diff options
Diffstat (limited to 'openssl/crypto/bn/asm/x86_64-gcc.c')
| -rw-r--r-- | openssl/crypto/bn/asm/x86_64-gcc.c | 34 |
1 files changed, 15 insertions, 19 deletions
diff --git a/openssl/crypto/bn/asm/x86_64-gcc.c b/openssl/crypto/bn/asm/x86_64-gcc.c index 31476abeb..2d39407f4 100644 --- a/openssl/crypto/bn/asm/x86_64-gcc.c +++ b/openssl/crypto/bn/asm/x86_64-gcc.c @@ -273,6 +273,10 @@ BN_ULONG bn_sub_words(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n) /* sqr_add_c(a,i,c0,c1,c2) -- c+=a[i]^2 for three word number c=(c2,c1,c0) */ /* sqr_add_c2(a,i,c0,c1,c2) -- c+=2*a[i]*a[j] for three word number c=(c2,c1,c0) */ +/* + * Keep in mind that carrying into high part of multiplication result + * can not overflow, because it cannot be all-ones. + */ #if 0 /* original macros are kept for reference purposes */ #define mul_add_c(a,b,c0,c1,c2) { \ @@ -287,10 +291,10 @@ BN_ULONG bn_sub_words(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n) BN_ULONG ta=(a),tb=(b),t0; \ t1 = BN_UMULT_HIGH(ta,tb); \ t0 = ta * tb; \ - t2 = t1+t1; c2 += (t2<t1)?1:0; \ - t1 = t0+t0; t2 += (t1<t0)?1:0; \ - c0 += t1; t2 += (c0<t1)?1:0; \ + c0 += t0; t2 = t1+((c0<t0)?1:0);\ c1 += t2; c2 += (c1<t2)?1:0; \ + c0 += t0; t1 += (c0<t0)?1:0; \ + c1 += t1; c2 += (c1<t1)?1:0; \ } #else #define mul_add_c(a,b,c0,c1,c2) do { \ @@ -328,22 +332,14 @@ BN_ULONG bn_sub_words(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n) : "=a"(t1),"=d"(t2) \ : "a"(a),"m"(b) \ : "cc"); \ - asm ("addq %0,%0; adcq %2,%1" \ - : "+d"(t2),"+r"(c2) \ - : "g"(0) \ - : "cc"); \ - asm ("addq %0,%0; adcq %2,%1" \ - : "+a"(t1),"+d"(t2) \ - : "g"(0) \ - : "cc"); \ - asm ("addq %2,%0; adcq %3,%1" \ - : "+r"(c0),"+d"(t2) \ - : "a"(t1),"g"(0) \ - : "cc"); \ - asm ("addq %2,%0; adcq %3,%1" \ - : "+r"(c1),"+r"(c2) \ - : "d"(t2),"g"(0) \ - : "cc"); \ + asm ("addq %3,%0; adcq %4,%1; adcq %5,%2" \ + : "+r"(c0),"+r"(c1),"+r"(c2) \ + : "r"(t1),"r"(t2),"g"(0) \ + : "cc"); \ + asm ("addq %3,%0; adcq %4,%1; adcq %5,%2" \ + : "+r"(c0),"+r"(c1),"+r"(c2) \ + : "r"(t1),"r"(t2),"g"(0) \ + : "cc"); \ } while (0) #endif |