wbrawner/openssl
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

bn/bn_add.c: address performance regression.

Browse source 
Performance regression was reported for EC key generation between
1.0.2 and 1.1.x [in GH#2891]. It naturally depends on platform,
values between 6 and 9% were observed.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4743)
This commit is contained in:
Andy Polyakov 2017-11-15 12:25:02 +01:00
parent 8e4ec5b2e7
commit a78324d95b
2 changed files with 13 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

14
crypto/bn/asm/x86_64-gcc.c
View file

@ -225,9 +225,10 @@ BN_ULONG bn_add_words(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,
" adcq (%5,%2,8),%0 \n"
" movq %0,(%3,%2,8) \n"
" lea 1(%2),%2 \n"
" loop 1b \n"
" sbbq %0,%0 \n":"=&r" (ret), "+c"(n),
"+r"(i)
" dec %1 \n"
" jnz 1b \n"
" sbbq %0,%0 \n"
:"=&r" (ret), "+c"(n), "+r"(i)
:"r"(rp), "r"(ap), "r"(bp)
:"cc", "memory");
@ -251,9 +252,10 @@ BN_ULONG bn_sub_words(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,
" sbbq (%5,%2,8),%0 \n"
" movq %0,(%3,%2,8) \n"
" lea 1(%2),%2 \n"
" loop 1b \n"
" sbbq %0,%0 \n":"=&r" (ret), "+c"(n),
"+r"(i)
" dec %1 \n"
" jnz 1b \n"
" sbbq %0,%0 \n"
:"=&r" (ret), "+c"(n), "+r"(i)
:"r"(rp), "r"(ap), "r"(bp)
:"cc", "memory");

6
crypto/bn/bn_add.c
View file

@ -141,9 +141,13 @@ int BN_usub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)
borrow &= (t1 == 0);
}
while (max && *--rp == 0)
max--;
r->top = max;
r->neg = 0;
bn_correct_top(r);
bn_pollute(r);
return 1;
}