/* -*-c-*-
*
- * $Id: mpx.c,v 1.11 2001/04/03 19:36:05 mdw Exp $
+ * $Id: mpx.c,v 1.12 2002/10/06 22:52:50 mdw Exp $
*
* Low-level multiprecision arithmetic
*
/*----- Revision history --------------------------------------------------*
*
* $Log: mpx.c,v $
+ * Revision 1.12 2002/10/06 22:52:50 mdw
+ * Pile of changes for supporting two's complement properly.
+ *
* Revision 1.11 2001/04/03 19:36:05 mdw
* Add some simple bitwise operations so that Perl can use them.
*
MPX_ZERO(v, vl);
}
+/* --- @mpx_storel2cn@ --- *
+ *
+ * Arguments: @const mpw *v, *vl@ = base and limit of source vector
+ * @void *pp@ = pointer to octet array
+ * @size_t sz@ = size of octet array
+ *
+ * Returns: ---
+ *
+ * Use: Stores a negative MP in an octet array, least significant
+ * octet first, as two's complement. High-end octets are
+ * silently discarded if there isn't enough space for them.
+ * This obviously makes the output bad.
+ */
+
+void mpx_storel2cn(const mpw *v, const mpw *vl, void *pp, size_t sz)
+{
+ unsigned c = 1;
+ unsigned b = 0;
+ mpw n, w = 0;
+ octet *p = pp, *q = p + sz;
+ unsigned bits = 0;
+
+ while (p < q) {
+ if (bits < 8) {
+ if (v >= vl) {
+ b = w;
+ break;
+ }
+ n = *v++;
+ b = w | n << bits;
+ w = n >> (8 - bits);
+ bits += MPW_BITS - 8;
+ } else {
+ b = w;
+ w >>= 8;
+ bits -= 8;
+ }
+ b = U8(~b + c);
+ c = !b;
+ *p++ = b;
+ }
+ while (p < q) {
+ b = U8(~b + c);
+ c = !b;
+ *p++ = b;
+ b = 0;
+ }
+}
+
+/* --- @mpx_loadl2cn@ --- *
+ *
+ * Arguments: @mpw *v, *vl@ = base and limit of destination vector
+ * @const void *pp@ = pointer to octet array
+ * @size_t sz@ = size of octet array
+ *
+ * Returns: ---
+ *
+ * Use: Loads a negative MP in an octet array, least significant
+ * octet first, as two's complement. High-end octets are
+ * ignored if there isn't enough space for them. This probably
+ * means you made the wrong choice coming here.
+ */
+
+void mpx_loadl2cn(mpw *v, mpw *vl, const void *pp, size_t sz)
+{
+ unsigned n;
+ unsigned c = 1;
+ mpw w = 0;
+ const octet *p = pp, *q = p + sz;
+ unsigned bits = 0;
+
+ if (v >= vl)
+ return;
+ while (p < q) {
+ n = U8(~(*p++) + c);
+ c = !n;
+ w |= n << bits;
+ bits += 8;
+ if (bits >= MPW_BITS) {
+ *v++ = MPW(w);
+ w = n >> (MPW_BITS - bits + 8);
+ bits -= MPW_BITS;
+ if (v >= vl)
+ return;
+ }
+ }
+ *v++ = w;
+ MPX_ZERO(v, vl);
+}
+
+/* --- @mpx_storeb2cn@ --- *
+ *
+ * Arguments: @const mpw *v, *vl@ = base and limit of source vector
+ * @void *pp@ = pointer to octet array
+ * @size_t sz@ = size of octet array
+ *
+ * Returns: ---
+ *
+ * Use: Stores a negative MP in an octet array, most significant
+ * octet first, as two's complement. High-end octets are
+ * silently discarded if there isn't enough space for them,
+ * which probably isn't what you meant.
+ */
+
+void mpx_storeb2cn(const mpw *v, const mpw *vl, void *pp, size_t sz)
+{
+ mpw n, w = 0;
+ unsigned b = 0;
+ unsigned c = 1;
+ octet *p = pp, *q = p + sz;
+ unsigned bits = 0;
+
+ while (q > p) {
+ if (bits < 8) {
+ if (v >= vl) {
+ b = w;
+ break;
+ }
+ n = *v++;
+ b = w | n << bits;
+ w = n >> (8 - bits);
+ bits += MPW_BITS - 8;
+ } else {
+ b = w;
+ w >>= 8;
+ bits -= 8;
+ }
+ b = U8(~b + c);
+ c = !b;
+ *--q = b;
+ }
+ while (q > p) {
+ b = ~b + c;
+ c = !(b & 0xff);
+ *--q = b;
+ b = 0;
+ }
+}
+
+/* --- @mpx_loadb2cn@ --- *
+ *
+ * Arguments: @mpw *v, *vl@ = base and limit of destination vector
+ * @const void *pp@ = pointer to octet array
+ * @size_t sz@ = size of octet array
+ *
+ * Returns: ---
+ *
+ * Use: Loads a negative MP in an octet array, most significant octet
+ * first as two's complement. High-end octets are ignored if
+ * there isn't enough space for them. This probably means you
+ * chose this function wrongly.
+ */
+
+void mpx_loadb2cn(mpw *v, mpw *vl, const void *pp, size_t sz)
+{
+ unsigned n;
+ unsigned c = 1;
+ mpw w = 0;
+ const octet *p = pp, *q = p + sz;
+ unsigned bits = 0;
+
+ if (v >= vl)
+ return;
+ while (q > p) {
+ n = U8(~(*--q) + c);
+ c = !n;
+ w |= n << bits;
+ bits += 8;
+ if (bits >= MPW_BITS) {
+ *v++ = MPW(w);
+ w = n >> (MPW_BITS - bits + 8);
+ bits -= MPW_BITS;
+ if (v >= vl)
+ return;
+ }
+ }
+ *v++ = w;
+ MPX_ZERO(v, vl);
+}
+
/*----- Logical shifting --------------------------------------------------*/
/* --- @mpx_lsl@ --- *
/*----- Bitwise operations ------------------------------------------------*/
-/* --- @mpx_and@, @mpx_or@, @mpx_xor@, @mpx_not@ --- *
+/* --- @mpx_bitop@ --- *
*
* Arguments: @mpw *dv, *dvl@ = destination vector
* @const mpw *av, *avl@ = first source vector
*
* Returns: ---
*
- * Use; Does the obvious bitwise operations.
+ * Use; Provides the dyadic boolean functions.
*/
-#define MPX_BITBINOP(name, op) \
+#define MPX_BITBINOP(string) \
\
-void mpx_##name(mpw *dv, mpw *dvl, const mpw *av, const mpw *avl, \
- const mpw *bv, const mpw *bvl) \
+void mpx_bit##string(mpw *dv, mpw *dvl, const mpw *av, const mpw *avl, \
+ const mpw *bv, const mpw *bvl) \
{ \
MPX_SHRINK(av, avl); \
MPX_SHRINK(bv, bvl); \
mpw a, b; \
a = (av < avl) ? *av++ : 0; \
b = (bv < bvl) ? *bv++ : 0; \
- *dv++ = a op b; \
+ *dv++ = MPX_B##string(a, b); \
} \
}
-MPX_BITBINOP(and, &)
-MPX_BITBINOP(or, |)
-MPX_BITBINOP(xor, ^)
+MPX_DOBIN(MPX_BITBINOP)
void mpx_not(mpw *dv, mpw *dvl, const mpw *av, const mpw *avl)
{
return (ok);
}
+static int twocl(dstr *v)
+{
+ dstr d = DSTR_INIT;
+ mpw *m, *ml;
+ size_t sz;
+ int ok = 1;
+
+ sz = v[0].len; if (v[1].len > sz) sz = v[1].len;
+ dstr_ensure(&d, sz);
+
+ sz = MPW_RQ(sz);
+ m = xmalloc(MPWS(sz));
+ ml = m + sz;
+
+ mpx_loadl(m, ml, v[0].buf, v[0].len);
+ mpx_storel2cn(m, ml, d.buf, v[1].len);
+ if (memcmp(d.buf, v[1].buf, v[1].len)) {
+ dumpbits("\n*** storel2cn failed", d.buf, v[1].len);
+ ok = 0;
+ }
+
+ mpx_loadl2cn(m, ml, v[1].buf, v[1].len);
+ mpx_storel(m, ml, d.buf, v[0].len);
+ if (memcmp(d.buf, v[0].buf, v[0].len)) {
+ dumpbits("\n*** loadl2cn failed", d.buf, v[0].len);
+ ok = 0;
+ }
+
+ if (!ok) {
+ dumpbits("pos", v[0].buf, v[0].len);
+ dumpbits("neg", v[1].buf, v[1].len);
+ }
+
+ free(m);
+ dstr_destroy(&d);
+
+ return (ok);
+}
+
+static int twocb(dstr *v)
+{
+ dstr d = DSTR_INIT;
+ mpw *m, *ml;
+ size_t sz;
+ int ok = 1;
+
+ sz = v[0].len; if (v[1].len > sz) sz = v[1].len;
+ dstr_ensure(&d, sz);
+
+ sz = MPW_RQ(sz);
+ m = xmalloc(MPWS(sz));
+ ml = m + sz;
+
+ mpx_loadb(m, ml, v[0].buf, v[0].len);
+ mpx_storeb2cn(m, ml, d.buf, v[1].len);
+ if (memcmp(d.buf, v[1].buf, v[1].len)) {
+ dumpbits("\n*** storeb2cn failed", d.buf, v[1].len);
+ ok = 0;
+ }
+
+ mpx_loadb2cn(m, ml, v[1].buf, v[1].len);
+ mpx_storeb(m, ml, d.buf, v[0].len);
+ if (memcmp(d.buf, v[0].buf, v[0].len)) {
+ dumpbits("\n*** loadb2cn failed", d.buf, v[0].len);
+ ok = 0;
+ }
+
+ if (!ok) {
+ dumpbits("pos", v[0].buf, v[0].len);
+ dumpbits("neg", v[1].buf, v[1].len);
+ }
+
+ free(m);
+ dstr_destroy(&d);
+
+ return (ok);
+}
+
static int lsl(dstr *v)
{
mpw *a, *al;
static test_chunk defs[] = {
{ "load-store", loadstore, { &type_hex, 0 } },
+ { "2cl", twocl, { &type_hex, &type_hex, } },
+ { "2cb", twocb, { &type_hex, &type_hex, } },
{ "lsl", lsl, { &type_hex, &type_int, &type_hex, 0 } },
{ "lsr", lsr, { &type_hex, &type_int, &type_hex, 0 } },
{ "uadd", uadd, { &type_hex, &type_hex, &type_hex, 0 } },
projects / u / mdw / catacomb / blobdiff