/* -*-c-*-
*
- * $Id: mp-arith.c,v 1.12 2002/10/09 00:36:03 mdw Exp $
+ * $Id: mp-arith.c,v 1.13 2002/10/15 00:19:40 mdw Exp $
*
* Basic arithmetic on multiprecision integers
*
/*----- Revision history --------------------------------------------------*
*
* $Log: mp-arith.c,v $
+ * Revision 1.13 2002/10/15 00:19:40 mdw
+ * Bit setting and clearing functions.
+ *
* Revision 1.12 2002/10/09 00:36:03 mdw
* Fix bounds on workspace for Karatsuba operations.
*
/* --- @mp_testbit@ --- *
*
* Arguments: @mp *x@ = a large integer
- * @size_t n@ = which bit to test
+ * @unsigned long n@ = which bit to test
*
* Returns: Nonzero if the bit is set, zero if not.
*/
-int mp_testbit(mp *x, size_t n)
+int mp_testbit(mp *x, unsigned long n)
{
- size_t o;
if (n > MPW_BITS * MP_LEN(x))
return (0);
- o = n / MPW_BITS;
- n %= MPW_BITS;
- return ((x->v[o] >> n) & 1);
+ return ((x->v[n/MPW_BITS] >> n%MPW_BITS) & 1u);
}
/* --- @mp_testbit2c@ --- *
*
* Arguments: @mp *x@ = a large integer
- * @size_t n@ = which bit to test
+ * @unsigned long n@ = which bit to test
*
* Returns: Nonzero if the bit is set, zero if not. Fakes up two's
* complement representation.
*/
-int mp_testbit2c(mp *x, size_t n)
+int mp_testbit2c(mp *x, unsigned long n)
{
int r;
- if (x->f & MP_NEG)
+ if (!(x->f & MP_NEG))
return (mp_testbit(x, n));
x = mp_not2c(MP_NEW, x);
r = !mp_testbit(x, n);
return (r);
}
+/* --- @mp_setbit@, @mp_clearbit@ --- *
+ *
+ * Arguments: @mp *d@ = a destination
+ * @mp *x@ = a large integer
+ * @unsigned long n@ = which bit to modify
+ *
+ * Returns: The argument @x@, with the appropriate bit set or cleared.
+ */
+
+mp *mp_setbit(mp *d, mp *x, unsigned long n)
+{
+ size_t rq;
+
+ rq = n + MPW_BITS; rq -= rq % MPW_BITS;
+ if (d != x) {
+ if (d) MP_DROP(d);
+ d = MP_COPY(x);
+ }
+ MP_DEST(d, rq, x->f & (MP_NEG | MP_BURN));
+ d->v[n/MPW_BITS] |= 1 << n%MPW_BITS;
+ return (d);
+}
+
+mp *mp_clearbit(mp *d, mp *x, unsigned long n)
+{
+ size_t rq;
+
+ rq = n + MPW_BITS; rq -= rq % MPW_BITS;
+ if (d != x) {
+ if (d) MP_DROP(d);
+ d = MP_COPY(x);
+ }
+ MP_DEST(d, rq, x->f & (MP_NEG | MP_BURN));
+ d->v[n/MPW_BITS] &= ~(1 << n%MPW_BITS);
+ return (d);
+}
+
+/* --- @mp_setbit2c@, @mp_clearbit2c@ --- *
+ *
+ * Arguments: @mp *d@ = a destination
+ * @mp *x@ = a large integer
+ * @unsigned long n@ = which bit to modify
+ *
+ * Returns: The argument @x@, with the appropriate bit set or cleared.
+ * Fakes up two's complement representation.
+ */
+
+mp *mp_setbit2c(mp *d, mp *x, unsigned long n)
+{
+ if (!(x->f & MP_NEG))
+ return mp_setbit(d, x, n);
+ d = mp_not2c(d, x);
+ d = mp_clearbit(d, d, n);
+ d = mp_not2c(d, d);
+ return (d);
+}
+
+mp *mp_clearbit2c(mp *d, mp *x, unsigned long n)
+{
+ if (!(x->f & MP_NEG))
+ return mp_clearbit(d, x, n);
+ d = mp_not2c(d, x);
+ d = mp_setbit(d, d, n);
+ d = mp_not2c(d, d);
+ return (d);
+}
+
/* --- @mp_eq@ --- *
*
* Arguments: @const mp *a, *b@ = two numbers
return (ok);
}
+static int tset(dstr *v)
+{
+ mp *a = *(mp **)v[0].buf;
+ unsigned long n = *(unsigned long *)v[1].buf;
+ mp *r = *(mp **)v[2].buf;
+ mp *c;
+ int ok = 1;
+
+ c = mp_setbit2c(MP_NEW, a, n);
+ if (!MP_EQ(c, r)) {
+ ok = 0;
+ fprintf(stderr, "\n***setbit (set) failed");
+ fputs("\n*** a = ", stderr); mp_writefile(a, stderr, 16);
+ fprintf(stderr, "\n*** n = %lu", n);
+ fputs("\n*** r = ", stderr); mp_writefile(r, stderr, 16);
+ fputs("\n*** c = ", stderr); mp_writefile(c, stderr, 16);
+ fputc('\n', stderr);
+ }
+ if (!mp_testbit2c(r, n)) {
+ ok = 0;
+ fprintf(stderr, "\n***setbit (test) failed");
+ fprintf(stderr, "\n*** n = %lu", n);
+ fputs("\n*** r = ", stderr); mp_writefile(r, stderr, 16);
+ fputc('\n', stderr);
+ }
+ mp_drop(a);
+ mp_drop(r);
+ mp_drop(c);
+ assert(mparena_count(MPARENA_GLOBAL) == 0);
+ return (ok);
+}
+
+static int tclr(dstr *v)
+{
+ mp *a = *(mp **)v[0].buf;
+ unsigned long n = *(unsigned long *)v[1].buf;
+ mp *r = *(mp **)v[2].buf;
+ mp *c;
+ int ok = 1;
+
+ c = mp_clearbit2c(MP_NEW, a, n);
+ if (!MP_EQ(c, r)) {
+ ok = 0;
+ fprintf(stderr, "\n***clrbit (set) failed");
+ fputs("\n*** a = ", stderr); mp_writefile(a, stderr, 16);
+ fprintf(stderr, "\n*** n = %lu", n);
+ fputs("\n*** r = ", stderr); mp_writefile(r, stderr, 16);
+ fputs("\n*** c = ", stderr); mp_writefile(c, stderr, 16);
+ fputc('\n', stderr);
+ }
+ if (mp_testbit2c(r, n)) {
+ ok = 0;
+ fprintf(stderr, "\n***clrbit (test) failed");
+ fprintf(stderr, "\n*** n = %lu", n);
+ fputs("\n*** r = ", stderr); mp_writefile(r, stderr, 16);
+ fputc('\n', stderr);
+ }
+ mp_drop(a);
+ mp_drop(c);
+ mp_drop(r);
+ assert(mparena_count(MPARENA_GLOBAL) == 0);
+ return (ok);
+}
+
static int todd(dstr *v)
{
mp *a = *(mp **)v[0].buf;
mp_drop(a);
mp_drop(rt);
mp_drop(t);
+ assert(mparena_count(MPARENA_GLOBAL) == 0);
return (ok);
}
{ "lsr", tlsr, { &type_mp, &type_int, &type_mp, 0 } },
{ "lsl2c", tlsl2c, { &type_mp, &type_int, &type_mp, 0 } },
{ "lsr2c", tlsr2c, { &type_mp, &type_int, &type_mp, 0 } },
+ { "setbit", tset, { &type_mp, &type_ulong, &type_mp, 0 } },
+ { "clrbit", tclr, { &type_mp, &type_ulong, &type_mp, 0 } },
{ "add", tadd, { &type_mp, &type_mp, &type_mp, 0 } },
{ "sub", tsub, { &type_mp, &type_mp, &type_mp, 0 } },
{ "mul", tmul, { &type_mp, &type_mp, &type_mp, 0 } },
/* -*-c-*-
*
- * $Id: mp.h,v 1.13 2002/10/06 22:52:50 mdw Exp $
+ * $Id: mp.h,v 1.14 2002/10/15 00:19:40 mdw Exp $
*
* Simple multiprecision arithmetic
*
/*----- Revision history --------------------------------------------------*
*
* $Log: mp.h,v $
+ * Revision 1.14 2002/10/15 00:19:40 mdw
+ * Bit setting and clearing functions.
+ *
* Revision 1.13 2002/10/06 22:52:50 mdw
* Pile of changes for supporting two's complement properly.
*
/* --- @mp_testbit@ --- *
*
* Arguments: @mp *x@ = a large integer
- * @size_t n@ = which bit to test
+ * @unsigned long n@ = which bit to test
*
* Returns: Nonzero if the bit is set, zero if not.
*/
-extern int mp_testbit(mp */*x*/, size_t /*n*/);
+extern int mp_testbit(mp */*x*/, unsigned long /*n*/);
/* --- @mp_testbit2c@ --- *
*
* Arguments: @mp *x@ = a large integer
- * @size_t n@ = which bit to test
+ * @unsigned long n@ = which bit to test
*
* Returns: Nonzero if the bit is set, zero if not. Fakes up two's
* complement representation.
*/
-extern int mp_testbit2c(mp */*x*/, size_t /*n*/);
+extern int mp_testbit2c(mp */*x*/, unsigned long /*n*/);
/* --- @mp_eq@ --- *
*
#define MP_CMP(a, op, b) (mp_cmp((a), (b)) op 0)
+/* --- @mp_setbit@, @mp_clearbit@ --- *
+ *
+ * Arguments: @mp *d@ = a destination
+ * @mp *x@ = a large integer
+ * @unsigned long n@ = which bit to modify
+ *
+ * Returns: The argument @x@, with the appropriate bit set or cleared.
+ */
+
+extern mp *mp_setbit(mp */*d*/, mp */*x*/, unsigned long /*n*/);
+extern mp *mp_clearbit(mp */*d*/, mp */*x*/, unsigned long /*n*/);
+
+/* --- @mp_setbit2c@, @mp_clearbit2c@ --- *
+ *
+ * Arguments: @mp *d@ = a destination
+ * @mp *x@ = a large integer
+ * @unsigned long n@ = which bit to modify
+ *
+ * Returns: The argument @x@, with the appropriate bit set or cleared.
+ * Fakes up two's complement representation.
+ */
+
+extern mp *mp_setbit2c(mp */*d*/, mp */*x*/, unsigned long /*n*/);
+extern mp *mp_clearbit2c(mp */*d*/, mp */*x*/, unsigned long /*n*/);
+
/* --- @mp_bitop@ --- *
*
* Arguments: @mp *d@ = destination