// Load string:
__m128i str = _mm_loadu_si128((__m128i *)c);
// The input consists of six character sets in the Base64 alphabet,
// which we need to map back to the 6-bit values they represent.
// There are three ranges, two singles, and then there's the rest.
//
// # From To Add Characters
// 1 [43] [62] +19 +
// 2 [47] [63] +16 /
// 3 [48..57] [52..61] +4 0..9
// 4 [65..90] [0..25] -65 A..Z
// 5 [97..122] [26..51] -71 a..z
// (6) Everything else => invalid input
const __m128i set1 = CMPEQ(str, '+');
const __m128i set2 = CMPEQ(str, '/');
const __m128i set3 = RANGE(str, '0', '9');
const __m128i set4 = RANGE(str, 'A', 'Z');
const __m128i set5 = RANGE(str, 'a', 'z');
__m128i delta = REPLACE(set1, 19);
delta = _mm_or_si128(delta, REPLACE(set2, 16));
delta = _mm_or_si128(delta, REPLACE(set3, 4));
delta = _mm_or_si128(delta, REPLACE(set4, -65));
delta = _mm_or_si128(delta, REPLACE(set5, -71));
// Check for invalid input: if any of the delta values are zero,
// fall back on bytewise code to do error checking and reporting:
if (_mm_movemask_epi8(CMPEQ(delta, 0))) {
break;
// Load string:
__m256i str = _mm256_loadu_si256((__m256i *)c);
// The input consists of six character sets in the Base64 alphabet,
// which we need to map back to the 6-bit values they represent.
// There are three ranges, two singles, and then there's the rest.
//
// # From To Add Characters
// 1 [43] [62] +19 +
// 2 [47] [63] +16 /
// 3 [48..57] [52..61] +4 0..9
// 4 [65..90] [0..25] -65 A..Z
// 5 [97..122] [26..51] -71 a..z
// (6) Everything else => invalid input
const __m256i set1 = CMPEQ(str, '+');
const __m256i set2 = CMPEQ(str, '/');
const __m256i set3 = RANGE(str, '0', '9');
const __m256i set4 = RANGE(str, 'A', 'Z');
const __m256i set5 = RANGE(str, 'a', 'z');
__m256i delta = REPLACE(set1, 19);
delta = _mm256_or_si256(delta, REPLACE(set2, 16));
delta = _mm256_or_si256(delta, REPLACE(set3, 4));
delta = _mm256_or_si256(delta, REPLACE(set4, -65));
delta = _mm256_or_si256(delta, REPLACE(set5, -71));
// Check for invalid input: if any of the delta values are zero,
// fall back on bytewise code to do error checking and reporting:
if (_mm256_movemask_epi8(CMPEQ(delta, 0))) {
break;
static inline uint8x16x4_t
enc_translate (uint8x16x4_t in)
{
uint8x16x4_t mask1, mask2, mask3, mask4, out;
// Translate values 0..63 to the Base64 alphabet. There are five sets:
// # From To Abs Delta Characters
// 0 [0..25] [65..90] +65 +65 ABCDEFGHIJKLMNOPQRSTUVWXYZ
// 1 [26..51] [97..122] +71 +6 abcdefghijklmnopqrstuvwxyz
// 2 [52..61] [48..57] -4 -75 0123456789
// 3 [62] [43] -19 -15 +
// 4 [63] [47] -16 +3 /
// Create cumulative masks for characters in sets [1,2,3,4], [2,3,4],
// [3,4], and [4]:
mask1.val[0] = CMPGT(in.val[0], 25);
mask1.val[1] = CMPGT(in.val[1], 25);
mask1.val[2] = CMPGT(in.val[2], 25);
mask1.val[3] = CMPGT(in.val[3], 25);
mask2.val[0] = CMPGT(in.val[0], 51);
mask2.val[1] = CMPGT(in.val[1], 51);
mask2.val[2] = CMPGT(in.val[2], 51);
mask2.val[3] = CMPGT(in.val[3], 51);
mask3.val[0] = CMPGT(in.val[0], 61);
mask3.val[1] = CMPGT(in.val[1], 61);
mask3.val[2] = CMPGT(in.val[2], 61);
mask3.val[3] = CMPGT(in.val[3], 61);
mask4.val[0] = CMPEQ(in.val[0], 63);
mask4.val[1] = CMPEQ(in.val[1], 63);
mask4.val[2] = CMPEQ(in.val[2], 63);
mask4.val[3] = CMPEQ(in.val[3], 63);
// All characters are at least in cumulative set 0, so add 'A':
out.val[0] = vaddq_u8(in.val[0], vdupq_n_u8(65));
out.val[1] = vaddq_u8(in.val[1], vdupq_n_u8(65));
out.val[2] = vaddq_u8(in.val[2], vdupq_n_u8(65));
out.val[3] = vaddq_u8(in.val[3], vdupq_n_u8(65));
// For inputs which are also in any of the other cumulative sets,
// add delta values against the previous set(s) to correct the shift:
out.val[0] = vaddq_u8(out.val[0], REPLACE(mask1.val[0], 6));
out.val[1] = vaddq_u8(out.val[1], REPLACE(mask1.val[1], 6));
out.val[2] = vaddq_u8(out.val[2], REPLACE(mask1.val[2], 6));
out.val[3] = vaddq_u8(out.val[3], REPLACE(mask1.val[3], 6));
out.val[0] = vsubq_u8(out.val[0], REPLACE(mask2.val[0], 75));
out.val[1] = vsubq_u8(out.val[1], REPLACE(mask2.val[1], 75));
out.val[2] = vsubq_u8(out.val[2], REPLACE(mask2.val[2], 75));
out.val[3] = vsubq_u8(out.val[3], REPLACE(mask2.val[3], 75));
out.val[0] = vsubq_u8(out.val[0], REPLACE(mask3.val[0], 15));
out.val[1] = vsubq_u8(out.val[1], REPLACE(mask3.val[1], 15));
out.val[2] = vsubq_u8(out.val[2], REPLACE(mask3.val[2], 15));
out.val[3] = vsubq_u8(out.val[3], REPLACE(mask3.val[3], 15));
out.val[0] = vaddq_u8(out.val[0], REPLACE(mask4.val[0], 3));
out.val[1] = vaddq_u8(out.val[1], REPLACE(mask4.val[1], 3));
out.val[2] = vaddq_u8(out.val[2], REPLACE(mask4.val[2], 3));
out.val[3] = vaddq_u8(out.val[3], REPLACE(mask4.val[3], 3));
return out;
}
