simdjson/src/arm64/stringparsing.h

#ifndef SIMDJSON_ARM64_STRINGPARSING_H
#define SIMDJSON_ARM64_STRINGPARSING_H

#include "simdjson/portability.h"

#ifdef IS_ARM64

#include "simdjson/common_defs.h"
#include "simdjson/parsedjson.h"
#include "jsoncharutils.h"

#ifdef JSON_TEST_STRINGS
void found_string(const uint8_t *buf, const uint8_t *parsed_begin,
                  const uint8_t *parsed_end);
void found_bad_string(const uint8_t *buf);
#endif

namespace simdjson::arm64 {

// Holds backslashes and quotes locations.
struct parse_string_helper {
  uint32_t bs_bits;
  uint32_t quote_bits;
  really_inline uint32_t bytes_processed() const { return sizeof(uint8x16_t)*2; }
};

really_inline parse_string_helper find_bs_bits_and_quote_bits(const uint8_t *src, uint8_t *dst) {
  // this can read up to 31 bytes beyond the buffer size, but we require
  // SIMDJSON_PADDING of padding
  static_assert(2 * sizeof(uint8x16_t) - 1 <= SIMDJSON_PADDING);
  uint8x16_t v0 = vld1q_u8(src);
  uint8x16_t v1 = vld1q_u8(src + 16);
  vst1q_u8(dst, v0);
  vst1q_u8(dst + 16, v1);

  uint8x16_t bs_mask = vmovq_n_u8('\\');
  uint8x16_t qt_mask = vmovq_n_u8('"');
  const uint8x16_t bit_mask = {0x01, 0x02, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80,
                               0x01, 0x02, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80};
  uint8x16_t cmp_bs_0 = vceqq_u8(v0, bs_mask);
  uint8x16_t cmp_bs_1 = vceqq_u8(v1, bs_mask);
  uint8x16_t cmp_qt_0 = vceqq_u8(v0, qt_mask);
  uint8x16_t cmp_qt_1 = vceqq_u8(v1, qt_mask);

  cmp_bs_0 = vandq_u8(cmp_bs_0, bit_mask);
  cmp_bs_1 = vandq_u8(cmp_bs_1, bit_mask);
  cmp_qt_0 = vandq_u8(cmp_qt_0, bit_mask);
  cmp_qt_1 = vandq_u8(cmp_qt_1, bit_mask);

  uint8x16_t sum0 = vpaddq_u8(cmp_bs_0, cmp_bs_1);
  uint8x16_t sum1 = vpaddq_u8(cmp_qt_0, cmp_qt_1);
  sum0 = vpaddq_u8(sum0, sum1);
  sum0 = vpaddq_u8(sum0, sum0);
  return {
      vgetq_lane_u32(vreinterpretq_u32_u8(sum0), 0), // bs_bits
      vgetq_lane_u32(vreinterpretq_u32_u8(sum0), 1)  // quote_bits
  };

}

#include "generic/stringparsing.h"

}
// namespace simdjson::amd64

#endif // IS_ARM64
#endif