diff options
Diffstat (limited to 'security/nss/lib/freebl/mpi/mpvalpha.c')
| -rw-r--r-- | security/nss/lib/freebl/mpi/mpvalpha.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/security/nss/lib/freebl/mpi/mpvalpha.c b/security/nss/lib/freebl/mpi/mpvalpha.c new file mode 100644 index 0000000000..94e86eedb9 --- /dev/null +++ b/security/nss/lib/freebl/mpi/mpvalpha.c @@ -0,0 +1,183 @@ +/* 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/. */ + +#include "mpi-priv.h" +#include <c_asm.h> + +#define MP_MUL_DxD(a, b, Phi, Plo) \ + { \ + Plo = asm("mulq %a0, %a1, %v0", a, b); \ + Phi = asm("umulh %a0, %a1, %v0", a, b); \ + } + +/* This is empty for the loop in s_mpv_mul_d */ +#define CARRY_ADD + +#define ONE_MUL \ + a_i = *a++; \ + MP_MUL_DxD(a_i, b, a1b1, a0b0); \ + a0b0 += carry; \ + if (a0b0 < carry) \ + ++a1b1; \ + CARRY_ADD \ + *c++ = a0b0; \ + carry = a1b1; + +#define FOUR_MUL \ + ONE_MUL \ + ONE_MUL \ + ONE_MUL \ + ONE_MUL + +#define SIXTEEN_MUL \ + FOUR_MUL \ + FOUR_MUL \ + FOUR_MUL \ + FOUR_MUL + +#define THIRTYTWO_MUL \ + SIXTEEN_MUL \ + SIXTEEN_MUL + +#define ONETWENTYEIGHT_MUL \ + THIRTYTWO_MUL \ + THIRTYTWO_MUL \ + THIRTYTWO_MUL \ + THIRTYTWO_MUL + +#define EXPAND_256(CALL) \ + mp_digit carry = 0; \ + mp_digit a_i; \ + mp_digit a0b0, a1b1; \ + if (a_len & 255) { \ + if (a_len & 1) { \ + ONE_MUL \ + } \ + if (a_len & 2) { \ + ONE_MUL \ + ONE_MUL \ + } \ + if (a_len & 4) { \ + FOUR_MUL \ + } \ + if (a_len & 8) { \ + FOUR_MUL \ + FOUR_MUL \ + } \ + if (a_len & 16) { \ + SIXTEEN_MUL \ + } \ + if (a_len & 32) { \ + THIRTYTWO_MUL \ + } \ + if (a_len & 64) { \ + THIRTYTWO_MUL \ + THIRTYTWO_MUL \ + } \ + if (a_len & 128) { \ + ONETWENTYEIGHT_MUL \ + } \ + a_len = a_len & (-256); \ + } \ + if (a_len >= 256) { \ + carry = CALL(a, a_len, b, c, carry); \ + c += a_len; \ + } + +#define FUNC_NAME(NAME) \ + mp_digit NAME(const mp_digit *a, \ + mp_size a_len, \ + mp_digit b, mp_digit *c, \ + mp_digit carry) + +#define DECLARE_MUL_256(FNAME) \ + FUNC_NAME(FNAME) \ + { \ + mp_digit a_i; \ + mp_digit a0b0, a1b1; \ + while (a_len) { \ + ONETWENTYEIGHT_MUL \ + ONETWENTYEIGHT_MUL \ + a_len -= 256; \ + } \ + return carry; \ + } + +/* Expanding the loop in s_mpv_mul_d appeared to slow down the + (admittedly) small number of tests (i.e., timetest) used to + measure performance, so this define disables that optimization. */ +#define DO_NOT_EXPAND 1 + +/* Need forward declaration so it can be instantiated after + the routine that uses it; this helps locality somewhat */ +#if !defined(DO_NOT_EXPAND) +FUNC_NAME(s_mpv_mul_d_MUL256); +#endif + +/* c = a * b */ +void +s_mpv_mul_d(const mp_digit *a, mp_size a_len, + mp_digit b, mp_digit *c) +{ +#if defined(DO_NOT_EXPAND) + mp_digit carry = 0; + while (a_len--) { + mp_digit a_i = *a++; + mp_digit a0b0, a1b1; + + MP_MUL_DxD(a_i, b, a1b1, a0b0); + + a0b0 += carry; + if (a0b0 < carry) + ++a1b1; + *c++ = a0b0; + carry = a1b1; + } +#else + EXPAND_256(s_mpv_mul_d_MUL256) +#endif + *c = carry; +} + +#if !defined(DO_NOT_EXPAND) +DECLARE_MUL_256(s_mpv_mul_d_MUL256) +#endif + +#undef CARRY_ADD +/* This is redefined for the loop in s_mpv_mul_d_add */ +#define CARRY_ADD \ + a0b0 += a_i = *c; \ + if (a0b0 < a_i) \ + ++a1b1; + +/* Need forward declaration so it can be instantiated between the + two routines that use it; this helps locality somewhat */ +FUNC_NAME(s_mpv_mul_d_add_MUL256); + +/* c += a * b */ +void +s_mpv_mul_d_add(const mp_digit *a, mp_size a_len, + mp_digit b, mp_digit *c) +{ + EXPAND_256(s_mpv_mul_d_add_MUL256) + *c = carry; +} + +/* Instantiate multiply 256 routine here */ +DECLARE_MUL_256(s_mpv_mul_d_add_MUL256) + +/* Presently, this is only used by the Montgomery arithmetic code. */ +/* c += a * b */ +void +s_mpv_mul_d_add_prop(const mp_digit *a, mp_size a_len, + mp_digit b, mp_digit *c) +{ + EXPAND_256(s_mpv_mul_d_add_MUL256) + while (carry) { + mp_digit c_i = *c; + carry += c_i; + *c++ = carry; + carry = carry < c_i; + } +} |