RetroZilla/security/nss/lib/freebl/mpi/mpi_hp.c
2018-05-19 22:01:21 +08:00

83 lines
2.4 KiB
C

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* This file contains routines that perform vector multiplication. */
#include "mpi-priv.h"
#include <unistd.h>
#include <stddef.h>
/* #include <sys/systeminfo.h> */
#include <strings.h>
extern void multacc512(
int length, /* doublewords in multiplicand vector. */
const mp_digit *scalaraddr, /* Address of scalar. */
const mp_digit *multiplicand, /* The multiplicand vector. */
mp_digit * result); /* Where to accumulate the result. */
extern void maxpy_little(
int length, /* doublewords in multiplicand vector. */
const mp_digit *scalaraddr, /* Address of scalar. */
const mp_digit *multiplicand, /* The multiplicand vector. */
mp_digit * result); /* Where to accumulate the result. */
extern void add_diag_little(
int length, /* doublewords in input vector. */
const mp_digit *root, /* The vector to square. */
mp_digit * result); /* Where to accumulate the result. */
void
s_mpv_sqr_add_prop(const mp_digit *pa, mp_size a_len, mp_digit *ps)
{
add_diag_little(a_len, pa, ps);
}
#define MAX_STACK_DIGITS 258
#define MULTACC512_LEN (512 / MP_DIGIT_BIT)
#define HP_MPY_ADD_FN (a_len == MULTACC512_LEN ? multacc512 : maxpy_little)
/* c = a * b */
void
s_mpv_mul_d(const mp_digit *a, mp_size a_len, mp_digit b, mp_digit *c)
{
mp_digit x[MAX_STACK_DIGITS];
mp_digit *px = x;
size_t xSize = 0;
if (a == c) {
if (a_len > MAX_STACK_DIGITS) {
xSize = sizeof(mp_digit) * (a_len + 2);
px = malloc(xSize);
if (!px)
return;
}
memcpy(px, a, a_len * sizeof(*a));
a = px;
}
s_mp_setz(c, a_len + 1);
HP_MPY_ADD_FN(a_len, &b, a, c);
if (px != x && px) {
memset(px, 0, xSize);
free(px);
}
}
/* c += a * b, where a is a_len words long. */
void
s_mpv_mul_d_add(const mp_digit *a, mp_size a_len, mp_digit b, mp_digit *c)
{
c[a_len] = 0; /* so carry propagation stops here. */
HP_MPY_ADD_FN(a_len, &b, a, c);
}
/* c += a * b, where a is y words long. */
void
s_mpv_mul_d_add_prop(const mp_digit *a, mp_size a_len, mp_digit b,
mp_digit *c)
{
HP_MPY_ADD_FN(a_len, &b, a, c);
}