X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/45c0fd363937c6e9b05da04a9167e9912c05ca0c..20fa0f6976d598481208c0583d72b2ccef637be9:/gf-gcd.c diff --git a/gf-gcd.c b/gf-gcd.c index 9b5402b..03cee47 100644 --- a/gf-gcd.c +++ b/gf-gcd.c @@ -51,7 +51,7 @@ void gf_gcd(mp **gcd, mp **xx, mp **yy, mp *a, mp *b) mp *x = MP_ONE, *X = MP_ZERO; mp *y = MP_ZERO, *Y = MP_ONE; mp *u, *v; - mp *q = MP_NEW; + mp *q = MP_NEW, *t, *spare = MP_NEW; unsigned f = 0; #define f_swap 1u @@ -69,7 +69,7 @@ void gf_gcd(mp **gcd, mp **xx, mp **yy, mp *a, mp *b) */ if (MPX_UCMP(a->v, a->vl, <, b->v, b->vl)) { - { mp *t = a; a = b; b = t; } + t = a; a = b; b = t; f |= f_swap; } @@ -112,20 +112,19 @@ void gf_gcd(mp **gcd, mp **xx, mp **yy, mp *a, mp *b) v = MP_COPY(b); while (!MP_ZEROP(v)) { - mp *t; gf_div(&q, &u, u, v); if (f & f_ext) { - t = gf_mul(MP_NEW, X, q); + t = gf_mul(spare, X, q); t = gf_add(t, t, x); - MP_DROP(x); x = X; X = t; - t = gf_mul(MP_NEW, Y, q); + spare = x; x = X; X = t; + t = gf_mul(spare, Y, q); t = gf_add(t, t, y); - MP_DROP(y); y = Y; Y = t; + spare = y; y = Y; Y = t; } t = u; u = v; v = t; } - MP_DROP(q); + MP_DROP(q); if (spare) MP_DROP(spare); if (!gcd) MP_DROP(u); else { @@ -141,7 +140,7 @@ void gf_gcd(mp **gcd, mp **xx, mp **yy, mp *a, mp *b) /* --- If @a@ and @b@ got swapped, swap the coefficients back --- */ if (f & f_swap) { - mp *t = x; x = y; y = t; + t = x; x = y; y = t; t = a; a = b; b = t; }