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#include "node_simd.h"
#include <string_view>
#if NODE_HAS_SIMD_NEON
#include <arm_neon.h>
#endif
namespace node {
namespace simd {
#if NODE_HAS_SIMD_NEON
uint32_t utf8_byte_length(const uint8_t* data, size_t length) {
uint64_t result{0};
const int lanes = sizeof(uint8x16_t);
const int max_sra_count = 256 / lanes; // Avoid overflowing vaddvq_u8.
const int unrolls = max_sra_count;
const int unrolled_lanes = lanes * unrolls;
const uint8_t* unroll_end = data + (length / unrolled_lanes) * unrolled_lanes;
uint32_t length_after_unroll = length % unrolled_lanes;
for (; data < unroll_end;) {
uint8x16_t acc = {};
for (int i = 0; i < unrolls; ++i, data += lanes) {
uint8x16_t chunk = vld1q_u8(data);
acc = vsraq_n_u8(acc, chunk, 7);
}
result += vaddvq_u8(acc);
}
const uint8_t* simd_end = data + (length_after_unroll / lanes) * lanes;
uint32_t length_after_simd = length % lanes;
uint8x16_t acc = {};
for (; data < simd_end; data += lanes) {
uint8x16_t chunk = vld1q_u8(data);
acc = vsraq_n_u8(acc, chunk, 7);
}
result += vaddvq_u8(acc);
const uint8_t* scalar_end = data + length_after_simd;
for (; data < scalar_end; data += 1) {
result += *data >> 7;
}
return result + length;
}
#else
uint32_t utf8_byte_length(const uint8_t* data, size_t length) {
uint32_t result = 0;
for (uint32_t i = 0; i < length; ++i) {
result += (data[i] >> 7);
}
result += length;
return result;
}
#endif
} // namespace simd
} // namespace node
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