| // Copyright (c) 2017 Google Inc. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #ifndef LIBSPIRV_UTIL_FOLD_H_ |
| #define LIBSPIRV_UTIL_FOLD_H_ |
| |
| #include <cstdint> |
| #include <vector> |
| |
| #include "const_folding_rules.h" |
| #include "constants.h" |
| #include "def_use_manager.h" |
| |
| namespace spvtools { |
| namespace opt { |
| |
| // Returns a reference to the ConstnatFoldingRules instance. |
| const ConstantFoldingRules& GetConstantFoldingRules(); |
| |
| // Returns the result of folding a scalar instruction with the given |opcode| |
| // and |operands|. Each entry in |operands| is a pointer to an |
| // analysis::Constant instance, which should've been created with the constant |
| // manager (See IRContext::get_constant_mgr). |
| // |
| // It is an error to call this function with an opcode that does not pass the |
| // IsFoldableOpcode test. If any error occurs during folding, the folder will |
| // faill with a call to assert. |
| uint32_t FoldScalars(SpvOp opcode, |
| const std::vector<const analysis::Constant*>& operands); |
| |
| // Returns the result of performing an operation with the given |opcode| over |
| // constant vectors with |num_dims| dimensions. Each entry in |operands| is a |
| // pointer to an analysis::Constant instance, which should've been created with |
| // the constant manager (See IRContext::get_constant_mgr). |
| // |
| // This function iterates through the given vector type constant operands and |
| // calculates the result for each element of the result vector to return. |
| // Vectors with longer than 32-bit scalar components are not accepted in this |
| // function. |
| // |
| // It is an error to call this function with an opcode that does not pass the |
| // IsFoldableOpcode test. If any error occurs during folding, the folder will |
| // faill with a call to assert. |
| std::vector<uint32_t> FoldVectors( |
| SpvOp opcode, uint32_t num_dims, |
| const std::vector<const analysis::Constant*>& operands); |
| |
| // Returns true if |opcode| represents an operation handled by FoldScalars or |
| // FoldVectors. |
| bool IsFoldableOpcode(SpvOp opcode); |
| |
| // Returns true if |cst| is supported by FoldScalars and FoldVectors. |
| bool IsFoldableConstant(const analysis::Constant* cst); |
| |
| // Returns true if |FoldInstructionToConstant| could fold an instruction whose |
| // result type is |type_inst|. |
| bool IsFoldableType(ir::Instruction* type_inst); |
| |
| // Tries to fold |inst| to a single constant, when the input ids to |inst| have |
| // been substituted using |id_map|. Returns a pointer to the OpConstant* |
| // instruction if successful. If necessary, a new constant instruction is |
| // created and placed in the global values section. |
| // |
| // |id_map| is a function that takes one result id and returns another. It can |
| // be used for things like CCP where it is known that some ids contain a |
| // constant, but the instruction itself has not been updated yet. This can map |
| // those ids to the appropriate constants. |
| ir::Instruction* FoldInstructionToConstant( |
| ir::Instruction* inst, std::function<uint32_t(uint32_t)> id_map); |
| |
| // Returns true if |inst| can be folded into a simpler instruction. |
| // If |inst| can be simplified, |inst| is overwritten with the simplified |
| // instruction reusing the same result id. |
| // |
| // If |inst| is simplified, it is possible that the resulting code in invalid |
| // because the instruction is in a bad location. Callers of this function have |
| // to handle the following cases: |
| // |
| // 1) An OpPhi becomes and OpCopyObject - If there are OpPhi instruction after |
| // |inst| in a basic block then this is invalid. The caller must fix this |
| // up. |
| bool FoldInstruction(ir::Instruction* inst); |
| |
| } // namespace opt |
| } // namespace spvtools |
| |
| #endif // LIBSPIRV_UTIL_FOLD_H_ |