+#else
+ {
+ int i, ubits = BN_num_bits(u),
+ vbits = BN_num_bits(v), /* v is copy of p */
+ top = p->top;
+ BN_ULONG *udp,*bdp,*vdp,*cdp;
+
+ bn_wexpand(u,top); udp = u->d;
+ for (i=u->top;i<top;i++) udp[i] = 0;
+ u->top = top;
+ bn_wexpand(b,top); bdp = b->d;
+ bdp[0] = 1;
+ for (i=1;i<top;i++) bdp[i] = 0;
+ b->top = top;
+ bn_wexpand(c,top); cdp = c->d;
+ for (i=0;i<top;i++) cdp[i] = 0;
+ c->top = top;
+ vdp = v->d; /* It pays off to "cache" *->d pointers, because
+ * it allows optimizer to be more aggressive.
+ * But we don't have to "cache" p->d, because *p
+ * is declared 'const'... */
+ while (1)
+ {
+ while (ubits && !(udp[0]&1))
+ {
+ BN_ULONG u0,u1,b0,b1,mask;
+
+ u0 = udp[0];
+ b0 = bdp[0];
+ mask = (BN_ULONG)0-(b0&1);
+ b0 ^= p->d[0]&mask;
+ for (i=0;i<top-1;i++)
+ {
+ u1 = udp[i+1];
+ udp[i] = ((u0>>1)|(u1<<(BN_BITS2-1)))&BN_MASK2;
+ u0 = u1;
+ b1 = bdp[i+1]^(p->d[i+1]&mask);
+ bdp[i] = ((b0>>1)|(b1<<(BN_BITS2-1)))&BN_MASK2;
+ b0 = b1;
+ }
+ udp[i] = u0>>1;
+ bdp[i] = b0>>1;
+ ubits--;
+ }
+
+ if (ubits<=BN_BITS2 && udp[0]==1) break;
+
+ if (ubits<vbits)
+ {
+ i = ubits; ubits = vbits; vbits = i;
+ tmp = u; u = v; v = tmp;
+ tmp = b; b = c; c = tmp;
+ udp = vdp; vdp = v->d;
+ bdp = cdp; cdp = c->d;
+ }
+ for(i=0;i<top;i++)
+ {
+ udp[i] ^= vdp[i];
+ bdp[i] ^= cdp[i];
+ }
+ if (ubits==vbits)
+ {
+ BN_ULONG ul;
+ int utop = (ubits-1)/BN_BITS2;