aboutsummaryrefslogtreecommitdiffstats
path: root/crypto/bn/asm/x86_64-gcc.c
diff options
context:
space:
mode:
Diffstat (limited to 'crypto/bn/asm/x86_64-gcc.c')
-rw-r--r--crypto/bn/asm/x86_64-gcc.c34
1 files changed, 15 insertions, 19 deletions
diff --git a/crypto/bn/asm/x86_64-gcc.c b/crypto/bn/asm/x86_64-gcc.c
index 31476abebfb7..2d39407f499e 100644
--- a/crypto/bn/asm/x86_64-gcc.c
+++ b/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