| // Copyright 2024 The Dawn & Tint Authors |
| // |
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| #ifndef SRC_TINT_LANG_HLSL_WRITER_RAISE_LOCALIZE_STRUCT_ARRAY_ASSIGNMENT_H_ |
| #define SRC_TINT_LANG_HLSL_WRITER_RAISE_LOCALIZE_STRUCT_ARRAY_ASSIGNMENT_H_ |
| |
| #include "src/tint/utils/result/result.h" |
| |
| // Forward declarations. |
| namespace tint::core::ir { |
| class Module; |
| } // namespace tint::core::ir |
| |
| namespace tint::hlsl::writer::raise { |
| |
| /// This transform replaces assignment to dynamically-indexed fixed-size arrays in structs on |
| /// shader-local variables with code that copies the arrays to a temporary local variable, assigns |
| /// to the local variable, and copies the array back. This is to work around FXC's compilation |
| /// failure for these cases (see crbug.com/tint/1206). |
| /// |
| /// As per Microsoft, this occurs because a structure instance declared in a local variable in FXC |
| /// maps to non-indexable register space. If that contains an array that's dynamically indexed, FXC |
| /// will attempt to resolve indexes to constants. This can force unrolling of loops when indexes are |
| /// loop-dependent. |
| /// |
| /// Our workaround copies the inner array to a local variable, because local array variables are |
| /// mapped to the indexable register space by FXC. |
| |
| /// @param module the module to transform |
| /// @returns success or failure |
| Result<SuccessType> LocalizeStructArrayAssignment(core::ir::Module& module); |
| |
| } // namespace tint::hlsl::writer::raise |
| |
| #endif // SRC_TINT_LANG_HLSL_WRITER_RAISE_LOCALIZE_STRUCT_ARRAY_ASSIGNMENT_H_ |
