aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/base64/neon64/dec_uint64.c
blob: 90d134af389d4ff29bd0c73938f9823ca322cf1c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
// If we have native uint64's, pick off 8 bytes at a time for as long as we 
// can, but make sure that we quit before seeing any == markers at the end of 
// the string. Also, because we write two zeroes at the end of the output, 
// ensure that there are at least 3 valid bytes of input data remaining to 
// close the gap. 8 + 2 + 3 = 13 bytes: 
while (srclen >= 13) 
{ 
	uint64_t str, res, dec; 
 
	// Load string: 
	str = *(uint64_t *)c; 
 
	// Shuffle bytes to 64-bit bigendian: 
	str = cpu_to_be64(str); 
 
	// Lookup each byte in the decoding table; if we encounter any 
	// "invalid" values, fall back on the bytewise code: 
	if ((dec = neon64_base64_table_dec[str >> 56]) > 63) { 
		break; 
	} 
	res = dec << 58; 
 
	if ((dec = neon64_base64_table_dec[(str >> 48) & 0xFF]) > 63) { 
		break; 
	} 
	res |= dec << 52; 
 
	if ((dec = neon64_base64_table_dec[(str >> 40) & 0xFF]) > 63) { 
		break; 
	} 
	res |= dec << 46; 
 
	if ((dec = neon64_base64_table_dec[(str >> 32) & 0xFF]) > 63) { 
		break; 
	} 
	res |= dec << 40; 
 
	if ((dec = neon64_base64_table_dec[(str >> 24) & 0xFF]) > 63) { 
		break; 
	} 
	res |= dec << 34; 
 
	if ((dec = neon64_base64_table_dec[(str >> 16) & 0xFF]) > 63) { 
		break; 
	} 
	res |= dec << 28; 
 
	if ((dec = neon64_base64_table_dec[(str >> 8) & 0xFF]) > 63) { 
		break; 
	} 
	res |= dec << 22; 
 
	if ((dec = neon64_base64_table_dec[str & 0xFF]) > 63) { 
		break; 
	} 
	res |= dec << 16; 
 
	// Reshuffle and repack into 6-byte output format: 
	res = be64_to_cpu(res); 
 
	// Store back: 
	*(uint64_t *)o = res; 
 
	c += 8; 
	o += 6; 
	outl += 6; 
	srclen -= 8; 
}