src/utils/numeric.h

// Copyright 2025 The Dawn & Tint Authors
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#ifndef SRC_UTILS_NUMERIC_H_
#define SRC_UTILS_NUMERIC_H_

#include <limits>
#include <type_traits>

namespace dawn {
template <typename T>
bool inline IsDoubleValueRepresentable(double value) {
    if constexpr (std::is_same_v<T, float> || std::is_integral_v<T>) {
        // Following WebIDL 3.3.6.[EnforceRange] for integral
        // Following WebIDL 3.2.5.float for float
        // TODO(crbug.com/1396194): now follows what blink does but may need revisit.
        constexpr double kLowest = static_cast<double>(std::numeric_limits<T>::lowest());
        constexpr double kMax = static_cast<double>(std::numeric_limits<T>::max());
        return kLowest <= value && value <= kMax;
    } else {
        static_assert(std::is_same_v<T, float> || std::is_integral_v<T>, "Unsupported type");
    }
}

inline bool IsDoubleValueRepresentableAsF16(double value) {
    constexpr double kLowestF16 = -65504.0;
    constexpr double kMaxF16 = 65504.0;
    return kLowestF16 <= value && value <= kMaxF16;
}
}  // namespace dawn

#endif  // SRC_UTILS_NUMERIC_H_