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#ifndef SIMDUTF_VALID_UTF32_TO_UTF16_H
#define SIMDUTF_VALID_UTF32_TO_UTF16_H
namespace simdutf {
namespace scalar {
namespace {
namespace utf32_to_utf16 {
template <endianness big_endian>
inline size_t convert_valid(const char32_t *buf, size_t len,
char16_t *utf16_output) {
const uint32_t *data = reinterpret_cast<const uint32_t *>(buf);
size_t pos = 0;
char16_t *start{utf16_output};
while (pos < len) {
uint32_t word = data[pos];
if ((word & 0xFFFF0000) == 0) {
// will not generate a surrogate pair
*utf16_output++ = !match_system(big_endian)
? char16_t(utf16::swap_bytes(uint16_t(word)))
: char16_t(word);
pos++;
} else {
// will generate a surrogate pair
word -= 0x10000;
uint16_t high_surrogate = uint16_t(0xD800 + (word >> 10));
uint16_t low_surrogate = uint16_t(0xDC00 + (word & 0x3FF));
if (!match_system(big_endian)) {
high_surrogate = utf16::swap_bytes(high_surrogate);
low_surrogate = utf16::swap_bytes(low_surrogate);
}
*utf16_output++ = char16_t(high_surrogate);
*utf16_output++ = char16_t(low_surrogate);
pos++;
}
}
return utf16_output - start;
}
} // namespace utf32_to_utf16
} // unnamed namespace
} // namespace scalar
} // namespace simdutf
#endif
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