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#ifndef SRC_TINT_LANG_WGSL_AST_TRANSFORM_DEMOTE_TO_HELPER_H_
#define SRC_TINT_LANG_WGSL_AST_TRANSFORM_DEMOTE_TO_HELPER_H_

#include "src/tint/lang/wgsl/ast/transform/transform.h"

namespace tint::ast::transform {

/// Implement demote-to-helper semantics for discard statements.
///
/// For backend targets that implement discard by terminating the invocation, we need to change the
/// program to ensure that discarding the fragment does not affect uniformity with respect to
/// derivative operations. We do this by setting a global flag and masking all writes to storage
/// buffers and textures.
///
/// @note Depends on the following transforms to have been run first:
/// * PromoteSideEffectsToDecl
/// * ExpandCompoundAssignment
class DemoteToHelper final : public Castable<DemoteToHelper, Transform> {
  public:
    /// Constructor
    DemoteToHelper();
    /// Destructor
    ~DemoteToHelper() override;

    /// @copydoc Transform::Apply
    ApplyResult Apply(const Program& program,
                      const DataMap& inputs,
                      DataMap& outputs) const override;
};

}  // namespace tint::ast::transform

#endif  // SRC_TINT_LANG_WGSL_AST_TRANSFORM_DEMOTE_TO_HELPER_H_