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static inline void
enc_loop_ssse3_inner (const uint8_t **s, uint8_t **o)
{
// Load input:
__m128i str = _mm_loadu_si128((__m128i *) *s);
// Reshuffle:
str = enc_reshuffle(str);
// Translate reshuffled bytes to the Base64 alphabet:
str = enc_translate(str);
// Store:
_mm_storeu_si128((__m128i *) *o, str);
*s += 12;
*o += 16;
}
static inline void
enc_loop_ssse3 (const uint8_t **s, size_t *slen, uint8_t **o, size_t *olen)
{
if (*slen < 16) {
return;
}
// Process blocks of 12 bytes at a time. Because blocks are loaded 16
// bytes at a time, ensure that there will be at least 4 remaining
// bytes after the last round, so that the final read will not pass
// beyond the bounds of the input buffer:
size_t rounds = (*slen - 4) / 12;
*slen -= rounds * 12; // 12 bytes consumed per round
*olen += rounds * 16; // 16 bytes produced per round
do {
if (rounds >= 8) {
enc_loop_ssse3_inner(s, o);
enc_loop_ssse3_inner(s, o);
enc_loop_ssse3_inner(s, o);
enc_loop_ssse3_inner(s, o);
enc_loop_ssse3_inner(s, o);
enc_loop_ssse3_inner(s, o);
enc_loop_ssse3_inner(s, o);
enc_loop_ssse3_inner(s, o);
rounds -= 8;
continue;
}
if (rounds >= 4) {
enc_loop_ssse3_inner(s, o);
enc_loop_ssse3_inner(s, o);
enc_loop_ssse3_inner(s, o);
enc_loop_ssse3_inner(s, o);
rounds -= 4;
continue;
}
if (rounds >= 2) {
enc_loop_ssse3_inner(s, o);
enc_loop_ssse3_inner(s, o);
rounds -= 2;
continue;
}
enc_loop_ssse3_inner(s, o);
break;
} while (rounds > 0);
}
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