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-rw-r--r--libtommath/bn_mp_sub_d.c113
1 files changed, 56 insertions, 57 deletions
diff --git a/libtommath/bn_mp_sub_d.c b/libtommath/bn_mp_sub_d.c
index 5e96030..7016abc 100644
--- a/libtommath/bn_mp_sub_d.c
+++ b/libtommath/bn_mp_sub_d.c
@@ -16,74 +16,73 @@
*/
/* single digit subtraction */
-int
-mp_sub_d (mp_int * a, mp_digit b, mp_int * c)
+int mp_sub_d(mp_int *a, mp_digit b, mp_int *c)
{
- mp_digit *tmpa, *tmpc, mu;
- int res, ix, oldused;
+ mp_digit *tmpa, *tmpc, mu;
+ int res, ix, oldused;
- /* grow c as required */
- if (c->alloc < (a->used + 1)) {
- if ((res = mp_grow(c, a->used + 1)) != MP_OKAY) {
- return res;
- }
- }
+ /* grow c as required */
+ if (c->alloc < (a->used + 1)) {
+ if ((res = mp_grow(c, a->used + 1)) != MP_OKAY) {
+ return res;
+ }
+ }
- /* if a is negative just do an unsigned
- * addition [with fudged signs]
- */
- if (a->sign == MP_NEG) {
- a->sign = MP_ZPOS;
- res = mp_add_d(a, b, c);
- a->sign = c->sign = MP_NEG;
+ /* if a is negative just do an unsigned
+ * addition [with fudged signs]
+ */
+ if (a->sign == MP_NEG) {
+ a->sign = MP_ZPOS;
+ res = mp_add_d(a, b, c);
+ a->sign = c->sign = MP_NEG;
- /* clamp */
- mp_clamp(c);
+ /* clamp */
+ mp_clamp(c);
- return res;
- }
+ return res;
+ }
- /* setup regs */
- oldused = c->used;
- tmpa = a->dp;
- tmpc = c->dp;
+ /* setup regs */
+ oldused = c->used;
+ tmpa = a->dp;
+ tmpc = c->dp;
- /* if a <= b simply fix the single digit */
- if (((a->used == 1) && (a->dp[0] <= b)) || (a->used == 0)) {
- if (a->used == 1) {
- *tmpc++ = b - *tmpa;
- } else {
- *tmpc++ = b;
- }
- ix = 1;
+ /* if a <= b simply fix the single digit */
+ if (((a->used == 1) && (a->dp[0] <= b)) || (a->used == 0)) {
+ if (a->used == 1) {
+ *tmpc++ = b - *tmpa;
+ } else {
+ *tmpc++ = b;
+ }
+ ix = 1;
- /* negative/1digit */
- c->sign = MP_NEG;
- c->used = 1;
- } else {
- /* positive/size */
- c->sign = MP_ZPOS;
- c->used = a->used;
+ /* negative/1digit */
+ c->sign = MP_NEG;
+ c->used = 1;
+ } else {
+ /* positive/size */
+ c->sign = MP_ZPOS;
+ c->used = a->used;
- /* subtract first digit */
- *tmpc = *tmpa++ - b;
- mu = *tmpc >> ((sizeof(mp_digit) * CHAR_BIT) - 1);
- *tmpc++ &= MP_MASK;
+ /* subtract first digit */
+ *tmpc = *tmpa++ - b;
+ mu = *tmpc >> ((sizeof(mp_digit) * CHAR_BIT) - 1);
+ *tmpc++ &= MP_MASK;
- /* handle rest of the digits */
- for (ix = 1; ix < a->used; ix++) {
- *tmpc = *tmpa++ - mu;
- mu = *tmpc >> ((sizeof(mp_digit) * CHAR_BIT) - 1);
- *tmpc++ &= MP_MASK;
- }
- }
+ /* handle rest of the digits */
+ for (ix = 1; ix < a->used; ix++) {
+ *tmpc = *tmpa++ - mu;
+ mu = *tmpc >> ((sizeof(mp_digit) * CHAR_BIT) - 1);
+ *tmpc++ &= MP_MASK;
+ }
+ }
- /* zero excess digits */
- while (ix++ < oldused) {
- *tmpc++ = 0;
- }
- mp_clamp(c);
- return MP_OKAY;
+ /* zero excess digits */
+ while (ix++ < oldused) {
+ *tmpc++ = 0;
+ }
+ mp_clamp(c);
+ return MP_OKAY;
}
#endif