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#if (defined(__ARM_NEON) && !defined(__ARM_NEON__))
#define __ARM_NEON__
#endif
#include <stdint.h>
#include <stddef.h>
#include <stdlib.h>
#ifdef __ARM_NEON__
#include <arm_neon.h>
#endif
#include "libbase64.h"
#include "codecs.h"
#if (defined(__arm__) && defined(__ARM_NEON__))
#define CMPGT(s,n) vcgtq_u8((s), vdupq_n_u8(n))
#define CMPEQ(s,n) vceqq_u8((s), vdupq_n_u8(n))
#define REPLACE(s,n) vandq_u8((s), vdupq_n_u8(n))
#define RANGE(s,a,b) vandq_u8(vcgeq_u8((s), vdupq_n_u8(a)), vcleq_u8((s), vdupq_n_u8(b)))
static inline uint8x16x4_t
enc_reshuffle (uint8x16x3_t in)
{
uint8x16x4_t out;
// Divide bits of three input bytes over four output bytes:
out.val[0] = vshrq_n_u8(in.val[0], 2);
out.val[1] = vorrq_u8(vshrq_n_u8(in.val[1], 4), vshlq_n_u8(in.val[0], 4));
out.val[2] = vorrq_u8(vshrq_n_u8(in.val[2], 6), vshlq_n_u8(in.val[1], 2));
out.val[3] = in.val[2];
// Clear top two bits:
out.val[0] = vandq_u8(out.val[0], vdupq_n_u8(0x3F));
out.val[1] = vandq_u8(out.val[1], vdupq_n_u8(0x3F));
out.val[2] = vandq_u8(out.val[2], vdupq_n_u8(0x3F));
out.val[3] = vandq_u8(out.val[3], vdupq_n_u8(0x3F));
return out;
}
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;
}
#endif
// Stride size is so large on these NEON 32-bit functions
// (48 bytes encode, 32 bytes decode) that we inline the
// uint32 codec to stay performant on smaller inputs.
void
neon32_base64_stream_encode
( struct neon32_base64_state *state
, const char *src
, size_t srclen
, char *out
, size_t *outlen
)
{
#if (defined(__arm__) && defined(__ARM_NEON__))
#include "enc_head.c"
#include "enc_neon.c"
#include "enc_uint32.c"
#include "enc_tail.c"
#else
(void)state;
(void)src;
(void)srclen;
(void)out;
(void)outlen;
abort();
#endif
}
int
neon32_base64_stream_decode
( struct neon32_base64_state *state
, const char *src
, size_t srclen
, char *out
, size_t *outlen
)
{
#if (defined(__arm__) && defined(__ARM_NEON__))
#include "dec_head.c"
#include "dec_neon.c"
#include "dec_uint32.c"
#include "dec_tail.c"
#else
(void)state;
(void)src;
(void)srclen;
(void)out;
(void)outlen;
abort();
#endif
}
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