| // Copyright 2021 The Dawn & Tint Authors |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are met: |
| // |
| // 1. Redistributions of source code must retain the above copyright notice, this |
| // list of conditions and the following disclaimer. |
| // |
| // 2. Redistributions in binary form must reproduce the above copyright notice, |
| // this list of conditions and the following disclaimer in the documentation |
| // and/or other materials provided with the distribution. |
| // |
| // 3. Neither the name of the copyright holder nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE |
| // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
| // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #ifndef SRC_TINT_LANG_MSL_WRITER_AST_RAISE_MODULE_SCOPE_VAR_TO_ENTRY_POINT_PARAM_H_ |
| #define SRC_TINT_LANG_MSL_WRITER_AST_RAISE_MODULE_SCOPE_VAR_TO_ENTRY_POINT_PARAM_H_ |
| |
| #include "src/tint/lang/wgsl/ast/transform/transform.h" |
| |
| namespace tint::msl::writer { |
| |
| /// Move module-scope variables into the entry point as parameters. |
| /// |
| /// MSL does not allow module-scope variables to have any address space other |
| /// than `constant`. This transform moves all module-scope declarations into the |
| /// entry point function (either as parameters or function-scope variables) and |
| /// then passes them as pointer parameters to any function that references them. |
| /// |
| /// Since WGSL does not allow entry point parameters or function-scope variables |
| /// to have these address spaces, we annotate the new variable declarations |
| /// with an attribute that bypasses that validation rule. |
| /// |
| /// Before: |
| /// ``` |
| /// struct S { |
| /// f : f32; |
| /// }; |
| /// @binding(0) @group(0) |
| /// var<storage, read> s : S; |
| /// var<private> p : f32 = 2.0; |
| /// |
| /// fn foo() { |
| /// p = p + f; |
| /// } |
| /// |
| /// @compute @workgroup_size(1) |
| /// fn main() { |
| /// foo(); |
| /// } |
| /// ``` |
| /// |
| /// After: |
| /// ``` |
| /// fn foo(p : ptr<private, f32>, sptr : ptr<storage, S, read>) { |
| /// *p = *p + (*sptr).f; |
| /// } |
| /// |
| /// @compute @workgroup_size(1) |
| /// fn main(sptr : ptr<storage, S, read>) { |
| /// var<private> p : f32 = 2.0; |
| /// foo(&p, sptr); |
| /// } |
| /// ``` |
| class ModuleScopeVarToEntryPointParam final |
| : public Castable<ModuleScopeVarToEntryPointParam, ast::transform::Transform> { |
| public: |
| /// Constructor |
| ModuleScopeVarToEntryPointParam(); |
| /// Destructor |
| ~ModuleScopeVarToEntryPointParam() override; |
| |
| /// @copydoc ast::transform::Transform::Apply |
| ApplyResult Apply(const Program& program, |
| const ast::transform::DataMap& inputs, |
| ast::transform::DataMap& outputs) const override; |
| |
| private: |
| struct State; |
| }; |
| |
| } // namespace tint::msl::writer |
| |
| #endif // SRC_TINT_LANG_MSL_WRITER_AST_RAISE_MODULE_SCOPE_VAR_TO_ENTRY_POINT_PARAM_H_ |