+ mpd yy = (mpd)dd * q;
+ mpw yl;
+
+ if (yy > MPW_MAX)
+ yh += yy >> MPW_BITS;
+ yl = MPW(yy);
+
+ while (yh > rh || (yh == rh && yl > rrr)) {
+ q--;
+ yh -= d;
+ if (yl < dd)
+ yh--;
+ yl = MPW(yl - dd);
+ }
+ }
+
+ /* --- Remove a chunk from the dividend --- */
+
+ {
+ mpw *svv;
+ const mpw *dvv;
+ mpw mc = 0, sc = 0;
+
+ /* --- Calculate the size of the chunk --- *
+ *
+ * This does the whole job of calculating @r >> scale - qd@.
+ */
+
+ for (svv = rv + scale, dvv = dv;
+ dvv < dvl && svv < rvl;
+ svv++, dvv++) {
+ mpd x = (mpd)*dvv * (mpd)q + mc;
+ mc = x >> MPW_BITS;
+ x = (mpd)*svv - MPW(x) - sc;
+ *svv = MPW(x);
+ if (x >> MPW_BITS)
+ sc = 1;
+ else
+ sc = 0;
+ }
+
+ if (svv < rvl) {
+ mpd x = (mpd)*svv - mc - sc;
+ *svv++ = MPW(x);
+ if (x >> MPW_BITS)
+ sc = MPW_MAX;
+ else
+ sc = 0;
+ while (svv < rvl)
+ *svv++ = sc;
+ }
+
+ /* --- Fix if the quotient was too large --- *
+ *
+ * This doesn't seem to happen very often.
+ */
+
+ if (rvl[-1] > MPW_MAX / 2) {
+ mpx_uadd(rv + scale, rvl, rv + scale, rvl, dv, dvl);
+ q--;
+ }
+ }
+
+ /* --- Done for another iteration --- */
+
+ if (qvl - qv > scale)
+ qv[scale] = q;
+ r = rr;
+ rr = rrr;
+ }
+ }
+
+ /* --- Now fiddle with unnormalizing and things --- */
+
+ mpx_lsr(rv, rvl, rv, rvl, norm);
+}
+
+/* --- @mpx_udivn@ --- *
+ *
+ * Arguments: @mpw *qv, *qvl@ = storage for the quotient (may overlap
+ * dividend)
+ * @const mpw *rv, *rvl@ = dividend
+ * @mpw d@ = single-precision divisor
+ *
+ * Returns: Remainder after divison.
+ *
+ * Use: Performs a single-precision division operation.
+ */
+
+mpw mpx_udivn(mpw *qv, mpw *qvl, const mpw *rv, const mpw *rvl, mpw d)
+{
+ size_t i;
+ size_t ql = qvl - qv;
+ mpd r = 0;
+
+ i = rvl - rv;
+ while (i > 0) {
+ i--;
+ r = (r << MPW_BITS) | rv[i];
+ if (i < ql)
+ qv[i] = r / d;
+ r %= d;
+ }
+ return (MPW(r));
+}
+
+/*----- Test rig ----------------------------------------------------------*/
+
+#ifdef TEST_RIG
+
+#include <mLib/alloc.h>
+#include <mLib/dstr.h>
+#include <mLib/quis.h>
+#include <mLib/testrig.h>
+
+#include "mpscan.h"
+
+#define ALLOC(v, vl, sz) do { \
+ size_t _sz = (sz); \
+ mpw *_vv = xmalloc(MPWS(_sz)); \
+ mpw *_vvl = _vv + _sz; \
+ (v) = _vv; \
+ (vl) = _vvl; \
+} while (0)
+
+#define LOAD(v, vl, d) do { \
+ const dstr *_d = (d); \
+ mpw *_v, *_vl; \
+ ALLOC(_v, _vl, MPW_RQ(_d->len)); \
+ mpx_loadb(_v, _vl, _d->buf, _d->len); \
+ (v) = _v; \
+ (vl) = _vl; \
+} while (0)
+
+#define MAX(x, y) ((x) > (y) ? (x) : (y))
+
+static void dumpbits(const char *msg, const void *pp, size_t sz)
+{
+ const octet *p = pp;
+ fputs(msg, stderr);
+ for (; sz; sz--)
+ fprintf(stderr, " %02x", *p++);
+ fputc('\n', stderr);
+}
+
+static void dumpmp(const char *msg, const mpw *v, const mpw *vl)
+{
+ fputs(msg, stderr);
+ MPX_SHRINK(v, vl);
+ while (v < vl)
+ fprintf(stderr, " %08lx", (unsigned long)*--vl);
+ fputc('\n', stderr);
+}
+
+static int chkscan(const mpw *v, const mpw *vl,
+ const void *pp, size_t sz, int step)
+{
+ mpscan mps;
+ const octet *p = pp;
+ unsigned bit = 0;
+ int ok = 1;
+
+ mpscan_initx(&mps, v, vl);
+ while (sz) {
+ unsigned x = *p;
+ int i;
+ p += step;
+ for (i = 0; i < 8 && MPSCAN_STEP(&mps); i++) {
+ if (MPSCAN_BIT(&mps) != (x & 1)) {
+ fprintf(stderr,
+ "\n*** error, step %i, bit %u, expected %u, found %u\n",
+ step, bit, x & 1, MPSCAN_BIT(&mps));
+ ok = 0;
+ }
+ x >>= 1;
+ bit++;
+ }
+ sz--;
+ }
+
+ return (ok);
+}
+
+static int loadstore(dstr *v)
+{
+ dstr d = DSTR_INIT;
+ size_t sz = MPW_RQ(v->len) * 2, diff;
+ mpw *m, *ml;
+ int ok = 1;
+
+ dstr_ensure(&d, v->len);
+ m = xmalloc(MPWS(sz));
+
+ for (diff = 0; diff < sz; diff += 5) {
+ size_t oct;
+
+ ml = m + sz - diff;
+
+ mpx_loadl(m, ml, v->buf, v->len);
+ if (!chkscan(m, ml, v->buf, v->len, +1))
+ ok = 0;
+ MPX_OCTETS(oct, m, ml);
+ mpx_storel(m, ml, d.buf, d.sz);
+ if (memcmp(d.buf, v->buf, oct) != 0) {
+ dumpbits("\n*** storel failed", d.buf, d.sz);
+ ok = 0;
+ }
+
+ mpx_loadb(m, ml, v->buf, v->len);
+ if (!chkscan(m, ml, v->buf + v->len - 1, v->len, -1))
+ ok = 0;
+ MPX_OCTETS(oct, m, ml);
+ mpx_storeb(m, ml, d.buf, d.sz);
+ if (memcmp(d.buf + d.sz - oct, v->buf + v->len - oct, oct) != 0) {
+ dumpbits("\n*** storeb failed", d.buf, d.sz);
+ ok = 0;
+ }
+ }
+
+ if (!ok)
+ dumpbits("input data", v->buf, v->len);
+
+ free(m);
+ dstr_destroy(&d);
+ 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;
+ int n = *(int *)v[1].buf;
+ mpw *c, *cl;
+ mpw *d, *dl;
+ int ok = 1;
+
+ LOAD(a, al, &v[0]);
+ LOAD(c, cl, &v[2]);
+ ALLOC(d, dl, al - a + (n + MPW_BITS - 1) / MPW_BITS);
+
+ mpx_lsl(d, dl, a, al, n);
+ if (!mpx_ueq(d, dl, c, cl)) {
+ fprintf(stderr, "\n*** lsl(%i) failed\n", n);
+ dumpmp(" a", a, al);
+ dumpmp("expected", c, cl);
+ dumpmp(" result", d, dl);
+ ok = 0;
+ }
+
+ free(a); free(c); free(d);
+ return (ok);