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tls: P256: x86-64 assembly

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function                                             old     new   delta
sp_256_mont_mul_8                                    127     155     +28
sp_256_proj_point_dbl_8                              448     469     +21
sp_256_mont_sub_8                                     23      35     +12
sp_256_mont_dbl_8                                     26      38     +12
sp_256_sub_8                                          44      49      +5
sp_256_ecc_mulmod_8                                 1530    1535      +5
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 6/0 up/down: 83/0)               Total: 83 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2021-10-06 17:17:34 +02:00
parent 22fd8fd3f4
commit 911344a998
1 changed files with 99 additions and 0 deletions
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99
networking/tls_sp_c32.c
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@ -189,6 +189,34 @@ static int sp_256_add_8(sp_digit* r, const sp_digit* a, const sp_digit* b)
"\n movl %3, 7*4(%2)"
"\n"
"\n sbbl %3, %3"
"\n"
: "=r" (a), "=r" (b), "=r" (r), "=r" (reg)
: "0" (a), "1" (b), "2" (r)
: "memory"
);
return reg;
#elif ALLOW_ASM && defined(__GNUC__) && defined(__x86_64__)
/* x86_64 has no alignment restrictions, and is little-endian,
* so 64-bit and 32-bit representations are identical */
uint64_t reg;
asm volatile (
"\n movq (%0), %3"
"\n addq (%1), %3"
"\n movq %3, (%2)"
"\n"
"\n movq 1*8(%0), %3"
"\n adcq 1*8(%1), %3"
"\n movq %3, 1*8(%2)"
"\n"
"\n movq 2*8(%0), %3"
"\n adcq 2*8(%1), %3"
"\n movq %3, 2*8(%2)"
"\n"
"\n movq 3*8(%0), %3"
"\n adcq 3*8(%1), %3"
"\n movq %3, 3*8(%2)"
"\n"
"\n sbbq %3, %3"
"\n"
: "=r" (a), "=r" (b), "=r" (r), "=r" (reg)
: "0" (a), "1" (b), "2" (r)
@ -259,6 +287,34 @@ static int sp_256_sub_8(sp_digit* r, const sp_digit* a, const sp_digit* b)
"\n movl %3, 7*4(%2)"
"\n"
"\n sbbl %3, %3"
"\n"
: "=r" (a), "=r" (b), "=r" (r), "=r" (reg)
: "0" (a), "1" (b), "2" (r)
: "memory"
);
return reg;
#elif ALLOW_ASM && defined(__GNUC__) && defined(__x86_64__)
/* x86_64 has no alignment restrictions, and is little-endian,
* so 64-bit and 32-bit representations are identical */
uint64_t reg;
asm volatile (
"\n movq (%0), %3"
"\n subq (%1), %3"
"\n movq %3, (%2)"
"\n"
"\n movq 1*8(%0), %3"
"\n sbbq 1*8(%1), %3"
"\n movq %3, 1*8(%2)"
"\n"
"\n movq 2*8(%0), %3"
"\n sbbq 2*8(%1), %3"
"\n movq %3, 2*8(%2)"
"\n"
"\n movq 3*8(%0), %3"
"\n sbbq 3*8(%1), %3"
"\n movq %3, 3*8(%2)"
"\n"
"\n sbbq %3, %3"
"\n"
: "=r" (a), "=r" (b), "=r" (r), "=r" (reg)
: "0" (a), "1" (b), "2" (r)
@ -380,6 +436,49 @@ static void sp_256_mul_8(sp_digit* r, const sp_digit* a, const sp_digit* b)
}
r[15] = accl;
memcpy(r, rr, sizeof(rr));
#elif ALLOW_ASM && defined(__GNUC__) && defined(__x86_64__)
/* x86_64 has no alignment restrictions, and is little-endian,
* so 64-bit and 32-bit representations are identical */
const uint64_t* aa = (const void*)a;
const uint64_t* bb = (const void*)b;
uint64_t rr[8];
int k;
uint64_t accl;
uint64_t acch;
acch = accl = 0;
for (k = 0; k < 7; k++) {
int i, j;
uint64_t acc_hi;
i = k - 3;
if (i < 0)
i = 0;
j = k - i;
acc_hi = 0;
do {
////////////////////////
// uint128_t m = ((uint128_t)a[i]) * b[j];
// acc_hi:acch:accl += m;
asm volatile (
// aa[i] is already loaded in %%rax
"\n mulq %7"
"\n addq %%rax, %0"
"\n adcq %%rdx, %1"
"\n adcq $0, %2"
: "=rm" (accl), "=rm" (acch), "=rm" (acc_hi)
: "0" (accl), "1" (acch), "2" (acc_hi), "a" (aa[i]), "m" (bb[j])
: "cc", "dx"
);
////////////////////////
j--;
i++;
} while (i != 4 && i <= k);
rr[k] = accl;
accl = acch;
acch = acc_hi;
}
rr[7] = accl;
memcpy(r, rr, sizeof(rr));
#elif 0
//TODO: arm assembly (untested)
sp_digit tmp[16];