V word (uint32_t) as interface,
76  // check or return id <0> to indicate error in processing.
77 
78  /// Consumes the next unused <id>. This method will never return 0.
79  uint32_t getNextID() { return nextID++; }
80 
81  //===--------------------------------------------------------------------===//
82  // Module structure
83  //===--------------------------------------------------------------------===//
84 
85  uint32_t getSpecConstID(StringRef constName) const {
86  return specConstIDMap.lookup(constName);
87  }
88 
89  uint32_t getVariableID(StringRef varName) const {
90  return globalVarIDMap.lookup(varName);
91  }
92 
93  uint32_t getFunctionID(StringRef fnName) const {
94  return funcIDMap.lookup(fnName);
95  }
96 
97  /// Gets the <id> for the function with the given name. Assigns the next
98  /// available <id> if the function haven't been deserialized.
99  uint32_t getOrCreateFunctionID(StringRef fnName);
100 
101  void processCapability();
102 
103  void processDebugInfo();
104 
105  void processExtension();
106 
107  void processMemoryModel();
108 
109  LogicalResult processConstantOp(spirv::ConstantOp op);
110 
111  LogicalResult processSpecConstantOp(spirv::SpecConstantOp op);
112 
114  processSpecConstantCompositeOp(spirv::SpecConstantCompositeOp op);
115 
117  processSpecConstantOperationOp(spirv::SpecConstantOperationOp op);
118 
119  /// SPIR-V dialect supports OpUndef using spirv.UndefOp that produces a SSA
120  /// value to use with other operations. The SPIR-V spec recommends that
121  /// OpUndef be generated at module level. The serialization generates an
122  /// OpUndef for each type needed at module level.
123  LogicalResult processUndefOp(spirv::UndefOp op);
124 
125  /// Emit OpName for the given `resultID`.
126  LogicalResult processName(uint32_t resultID, StringRef name);
127 
128  /// Processes a SPIR-V function op.
129  LogicalResult processFuncOp(spirv::FuncOp op);
130 
131  LogicalResult processVariableOp(spirv::VariableOp op);
132 
133  /// Process a SPIR-V GlobalVariableOp
134  LogicalResult processGlobalVariableOp(spirv::GlobalVariableOp varOp);
135 
136  /// Process attributes that translate to decorations on the result <id>
137  LogicalResult processDecoration(Location loc, uint32_t resultID,
138  NamedAttribute attr);
139 
140  template <typename DType>
141  LogicalResult processTypeDecoration(Location loc, DType type,
142  uint32_t resultId) {
143  return emitError(loc, "unhandled decoration for type:") << type;
144  }
145 
146  /// Process member decoration
147  LogicalResult processMemberDecoration(
148  uint32_t structID,
149  const spirv::StructType::MemberDecorationInfo &memberDecorationInfo);
150 
151  //===--------------------------------------------------------------------===//
152  // Types
153  //===--------------------------------------------------------------------===//
154 
155  uint32_t getTypeID(Type type) const { return typeIDMap.lookup(type); }
156 
157  Type getVoidType() { return mlirBuilder.getNoneType(); }
158 
159  bool isVoidType(Type type) const { return type.isa<NoneType>(); }
160 
161  /// Returns true if the given type is a pointer type to a struct in some
162  /// interface storage class.
163  bool isInterfaceStructPtrType(Type type) const;
164 
165  /// Main dispatch method for serializing a type. The result <id> of the
166  /// serialized type will be returned as `typeID`.
167  LogicalResult processType(Location loc, Type type, uint32_t &typeID);
168  LogicalResult processTypeImpl(Location loc, Type type, uint32_t &typeID,
169  SetVector<StringRef> &serializationCtx);
170 
171  /// Method for preparing basic SPIR-V type serialization. Returns the type's
172  /// opcode and operands for the instruction via `typeEnum` and `operands`.
173  LogicalResult prepareBasicType(Location loc, Type type, uint32_t resultID,
174  spirv::Opcode &typeEnum,
175  SmallVectorImpl<uint32_t> &operands,
176  bool &deferSerialization,
177  SetVector<StringRef> &serializationCtx);
178 
179  LogicalResult prepareFunctionType(Location loc, FunctionType type,
180  spirv::Opcode &typeEnum,
181  SmallVectorImpl<uint32_t> &operands);
182 
183  //===--------------------------------------------------------------------===//
184  // Constant
185  //===--------------------------------------------------------------------===//
186 
187  uint32_t getConstantID(Attribute value) const {
188  return constIDMap.lookup(value);
189  }
190 
191  /// Main dispatch method for processing a constant with the given `constType`
192  /// and `valueAttr`. `constType` is needed here because we can interpret the
193  /// `valueAttr` as a different type than the type of `valueAttr` itself; for
194  /// example, ArrayAttr, whose type is NoneType, is used for spirv::ArrayType
195  /// constants.
196  uint32_t prepareConstant(Location loc, Type constType, Attribute valueAttr);
197 
198  /// Prepares array attribute serialization. This method emits corresponding
199  /// OpConstant* and returns the result <id> associated with it. Returns 0 if
200  /// failed.
201  uint32_t prepareArrayConstant(Location loc, Type constType, ArrayAttr attr);
202 
203  /// Prepares bool/int/float DenseElementsAttr serialization. This method
204  /// iterates the DenseElementsAttr to construct the constant array, and
205  /// returns the result <id> associated with it. Returns 0 if failed. Note
206  /// that the size of `index` must match the rank.
207  /// TODO: Consider to enhance splat elements cases. For splat cases,
208  /// we don't need to loop over all elements, especially when the splat value
209  /// is zero. We can use OpConstantNull when the value is zero.
210  uint32_t prepareDenseElementsConstant(Location loc, Type constType,
211  DenseElementsAttr valueAttr, int dim,
213 
214  /// Prepares scalar attribute serialization. This method emits corresponding
215  /// OpConstant* and returns the result <id> associated with it. Returns 0 if
216  /// the attribute is not for a scalar bool/integer/float value. If `isSpec` is
217  /// true, then the constant will be serialized as a specialization constant.
218  uint32_t prepareConstantScalar(Location loc, Attribute valueAttr,
219  bool isSpec = false);
220 
221  uint32_t prepareConstantBool(Location loc, BoolAttr boolAttr,
222  bool isSpec = false);
223 
224  uint32_t prepareConstantInt(Location loc, IntegerAttr intAttr,
225  bool isSpec = false);
226 
227  uint32_t prepareConstantFp(Location loc, FloatAttr floatAttr,
228  bool isSpec = false);
229 
230  //===--------------------------------------------------------------------===//
231  // Control flow
232  //===--------------------------------------------------------------------===//
233 
234  /// Returns the result <id> for the given block.
235  uint32_t getBlockID(Block *block) const { return blockIDMap.lookup(block); }
236 
237  /// Returns the result <id> for the given block. If no <id> has been assigned,
238  /// assigns the next available <id>
239  uint32_t getOrCreateBlockID(Block *block);
240 
241 #ifndef NDEBUG
242  /// (For debugging) prints the block with its result <id>.
243  void printBlock(Block *block, raw_ostream &os);
244 #endif
245 
246  /// Processes the given `block` and emits SPIR-V instructions for all ops
247  /// inside. Does not emit OpLabel for this block if `omitLabel` is true.
248  /// `emitMerge` is a callback that will be invoked before handling the
249  /// terminator op to inject the Op*Merge instruction if this is a SPIR-V
250  /// selection/loop header block.
251  LogicalResult processBlock(Block *block, bool omitLabel = false,
252  function_ref<LogicalResult()> emitMerge = nullptr);
253 
254  /// Emits OpPhi instructions for the given block if it has block arguments.
255  LogicalResult emitPhiForBlockArguments(Block *block);
256 
257  LogicalResult processSelectionOp(spirv::SelectionOp selectionOp);
258 
259  LogicalResult processLoopOp(spirv::LoopOp loopOp);
260 
261  LogicalResult processBranchConditionalOp(spirv::BranchConditionalOp);
262 
263  LogicalResult processBranchOp(spirv::BranchOp branchOp);
264 
265  //===--------------------------------------------------------------------===//
266  // Operations
267  //===--------------------------------------------------------------------===//
268 
269  LogicalResult encodeExtensionInstruction(Operation *op,
270  StringRef extensionSetName,
271  uint32_t opcode,
272  ArrayRef<uint32_t> operands);
273 
274  uint32_t getValueID(Value val) const { return valueIDMap.lookup(val); }
275 
276  LogicalResult processAddressOfOp(spirv::AddressOfOp addressOfOp);
277 
278  LogicalResult processReferenceOfOp(spirv::ReferenceOfOp referenceOfOp);
279 
280  /// Main dispatch method for serializing an operation.
281  LogicalResult processOperation(Operation *op);
282 
283  /// Serializes an operation `op` as core instruction with `opcode` if
284  /// `extInstSet` is empty. Otherwise serializes it as an extended instruction
285  /// with `opcode` from `extInstSet`.
286  /// This method is a generic one for dispatching any SPIR-V ops that has no
287  /// variadic operands and attributes in TableGen definitions.
288  LogicalResult processOpWithoutGrammarAttr(Operation *op, StringRef extInstSet,
289  uint32_t opcode);
290 
291  /// Dispatches to the serialization function for an operation in SPIR-V
292  /// dialect that is a mirror of an instruction in the SPIR-V spec. This is
293  /// auto-generated from ODS. Dispatch is handled for all operations in SPIR-V
294  /// dialect that have hasOpcode == 1.
295  LogicalResult dispatchToAutogenSerialization(Operation *op);
296 
297  /// Serializes an operation in the SPIR-V dialect that is a mirror of an
298  /// instruction in the SPIR-V spec. This is auto generated if hasOpcode == 1
299  /// and autogenSerialization == 1 in ODS.
300  template <typename OpTy>
301  LogicalResult processOp(OpTy op) {
302  return op.emitError("unsupported op serialization");
303  }
304 
305  //===--------------------------------------------------------------------===//
306  // Utilities
307  //===--------------------------------------------------------------------===//
308 
309  /// Emits an OpDecorate instruction to decorate the given `target` with the
310  /// given `decoration`.
311  LogicalResult emitDecoration(uint32_t target, spirv::Decoration decoration,
312  ArrayRef<uint32_t> params = {});
313 
314  /// Emits an OpLine instruction with the given `loc` location information into
315  /// the given `binary` vector.
316  LogicalResult emitDebugLine(SmallVectorImpl<uint32_t> &binary, Location loc);
317 
318 private:
319  /// The SPIR-V module to be serialized.
320  spirv::ModuleOp module;
321 
322  /// An MLIR builder for getting MLIR constructs.
323  mlir::Builder mlirBuilder;
324 
325  /// Serialization options.
326  SerializationOptions options;
327 
328  /// A flag which indicates if the last processed instruction was a merge
329  /// instruction.
330  /// According to SPIR-V spec: "If a branch merge instruction is used, the last
331  /// OpLine in the block must be before its merge instruction".
332  bool lastProcessedWasMergeInst = false;
333 
334  /// The <id> of the OpString instruction, which specifies a file name, for
335  /// use by other debug instructions.
336  uint32_t fileID = 0;
337 
338  /// The next available result <id>.
339  uint32_t nextID = 1;
340 
341  // The following are for different SPIR-V instruction sections. They follow
342  // the logical layout of a SPIR-V module.
343 
344  SmallVector<uint32_t, 4> capabilities;
345  SmallVector<uint32_t, 0> extensions;
346  SmallVector<uint32_t, 0> extendedSets;
347  SmallVector<uint32_t, 3> memoryModel;
348  SmallVector<uint32_t, 0> entryPoints;
349  SmallVector<uint32_t, 4> executionModes;
352  SmallVector<uint32_t, 0> decorations;
353  SmallVector<uint32_t, 0> typesGlobalValues;
354  SmallVector<uint32_t, 0> functions;
355 
356  /// Recursive struct references are serialized as OpTypePointer instructions
357  /// to the recursive struct type. However, the OpTypePointer instruction
358  /// cannot be emitted before the recursive struct's OpTypeStruct.
359  /// RecursiveStructPointerInfo stores the data needed to emit such
360  /// OpTypePointer instructions after forward references to such types.
361  struct RecursiveStructPointerInfo {
362  uint32_t pointerTypeID;
363  spirv::StorageClass storageClass;
364  };
365 
366  // Maps spirv::StructType to its recursive reference member info.
368  recursiveStructInfos;
369 
370  /// `functionHeader` contains all the instructions that must be in the first
371  /// block in the function, and `functionBody` contains the rest. After
372  /// processing FuncOp, the encoded instructions of a function are appended to
373  /// `functions`. An example of instructions in `functionHeader` in order:
374  /// OpFunction ...
375  /// OpFunctionParameter ...
376  /// OpFunctionParameter ...
377  /// OpLabel ...
378  /// OpVariable ...
379  /// OpVariable ...
380  SmallVector<uint32_t, 0> functionHeader;
381  SmallVector<uint32_t, 0> functionBody;
382 
383  /// Map from type used in SPIR-V module to their <id>s.
384  DenseMap<Type, uint32_t> typeIDMap;
385 
386  /// Map from constant values to their <id>s.
388 
389  /// Map from specialization constant names to their <id>s.
390  llvm::StringMap<uint32_t> specConstIDMap;
391 
392  /// Map from GlobalVariableOps name to <id>s.
393  llvm::StringMap<uint32_t> globalVarIDMap;
394 
395  /// Map from FuncOps name to <id>s.
396  llvm::StringMap<uint32_t> funcIDMap;
397 
398  /// Map from blocks to their <id>s.
399  DenseMap<Block *, uint32_t> blockIDMap;
400 
401  /// Map from the Type to the <id> that represents undef value of that type.
402  DenseMap<Type, uint32_t> undefValIDMap;
403 
404  /// Map from results of normal operations to their <id>s.
405  DenseMap<Value, uint32_t> valueIDMap;
406 
407  /// Map from extended instruction set name to <id>s.
408  llvm::StringMap<uint32_t> extendedInstSetIDMap;
409 
410  /// Map from values used in OpPhi instructions to their offset in the
411  /// `functions` section.
412  ///
413  /// When processing a block with arguments, we need to emit OpPhi
414  /// instructions to record the predecessor block <id>s and the values they
415  /// send to the block in question. But it's not guaranteed all values are
416  /// visited and thus assigned result <id>s. So we need this list to capture
417  /// the offsets into `functions` where a value is used so that we can fix it
418  /// up later after processing all the blocks in a function.
419  ///
420  /// More concretely, say if we are visiting the following blocks:
421  ///
422  /// ```mlir
423  /// ^phi(%arg0: i32):
424  /// ...
425  /// ^parent1:
426  /// ...
427  /// spirv.Branch ^phi(%val0: i32)
428  /// ^parent2:
429  /// ...
430  /// spirv.Branch ^phi(%val1: i32)
431  /// ```
432  ///
433  /// When we are serializing the `^phi` block, we need to emit at the beginning
434  /// of the block OpPhi instructions which has the following parameters:
435  ///
436  /// OpPhi id-for-i32 id-for-%arg0 id-for-%val0 id-for-^parent1
437  /// id-for-%val1 id-for-^parent2
438  ///
439  /// But we don't know the <id> for %val0 and %val1 yet. One way is to visit
440  /// all the blocks twice and use the first visit to assign an <id> to each
441  /// value. But it's paying the overheads just for OpPhi emission. Instead,
442  /// we still visit the blocks once for emission. When we emit the OpPhi
443  /// instructions, we use 0 as a placeholder for the <id>s for %val0 and %val1.
444  /// At the same time, we record their offsets in the emitted binary (which is
445  /// placed inside `functions`) here. And then after emitting all blocks, we
446  /// replace the dummy <id> 0 with the real result <id> by overwriting
447  /// `functions[offset]`.
448  DenseMap<Value, SmallVector<size_t, 1>> deferredPhiValues;
449 };
450 } // namespace spirv
451 } // namespace mlir
452 
453 #endif // MLIR_LIB_TARGET_SPIRV_SERIALIZATION_SERIALIZER_H
Include the generated interface declarations.
Operation is a basic unit of execution within MLIR.
Definition: Operation.h:28
Block represents an ordered list of Operations.
Definition: Block.h:29
Serializer(spirv::ModuleOp module, const SerializationOptions &options)
Creates a serializer for the given SPIR-V module.
Definition: Serializer.cpp:84
NoneType getNoneType()
Definition: Builders.cpp:81
void encodeInstructionInto(SmallVectorImpl< uint32_t > &binary, spirv::Opcode op, ArrayRef< uint32_t > operands)
Encodes an SPIR-V instruction with the given opcode and operands into the given binary vector...
Definition: Serializer.cpp:77
static constexpr const bool value
void collect(SmallVectorImpl< uint32_t > &binary)
Collects the final SPIR-V binary.
Definition: Serializer.cpp:112
This class defines the main interface for locations in MLIR and acts as a non-nullable wrapper around...
Definition: Location.h:48
NamedAttribute represents a combination of a name and an Attribute value.
Definition: Attributes.h:150
void printValueIDMap(raw_ostream &os)
(For debugging) prints each value and its corresponding result <id>.
Definition: Serializer.cpp:138
This class represents an efficient way to signal success or failure.
Definition: LogicalResult.h:26
An attribute that represents a reference to a dense vector or tensor object.
A SPIR-V module serializer.
Definition: Serializer.h:42
Attributes are known-constant values of operations.
Definition: Attributes.h:25
Special case of IntegerAttr to represent boolean integers, i.e., signless i1 integers.
Instances of the Type class are uniqued, have an immutable identifier and an optional mutable compone...
Definition: Types.h:74
This class represents an instance of an SSA value in the MLIR system, representing a computable value...
Definition: Value.h:85
InFlightDiagnostic emitError(Location loc)
Utility method to emit an error message using this location.
This class is a general helper class for creating context-global objects like types, attributes, and affine expressions.
Definition: Builders.h:49
LogicalResult serialize()
Serializes the remembered SPIR-V module.
Definition: Serializer.cpp:88
bool isa() const
Definition: Types.h:258