eqemu-server/libs/zlibng/arch/arm/adler32_neon.c
2019-06-30 18:13:46 -07:00

135 lines
4.4 KiB
C

/* Copyright (C) 1995-2011, 2016 Mark Adler
* Copyright (C) 2017 ARM Holdings Inc.
* Author: Adenilson Cavalcanti <adenilson.cavalcanti@arm.com>
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*/
#include "adler32_neon.h"
#if defined(__ARM_NEON__) || defined(__ARM_NEON)
#include <arm_neon.h>
#include "adler32_p.h"
static void NEON_accum32(uint32_t *s, const unsigned char *buf, size_t len) {
static const uint8_t taps[32] = {
32, 31, 30, 29, 28, 27, 26, 25,
24, 23, 22, 21, 20, 19, 18, 17,
16, 15, 14, 13, 12, 11, 10, 9,
8, 7, 6, 5, 4, 3, 2, 1 };
uint32x2_t adacc2, s2acc2, as;
uint8x16_t t0 = vld1q_u8(taps), t1 = vld1q_u8(taps + 16);
uint32x4_t adacc = vdupq_n_u32(0), s2acc = vdupq_n_u32(0);
adacc = vsetq_lane_u32(s[0], adacc, 0);
s2acc = vsetq_lane_u32(s[1], s2acc, 0);
while (len >= 2) {
uint8x16_t d0 = vld1q_u8(buf), d1 = vld1q_u8(buf + 16);
uint16x8_t adler, sum2;
s2acc = vaddq_u32(s2acc, vshlq_n_u32(adacc, 5));
adler = vpaddlq_u8( d0);
adler = vpadalq_u8(adler, d1);
sum2 = vmull_u8( vget_low_u8(t0), vget_low_u8(d0));
sum2 = vmlal_u8(sum2, vget_high_u8(t0), vget_high_u8(d0));
sum2 = vmlal_u8(sum2, vget_low_u8(t1), vget_low_u8(d1));
sum2 = vmlal_u8(sum2, vget_high_u8(t1), vget_high_u8(d1));
adacc = vpadalq_u16(adacc, adler);
s2acc = vpadalq_u16(s2acc, sum2);
len -= 2;
buf += 32;
}
while (len > 0) {
uint8x16_t d0 = vld1q_u8(buf);
uint16x8_t adler, sum2;
s2acc = vaddq_u32(s2acc, vshlq_n_u32(adacc, 4));
adler = vpaddlq_u8(d0);
sum2 = vmull_u8( vget_low_u8(t1), vget_low_u8(d0));
sum2 = vmlal_u8(sum2, vget_high_u8(t1), vget_high_u8(d0));
adacc = vpadalq_u16(adacc, adler);
s2acc = vpadalq_u16(s2acc, sum2);
buf += 16;
len--;
}
adacc2 = vpadd_u32(vget_low_u32(adacc), vget_high_u32(adacc));
s2acc2 = vpadd_u32(vget_low_u32(s2acc), vget_high_u32(s2acc));
as = vpadd_u32(adacc2, s2acc2);
s[0] = vget_lane_u32(as, 0);
s[1] = vget_lane_u32(as, 1);
}
static void NEON_handle_tail(uint32_t *pair, const unsigned char *buf, size_t len) {
unsigned int i;
for (i = 0; i < len; ++i) {
pair[0] += buf[i];
pair[1] += pair[0];
}
}
uint32_t adler32_neon(uint32_t adler, const unsigned char *buf, size_t len) {
/* split Adler-32 into component sums */
uint32_t sum2 = (adler >> 16) & 0xffff;
adler &= 0xffff;
/* in case user likes doing a byte at a time, keep it fast */
if (len == 1)
return adler32_len_1(adler, buf, sum2);
/* initial Adler-32 value (deferred check for len == 1 speed) */
if (buf == NULL)
return 1L;
/* in case short lengths are provided, keep it somewhat fast */
if (len < 16)
return adler32_len_16(adler, buf, len, sum2);
uint32_t pair[2];
int n = NMAX;
unsigned int done = 0;
unsigned int i;
/* Split Adler-32 into component sums, it can be supplied by
* the caller sites (e.g. in a PNG file).
*/
pair[0] = adler;
pair[1] = sum2;
for (i = 0; i < len; i += n) {
if ((i + n) > len)
n = len - i;
if (n < 16)
break;
NEON_accum32(pair, buf + i, n / 16);
pair[0] %= BASE;
pair[1] %= BASE;
done += (n / 16) * 16;
}
/* Handle the tail elements. */
if (done < len) {
NEON_handle_tail(pair, (buf + done), len - done);
pair[0] %= BASE;
pair[1] %= BASE;
}
/* D = B * 65536 + A, see: https://en.wikipedia.org/wiki/Adler-32. */
return (pair[1] << 16) | pair[0];
}
#endif