summaryrefslogtreecommitdiff
path: root/lisp/mp/mpi.c
diff options
context:
space:
mode:
authorKaleb Keithley <kaleb@freedesktop.org>2003-11-14 16:49:22 +0000
committerKaleb Keithley <kaleb@freedesktop.org>2003-11-14 16:49:22 +0000
commit0a193e032ba1ecf3f003e027e833dc9d274cb740 (patch)
treea1dcc00cb7f5d26e437e05e658c38fc323fe919d /lisp/mp/mpi.c
Initial revision
Diffstat (limited to 'lisp/mp/mpi.c')
-rw-r--r--lisp/mp/mpi.c1656
1 files changed, 1656 insertions, 0 deletions
diff --git a/lisp/mp/mpi.c b/lisp/mp/mpi.c
new file mode 100644
index 0000000..506dc7e
--- /dev/null
+++ b/lisp/mp/mpi.c
@@ -0,0 +1,1656 @@
+/*
+ * Copyright (c) 2002 by The XFree86 Project, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE XFREE86 PROJECT BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of the XFree86 Project shall
+ * not be used in advertising or otherwise to promote the sale, use or other
+ * dealings in this Software without prior written authorization from the
+ * XFree86 Project.
+ *
+ * Author: Paulo César Pereira de Andrade
+ */
+
+/* $XFree86: xc/programs/xedit/lisp/mp/mpi.c,v 1.12 2002/11/20 07:44:43 paulo Exp $ */
+
+#include "mp.h"
+
+/*
+ * Prototypes
+ */
+ /* do the hard work of mpi_add and mpi_sub */
+static void mpi_addsub(mpi *rop, mpi *op1, mpi *op2, int sub);
+
+ /* logical functions implementation */
+static INLINE BNS mpi_logic(BNS op1, BNS op2, BNS op);
+static void mpi_log(mpi *rop, mpi *op1, mpi *op2, BNS op);
+
+ /* internal mpi_seti, whithout memory allocation */
+static void _mpi_seti(mpi *rop, long si);
+
+/*
+ * Initialization
+ */
+static BNS onedig[1] = { 1 };
+static mpi mpone = { 1, 1, 0, (BNS*)&onedig };
+
+/*
+ * Implementation
+ */
+void
+mpi_init(mpi *op)
+{
+ op->sign = 0;
+ op->size = op->alloc = 1;
+ op->digs = mp_malloc(sizeof(BNS));
+ op->digs[0] = 0;
+}
+
+void
+mpi_clear(mpi *op)
+{
+ op->sign = 0;
+ op->size = op->alloc = 0;
+ mp_free(op->digs);
+}
+
+void
+mpi_set(mpi *rop, mpi *op)
+{
+ if (rop != op) {
+ if (rop->alloc < op->size) {
+ rop->digs = mp_realloc(rop->digs, sizeof(BNS) * op->size);
+ rop->alloc = op->size;
+ }
+ rop->size = op->size;
+ memcpy(rop->digs, op->digs, sizeof(BNS) * op->size);
+ rop->sign = op->sign;
+ }
+}
+
+void
+mpi_seti(mpi *rop, long si)
+{
+ unsigned long ui;
+ int sign = si < 0;
+ int size;
+
+ if (si == MINSLONG) {
+ ui = MINSLONG;
+ size = 2;
+ }
+ else {
+ if (sign)
+ ui = -si;
+ else
+ ui = si;
+ if (ui < CARRY)
+ size = 1;
+ else
+ size = 2;
+ }
+
+ if (rop->alloc < size) {
+ rop->digs = mp_realloc(rop->digs, sizeof(BNS) * size);
+ rop->alloc = size;
+ }
+ rop->size = size;
+
+ /* store data in small mp integer */
+ rop->digs[0] = (BNS)ui;
+ if (size > 1)
+ rop->digs[1] = (BNS)(ui >> BNSBITS);
+ rop->size = size;
+
+ /* adjust result sign */
+ rop->sign = sign;
+}
+
+static void
+_mpi_seti(mpi *rop, long si)
+{
+ unsigned long ui;
+ int sign = si < 0;
+ int size;
+
+ if (si == MINSLONG) {
+ ui = MINSLONG;
+ size = 2;
+ }
+ else {
+ if (sign)
+ ui = -si;
+ else
+ ui = si;
+ if (ui < CARRY)
+ size = 1;
+ else
+ size = 2;
+ }
+
+ rop->digs[0] = (BNS)ui;
+ if (size > 1)
+ rop->digs[1] = (BNS)(ui >> BNSBITS);
+ rop->size = size;
+
+ rop->sign = sign;
+}
+
+void
+mpi_setd(mpi *rop, double d)
+{
+ long i;
+ double mantissa;
+ int shift, exponent;
+ BNI size;
+
+ if (isnan(d))
+ d = 0.0;
+ else if (!finite(d))
+ d = copysign(1.0, d) * DBL_MAX;
+
+ /* check if number is larger than 1 */
+ if (fabs(d) < 1.0) {
+ rop->digs[0] = 0;
+ rop->size = 1;
+ rop->sign = d < 0.0;
+
+ return;
+ }
+
+ mantissa = frexp(d, &exponent);
+ if (mantissa < 0)
+ mantissa = -mantissa;
+
+ size = (exponent + (BNSBITS - 1)) / BNSBITS;
+ shift = BNSBITS - (exponent & (BNSBITS - 1));
+
+ /* adjust amount of memory */
+ if (rop->alloc < size) {
+ rop->digs = mp_realloc(rop->digs, sizeof(BNS) * size);
+ rop->alloc = size;
+ }
+ rop->size = size;
+
+ /* adjust the exponent */
+ if (shift < BNSBITS)
+ mantissa = ldexp(mantissa, -shift);
+
+ /* convert double */
+ for (i = size - 1; i >= 0 && mantissa != 0.0; i--) {
+ mantissa = ldexp(mantissa, BNSBITS);
+ rop->digs[i] = (BNS)mantissa;
+ mantissa -= rop->digs[i];
+ }
+ for (; i >= 0; i--)
+ rop->digs[i] = 0;
+
+ /* normalize */
+ if (size > 1 && rop->digs[size - 1] == 0)
+ --rop->size;
+
+ rop->sign = d < 0.0;
+}
+
+/* how many BNS in the given base, log(base) / log(CARRY) */
+#ifdef LONG64
+static double str_bases[37] = {
+ 0.0000000000000000, 0.0000000000000000, 0.0312500000000000,
+ 0.0495300781475362, 0.0625000000000000, 0.0725602529652301,
+ 0.0807800781475362, 0.0877298413143002, 0.0937500000000000,
+ 0.0990601562950723, 0.1038102529652301, 0.1081072380824156,
+ 0.1120300781475362, 0.1156387411919092, 0.1189798413143002,
+ 0.1220903311127662, 0.1250000000000000, 0.1277332137890731,
+ 0.1303101562950723, 0.1327477347951120, 0.1350602529652300,
+ 0.1372599194618363, 0.1393572380824156, 0.1413613111267817,
+ 0.1432800781475362, 0.1451205059304602, 0.1468887411919092,
+ 0.1485902344426084, 0.1502298413143002, 0.1518119060977367,
+ 0.1533403311127662, 0.1548186346995899, 0.1562500000000000,
+ 0.1576373162299517, 0.1589832137890731, 0.1602900942795302,
+ 0.1615601562950723,
+};
+#else
+static double str_bases[37] = {
+ 0.0000000000000000, 0.0000000000000000, 0.0625000000000000,
+ 0.0990601562950723, 0.1250000000000000, 0.1451205059304602,
+ 0.1615601562950723, 0.1754596826286003, 0.1875000000000000,
+ 0.1981203125901446, 0.2076205059304602, 0.2162144761648311,
+ 0.2240601562950723, 0.2312774823838183, 0.2379596826286003,
+ 0.2441806622255325, 0.2500000000000000, 0.2554664275781462,
+ 0.2606203125901445, 0.2654954695902241, 0.2701205059304602,
+ 0.2745198389236725, 0.2787144761648311, 0.2827226222535633,
+ 0.2865601562950723, 0.2902410118609203, 0.2937774823838183,
+ 0.2971804688852168, 0.3004596826286003, 0.3036238121954733,
+ 0.3066806622255324, 0.3096372693991797, 0.3125000000000000,
+ 0.3152746324599034, 0.3179664275781462, 0.3205801885590604,
+ 0.3231203125901446,
+};
+#endif
+
+void
+mpi_setstr(mpi *rop, char *str, int base)
+{
+ long i; /* counter */
+ int sign; /* result sign */
+ BNI carry; /* carry value */
+ BNI value; /* temporary value */
+ BNI size; /* size of result */
+ char *ptr; /* end of valid input */
+
+ /* initialization */
+ sign = 0;
+ carry = 0;
+
+ /* skip leading spaces */
+ while (isspace(*str))
+ ++str;
+
+ /* check if sign supplied */
+ if (*str == '-') {
+ sign = 1;
+ ++str;
+ }
+ else if (*str == '+')
+ ++str;
+
+ /* skip leading zeros */
+ while (*str == '0')
+ ++str;
+
+ ptr = str;
+ while (*ptr) {
+ if (*ptr >= '0' && *ptr <= '9') {
+ if (*ptr - '0' >= base)
+ break;
+ }
+ else if (*ptr >= 'A' && *ptr <= 'Z') {
+ if (*ptr - 'A' + 10 >= base)
+ break;
+ }
+ else if (*ptr >= 'a' && *ptr <= 'z') {
+ if (*ptr - 'a' + 10 >= base)
+ break;
+ }
+ else
+ break;
+ ++ptr;
+ }
+
+ /* resulting size */
+ size = (ptr - str) * str_bases[base] + 1;
+
+ /* make sure rop has enough storage */
+ if (rop->alloc < size) {
+ rop->digs = mp_realloc(rop->digs, size * sizeof(BNS));
+ rop->alloc = size;
+ }
+ rop->size = size;
+
+ /* initialize rop to zero */
+ memset(rop->digs, '\0', size * sizeof(BNS));
+
+ /* set result sign */
+ rop->sign = sign;
+
+ /* convert string */
+ for (; str < ptr; str++) {
+ value = *str;
+ if (islower(value))
+ value = toupper(value);
+ value = value > '9' ? value - 'A' + 10 : value - '0';
+ value += rop->digs[0] * base;
+ carry = value >> BNSBITS;
+ rop->digs[0] = (BNS)value;
+ for (i = 1; i < size; i++) {
+ value = (BNI)rop->digs[i] * base + carry;
+ carry = value >> BNSBITS;
+ rop->digs[i] = (BNS)value;
+ }
+ }
+
+ /* normalize */
+ if (rop->size > 1 && rop->digs[rop->size - 1] == 0)
+ --rop->size;
+}
+
+void
+mpi_add(mpi *rop, mpi *op1, mpi *op2)
+{
+ mpi_addsub(rop, op1, op2, 0);
+}
+
+void
+mpi_addi(mpi *rop, mpi *op1, long op2)
+{
+ BNS digs[2];
+ mpi op;
+
+ op.digs = (BNS*)digs;
+ _mpi_seti(&op, op2);
+
+ mpi_addsub(rop, op1, &op, 0);
+}
+
+void
+mpi_sub(mpi *rop, mpi *op1, mpi *op2)
+{
+ mpi_addsub(rop, op1, op2, 1);
+}
+
+void
+mpi_subi(mpi *rop, mpi *op1, long op2)
+{
+ BNS digs[2];
+ mpi op;
+
+ op.digs = (BNS*)digs;
+ _mpi_seti(&op, op2);
+
+ mpi_addsub(rop, op1, &op, 1);
+}
+
+static void
+mpi_addsub(mpi *rop, mpi *op1, mpi *op2, int sub)
+{
+ long xlen; /* maximum result size */
+
+ if (sub ^ (op1->sign == op2->sign)) {
+ /* plus one for possible carry */
+ xlen = MAX(op1->size, op2->size) + 1;
+ if (rop->alloc < xlen) {
+ rop->digs = mp_realloc(rop->digs, sizeof(BNS) * xlen);
+ rop->alloc = xlen;
+ }
+ rop->size = mp_add(rop->digs, op1->digs, op2->digs,
+ op1->size, op2->size);
+ rop->sign = op1->sign;
+ }
+ else {
+ long cmp; /* check for larger operator */
+
+ cmp = mpi_cmpabs(op1, op2);
+ if (cmp == 0) {
+ rop->digs[0] = 0;
+ rop->size = 1;
+ rop->sign = 0;
+ }
+ else {
+ xlen = MAX(op1->size, op2->size);
+ if (rop->alloc < xlen) {
+ rop->digs = mp_realloc(rop->digs, sizeof(BNS) * xlen);
+ rop->alloc = xlen;
+ }
+ if (cmp > 0) {
+ rop->size = mp_sub(rop->digs, op1->digs, op2->digs,
+ op1->size, op2->size);
+ rop->sign = op1->sign;
+ }
+ else {
+ rop->size = mp_sub(rop->digs, op2->digs, op1->digs,
+ op2->size, op1->size);
+ rop->sign = sub ^ op2->sign;
+ }
+ }
+ }
+}
+
+void
+mpi_mul(mpi *rop, mpi *op1, mpi *op2)
+{
+ int sign; /* sign flag */
+ BNS *digs; /* result data */
+ long xsize; /* result size */
+
+ /* get result sign */
+ sign = op1->sign ^ op2->sign;
+
+ /* check for special cases */
+ if (op1->size == 1) {
+ if (*op1->digs == 0) {
+ /* multiply by 0 */
+ mpi_seti(rop, 0);
+ return;
+ }
+ else if (*op1->digs == 1) {
+ /* multiply by +-1 */
+ if (rop->alloc < op2->size) {
+ rop->digs = mp_realloc(rop->digs, sizeof(BNS) * op2->size);
+ rop->alloc = op2->size;
+ }
+ rop->size = op2->size;
+ memmove(rop->digs, op2->digs, sizeof(BNS) * op2->size);
+ rop->sign = op2->size > 1 || *op2->digs ? sign : 0;
+
+ return;
+ }
+ }
+ else if (op2->size == 1) {
+ if (*op2->digs == 0) {
+ /* multiply by 0 */
+ mpi_seti(rop, 0);
+ return;
+ }
+ else if (*op2->digs == 1) {
+ /* multiply by +-1 */
+ if (rop->alloc < op1->size) {
+ rop->digs = mp_realloc(rop->digs, sizeof(BNS) * op1->size);
+ rop->alloc = op1->size;
+ }
+ rop->size = op1->size;
+ memmove(rop->digs, op1->digs, sizeof(BNS) * op1->size);
+ rop->sign = op1->size > 1 || *op1->digs ? sign : 0;
+
+ return;
+ }
+ }
+
+ /* allocate result data and set it to zero */
+ xsize = op1->size + op2->size;
+ if (rop->digs == op1->digs || rop->digs == op2->digs)
+ /* rop is also an operand */
+ digs = mp_calloc(1, sizeof(BNS) * xsize);
+ else {
+ if (rop->alloc < xsize) {
+ rop->digs = mp_realloc(rop->digs, sizeof(BNS) * xsize);
+ rop->alloc = xsize;
+ }
+ digs = rop->digs;
+ memset(digs, '\0', sizeof(BNS) * xsize);
+ }
+
+ /* multiply operands */
+ xsize = mp_mul(digs, op1->digs, op2->digs, op1->size, op2->size);
+
+ /* store result in rop */
+ if (digs != rop->digs) {
+ /* if rop was an operand, free old data */
+ mp_free(rop->digs);
+ rop->digs = digs;
+ }
+ rop->size = xsize;
+
+ /* set result sign */
+ rop->sign = sign;
+}
+
+void
+mpi_muli(mpi *rop, mpi *op1, long op2)
+{
+ BNS digs[2];
+ mpi op;
+
+ op.digs = (BNS*)digs;
+ _mpi_seti(&op, op2);
+
+ mpi_mul(rop, op1, &op);
+}
+
+void
+mpi_div(mpi *rop, mpi *num, mpi *den)
+{
+ mpi_divqr(rop, NULL, num, den);
+}
+
+void
+mpi_rem(mpi *rop, mpi *num, mpi *den)
+{
+ mpi_divqr(NULL, rop, num, den);
+}
+
+/*
+ * Could/should be changed to not allocate qdigs if qrop is NULL
+ * Performance wouldn't suffer too much with a test on every loop iteration.
+ */
+void
+mpi_divqr(mpi *qrop, mpi *rrop, mpi *num, mpi *den)
+{
+ long i, j; /* counters */
+ int qsign; /* sign of quotient */
+ int rsign; /* sign of remainder */
+ BNI qsize; /* size of quotient */
+ BNI rsize; /* size of remainder */
+ BNS qest; /* estimative of quotient value */
+ BNS *qdigs, *rdigs; /* work copy or result */
+ BNS *ndigs, *ddigs; /* work copy or divisor and dividend */
+ BNI value; /* temporary result */
+ long svalue; /* signed temporary result (2's complement) */
+ BNS carry, scarry, denorm; /* carry and normalization */
+ BNI dpos, npos; /* offsets in data */
+
+ /* get signs */
+ rsign = num->sign;
+ qsign = rsign ^ den->sign;
+
+ /* check for special case */
+ if (num->size < den->size) {
+ /* quotient is zero and remainder is numerator */
+ if (rrop && rrop->digs != num->digs) {
+ if (rrop->alloc < num->size) {
+ rrop->digs = mp_realloc(rrop->digs, sizeof(BNS) * num->size);
+ rrop->alloc = num->size;
+ }
+ rrop->size = num->size;
+ memcpy(rrop->digs, num->digs, sizeof(BNS) * num->size);
+ rrop->sign = rsign;
+ }
+ if (qrop)
+ mpi_seti(qrop, 0);
+
+ return;
+ }
+
+ /* estimate result sizes */
+ rsize = den->size;
+ qsize = num->size - den->size + 1;
+
+ /* offsets */
+ npos = num->size - 1;
+ dpos = den->size - 1;
+
+ /* allocate space for quotient and remainder */
+ if (qrop == NULL || qrop->digs == num->digs || qrop->digs == den->digs)
+ qdigs = mp_calloc(1, sizeof(BNS) * qsize);
+ else {
+ if (qrop->alloc < qsize) {
+ qrop->digs = mp_realloc(qrop->digs, sizeof(BNS) * qsize);
+ qrop->alloc = qsize;
+ }
+ memset(qrop->digs, '\0', sizeof(BNS) * qsize);
+ qdigs = qrop->digs;
+ }
+ if (rrop) {
+ if (rrop->digs == num->digs || rrop->digs == den->digs)
+ rdigs = mp_calloc(1, sizeof(BNS) * rsize);
+ else {
+ if (rrop->alloc < rsize) {
+ rrop->digs = mp_realloc(rrop->digs, sizeof(BNS) * rsize);
+ rrop->alloc = rsize;
+ }
+ memset(rrop->digs, '\0', sizeof(BNS) * rsize);
+ rdigs = rrop->digs;
+ }
+ }
+ else
+ rdigs = NULL; /* fix gcc warning */
+
+ /* special case, only one word in divisor */
+ if (dpos == 0) {
+ for (carry = 0, i = npos; i >= 0; i--) {
+ value = ((BNI)carry << BNSBITS) + num->digs[i];
+ qdigs[i] = (BNS)(value / den->digs[0]);
+ carry = (BNS)(value % den->digs[0]);
+ }
+ if (rrop)
+ rdigs[0] = carry;
+
+ goto mpi_divqr_done;
+ }
+
+ /* make work copy of numerator */
+ ndigs = mp_malloc(sizeof(BNS) * (num->size + 1));
+ /* allocate one extra word an update offset */
+ memcpy(ndigs, num->digs, sizeof(BNS) * num->size);
+ ndigs[num->size] = 0;
+ ++npos;
+
+ /* normalize */
+ denorm = (BNS)((BNI)CARRY / ((BNI)(den->digs[dpos]) + 1));
+
+ if (denorm > 1) {
+ /* i <= num->size because ndigs has an extra word */
+ for (carry = 0, i = 0; i <= num->size; i++) {
+ value = ndigs[i] * (BNI)denorm + carry;
+ ndigs[i] = (BNS)value;
+ carry = (BNS)(value >> BNSBITS);
+ }
+ /* make work copy of denominator */
+ ddigs = mp_malloc(sizeof(BNS) * den->size);
+ memcpy(ddigs, den->digs, sizeof(BNS) * den->size);
+ for (carry = 0, i = 0; i < den->size; i++) {
+ value = ddigs[i] * (BNI)denorm + carry;
+ ddigs[i] = (BNS)value;
+ carry = (BNS)(value >> BNSBITS);
+ }
+ }
+ else
+ /* only allocate copy of denominator if going to change it */
+ ddigs = den->digs;
+
+ /* divide mp integers */
+ for (j = qsize - 1; j >= 0; j--, npos--) {
+ /* estimate quotient */
+ if (ndigs[npos] == ddigs[dpos])
+ qest = (BNS)SMASK;
+ else
+ qest = (BNS)((((BNI)(ndigs[npos]) << 16) + ndigs[npos - 1]) /
+ ddigs[dpos]);
+
+ while ((value = ((BNI)(ndigs[npos]) << 16) + ndigs[npos - 1] -
+ qest * (BNI)(ddigs[dpos])) < CARRY &&
+ ddigs[dpos - 1] * (BNI)qest >
+ (value << BNSBITS) + ndigs[npos - 2])
+ --qest;
+
+ /* multiply and subtract */
+ carry = scarry = 0;
+ for (i = 0; i < den->size; i++) {
+ value = qest * (BNI)ddigs[i] + carry;
+ carry = (BNS)(value >> BNSBITS);
+ svalue = (long)ndigs[npos - dpos + i - 1] - (long)(value & SMASK) -
+ (long)scarry;
+ ndigs[npos - dpos + i - 1] = (BNS)svalue;
+ scarry = svalue < 0;
+ }
+
+ svalue = (long)ndigs[npos] - (long)(carry & SMASK) - (long)scarry;
+ ndigs[npos] = (BNS)svalue;
+
+ if (svalue & LMASK) {
+ /* quotient too big */
+ --qest;
+ carry = 0;
+ for (i = 0; i < den->size; i++) {
+ value = ndigs[npos - dpos + i - 1] + (BNI)carry + (BNI)ddigs[i];
+ ndigs[npos - dpos + i - 1] = (BNS)value;
+ carry = (BNS)(value >> BNSBITS);
+ }
+ ndigs[npos] += carry;
+ }
+
+ qdigs[j] = qest;
+ }
+
+ /* calculate remainder */
+ if (rrop) {
+ for (carry = 0, j = dpos; j >= 0; j--) {
+ value = ((BNI)carry << BNSBITS) + ndigs[j];
+ rdigs[j] = (BNS)(value / denorm);
+ carry = (BNS)(value % denorm);
+ }
+ }
+
+ mp_free(ndigs);
+ if (ddigs != den->digs)
+ mp_free(ddigs);
+
+mpi_divqr_done:
+ if (rrop) {
+ if (rrop->digs != rdigs)
+ mp_free(rrop->digs);
+ /* normalize remainder */
+ for (i = rsize - 1; i >= 0; i--)
+ if (rdigs[i] != 0)
+ break;
+ if (i != rsize - 1) {
+ if (i < 0) {
+ rsign = 0;
+ rsize = 1;
+ }
+ else
+ rsize = i + 1;
+ }
+ rrop->digs = rdigs;
+ rrop->sign = rsign;
+ rrop->size = rsize;
+ }
+
+ /* normalize quotient */
+ if (qrop) {
+ if (qrop->digs != qdigs)
+ mp_free(qrop->digs);
+ for (i = qsize - 1; i >= 0; i--)
+ if (qdigs[i] != 0)
+ break;
+ if (i != qsize - 1) {
+ if (i < 0) {
+ qsign = 0;
+ qsize = 1;
+ }
+ else
+ qsize = i + 1;
+ }
+ qrop->digs = qdigs;
+ qrop->sign = qsign;
+ qrop->size = qsize;
+ }
+ else
+ mp_free(qdigs);
+}
+
+long
+mpi_divqri(mpi *qrop, mpi *num, long den)
+{
+ BNS ddigs[2];
+ mpi dop, rrop;
+ long remainder;
+
+ dop.digs = (BNS*)ddigs;
+ _mpi_seti(&dop, den);
+
+ memset(&rrop, '\0', sizeof(mpi));
+ mpi_init(&rrop);
+ mpi_divqr(qrop, &rrop, num, &dop);
+ remainder = rrop.digs[0];
+ if (rrop.size > 1)
+ remainder |= (BNI)(rrop.digs[1]) << BNSBITS;
+ if (rrop.sign)
+ remainder = -remainder;
+ mpi_clear(&rrop);
+
+ return (remainder);
+}
+
+void
+mpi_divi(mpi *rop, mpi *num, long den)
+{
+ BNS ddigs[2];
+ mpi dop;
+
+ dop.digs = (BNS*)ddigs;
+ _mpi_seti(&dop, den);
+
+ mpi_divqr(rop, NULL, num, &dop);
+}
+
+long
+mpi_remi(mpi *num, long den)
+{
+ return (mpi_divqri(NULL, num, den));
+}
+
+void
+mpi_mod(mpi *rop, mpi *num, mpi *den)
+{
+ mpi_rem(rop, num, den);
+ if (num->sign ^ den->sign)
+ mpi_add(rop, rop, den);
+}
+
+long
+mpi_modi(mpi *num, long den)
+{
+ long remainder;
+
+ remainder = mpi_remi(num, den);
+ if (num->sign ^ (den < 0))
+ remainder += den;
+
+ return (remainder);
+}
+
+void
+mpi_gcd(mpi *rop, mpi *num, mpi *den)
+{
+ long cmp;
+ mpi rem;
+
+ /* check if result already given */
+ cmp = mpi_cmpabs(num, den);
+
+ /* check if num is equal to den or if num is zero */
+ if (cmp == 0 || (num->size == 1 && num->digs[0] == 0)) {
+ mpi_set(rop, den);
+ rop->sign = 0;
+ return;
+ }
+ /* check if den is not zero */
+ if (den->size == 1 && den->digs[0] == 0) {
+ mpi_set(rop, num);
+ rop->sign = 0;
+ return;
+ }
+
+ /* don't call mpi_init, relies on realloc(0, size) == malloc(size) */
+ memset(&rem, '\0', sizeof(mpi));
+
+ /* if num larger than den */
+ if (cmp > 0) {
+ mpi_rem(&rem, num, den);
+ if (rem.size == 1 && rem.digs[0] == 0) {
+ /* exact division */
+ mpi_set(rop, den);
+ rop->sign = 0;
+ mpi_clear(&rem);
+ return;
+ }
+ mpi_set(rop, den);
+ }
+ else {
+ mpi_rem(&rem, den, num);
+ if (rem.size == 1 && rem.digs[0] == 0) {
+ /* exact division */
+ mpi_set(rop, num);
+ rop->sign = 0;
+ mpi_clear(&rem);
+ return;
+ }
+ mpi_set(rop, num);
+ }
+
+ /* loop using positive values */
+ rop->sign = rem.sign = 0;
+
+ /* cannot optimize this inverting rem/rop assignment earlier
+ * because rop mais be an operand */
+ mpi_swap(rop, &rem);
+
+ /* Euclides algorithm */
+ for (;;) {
+ mpi_rem(&rem, &rem, rop);
+ if (rem.size == 1 && rem.digs[0] == 0)
+ break;
+ mpi_swap(rop, &rem);
+ }
+ mpi_clear(&rem);
+}
+
+void
+mpi_lcm(mpi *rop, mpi *num, mpi *den)
+{
+ mpi gcd;
+
+ /* check for zero operand */
+ if ((num->size == 1 && num->digs[0] == 0) ||
+ (den->size == 1 && den->digs[0] == 0)) {
+ rop->digs[0] = 0;
+ rop->sign = 0;
+ return;
+ }
+
+ /* don't call mpi_init, relies on realloc(0, size) == malloc(size) */
+ memset(&gcd, '\0', sizeof(mpi));
+
+ mpi_gcd(&gcd, num, den);
+ mpi_div(&gcd, den, &gcd);
+ mpi_mul(rop, &gcd, num);
+ rop->sign = 0;
+
+ mpi_clear(&gcd);
+}
+
+void
+mpi_pow(mpi *rop, mpi *op, unsigned long exp)
+{
+ mpi zop, top;
+
+ if (exp == 2) {
+ mpi_mul(rop, op, op);
+ return;
+ }
+ /* check for op**0 */
+ else if (exp == 0) {
+ rop->digs[0] = 1;
+ rop->size = 1;
+ rop->sign = 0;
+ return;
+ }
+ else if (exp == 1) {
+ mpi_set(rop, op);
+ return;
+ }
+ else if (op->size == 1) {
+ if (op->digs[0] == 0) {
+ mpi_seti(rop, 0);
+ return;
+ }
+ else if (op->digs[0] == 1) {
+ mpi_seti(rop, op->sign && (exp & 1) ? -1 : 1);
+ return;
+ }
+ }
+
+ memset(&zop, '\0', sizeof(mpi));
+ memset(&top, '\0', sizeof(mpi));
+ mpi_set(&zop, op);
+ mpi_set(&top, op);
+ for (--exp; exp; exp >>= 1) {
+ if (exp & 1)
+ mpi_mul(&zop, &top, &zop);
+ mpi_mul(&top, &top, &top);
+ }
+
+ mpi_clear(&top);
+ rop->sign = zop.sign;
+ mp_free(rop->digs);
+ rop->digs = zop.digs;
+ rop->size = zop.size;
+}
+
+/* Find integer root of given number using the iteration
+ * x{n+1} = ((K-1) * x{n} + N / x{n}^(K-1)) / K
+ */
+int
+mpi_root(mpi *rop, mpi *op, unsigned long nth)
+{
+ long bits, cmp;
+ int exact;
+ int sign;
+ mpi *r, t, temp, quot, old, rem;
+
+ sign = op->sign;
+
+ /* divide by zero op**1/0 */
+ if (nth == 0) {
+ int one = 1, zero = 0;
+ one = one / zero;
+ }
+ /* result is complex */
+ if (sign && !(nth & 1)) {
+ int one = 1, zero = 0;
+ one = one / zero;
+ }
+
+ /* special case op**1/1 = op */
+ if (nth == 1) {
+ mpi_set(rop, op);
+ return (1);
+ }
+
+ bits = mpi_getsize(op, 2) - 2;
+
+ if (bits < 0 || bits / nth == 0) {
+ /* integral root is surely less than 2 */
+ exact = op->size == 1 && (op->digs[0] == 1 || op->digs[0] == 0);
+ mpi_seti(rop, sign ? -1 : op->digs[0] == 0 ? 0 : 1);
+
+ return (exact == 1);
+ }
+
+ /* initialize */
+ if (rop != op)
+ r = rop;
+ else {
+ r = &t;
+ memset(r, '\0', sizeof(mpi));
+ }
+ memset(&temp, '\0', sizeof(mpi));
+ memset(&quot, '\0', sizeof(mpi));
+ memset(&old, '\0', sizeof(mpi));
+ memset(&rem, '\0', sizeof(mpi));
+
+ if (sign)
+ r->sign = 0;
+
+ /* root aproximation */
+ mpi_ash(r, op, -(bits - (bits / nth)));
+
+ for (;;) {
+ mpi_pow(&temp, r, nth - 1);
+ mpi_divqr(&quot, &rem, op, &temp);
+ cmp = mpi_cmpabs(r, &quot);
+ if (cmp == 0) {
+ exact = mpi_cmpi(&rem, 0) == 0;
+ break;
+ }
+ else if (cmp < 0) {
+ if (mpi_cmpabs(r, &old) == 0) {
+ exact = 0;
+ break;
+ }
+ mpi_set(&old, r);
+ }
+ mpi_muli(&temp, r, nth - 1);
+ mpi_add(&quot, &quot, &temp);
+ mpi_divi(r, &quot, nth);
+ }
+
+ mpi_clear(&temp);
+ mpi_clear(&quot);
+ mpi_clear(&old);
+ mpi_clear(&rem);
+ if (r != rop) {
+ mpi_set(rop, r);
+ mpi_clear(r);
+ }
+ rop->sign = sign;
+
+ return (exact);
+}
+
+/*
+ * Find square root using the iteration:
+ * x{n+1} = (x{n}+N/x{n})/2
+ */
+int
+mpi_sqrt(mpi *rop, mpi *op)
+{
+ long bits, cmp;
+ int exact;
+ mpi *r, t, quot, rem, old;
+
+ /* result is complex */
+ if (op->sign) {
+ int one = 1, zero = 0;
+ one = one / zero;
+ }
+
+ bits = mpi_getsize(op, 2) - 2;
+
+ if (bits < 2) {
+ /* integral root is surely less than 2 */
+ exact = op->size == 1 && (op->digs[0] == 1 || op->digs[0] == 0);
+ mpi_seti(rop, op->digs[0] == 0 ? 0 : 1);
+
+ return (exact == 1);
+ }
+
+ /* initialize */
+ if (rop != op)
+ r = rop;
+ else {
+ r = &t;
+ memset(r, '\0', sizeof(mpi));
+ }
+ memset(&quot, '\0', sizeof(mpi));
+ memset(&rem, '\0', sizeof(mpi));
+ memset(&old, '\0', sizeof(mpi));
+
+ /* root aproximation */
+ mpi_ash(r, op, -(bits - (bits / 2)));
+
+ for (;;) {
+ if (mpi_cmpabs(r, &old) == 0) {
+ exact = 0;
+ break;
+ }
+ mpi_divqr(&quot, &rem, op, r);
+ cmp = mpi_cmpabs(&quot, r);
+ if (cmp == 0) {
+ exact = mpi_cmpi(&rem, 0) == 0;
+ break;
+ }
+ else if (cmp > 0 && rem.size == 1 && rem.digs[0] == 0)
+ mpi_subi(&quot, &quot, 1);
+ mpi_set(&old, r);
+ mpi_add(r, r, &quot);
+ mpi_ash(r, r, -1);
+ }
+ mpi_clear(&quot);
+ mpi_clear(&rem);
+ mpi_clear(&old);
+ if (r != rop) {
+ mpi_set(rop, r);
+ mpi_clear(r);
+ }
+
+ return (exact);
+}
+
+void
+mpi_ash(mpi *rop, mpi *op, long shift)
+{
+ long i; /* counter */
+ long xsize; /* maximum result size */
+ BNS *digs;
+
+ /* check for 0 shift, multiply/divide by 1 */
+ if (shift == 0) {
+ if (rop != op) {
+ if (rop->alloc < op->size) {
+ rop->digs = mp_realloc(rop->digs, sizeof(BNS) * op->size);
+ rop->alloc = op->size;
+ }
+ rop->size = op->size;
+ memcpy(rop->digs, op->digs, sizeof(BNS) * op->size);
+ }
+
+ return;
+ }
+ else if (op->size == 1 && op->digs[0] == 0) {
+ rop->sign = 0;
+ rop->size = 1;
+ rop->digs[0] = 0;
+
+ return;
+ }
+
+ /* check shift and initialize */
+ if (shift > 0)
+ xsize = op->size + (shift / BNSBITS) + 1;
+ else {
+ xsize = op->size - ((-shift) / BNSBITS);
+ if (xsize <= 0) {
+ rop->size = 1;
+ rop->sign = op->sign;
+ rop->digs[0] = op->sign ? 1 : 0;
+
+ return;
+ }
+ }
+
+ /* allocate/adjust memory for result */
+ if (rop == op)
+ digs = mp_malloc(sizeof(BNS) * xsize);
+ else {
+ if (rop->alloc < xsize) {
+ rop->digs = mp_realloc(rop->digs, sizeof(BNS) * xsize);
+ rop->alloc = xsize;
+ }
+ digs = rop->digs;
+ }
+
+ /* left shift, multiply by power of two */
+ if (shift > 0)
+ rop->size = mp_lshift(digs, op->digs, op->size, shift);
+ /* right shift, divide by power of two */
+ else {
+ long carry = 0;
+
+ if (op->sign) {
+ BNI words, bits;
+
+ words = -shift / BNSBITS;
+ bits = -shift % BNSBITS;
+ for (i = 0; i < words; i++)
+ carry |= op->digs[xsize + i];
+ if (!carry) {
+ for (i = 0; i < bits; i++)
+ if (op->digs[op->size - xsize] & (1 << i)) {
+ carry = 1;
+ break;
+ }
+ }
+ }
+ rop->size = mp_rshift(digs, op->digs, op->size, -shift);
+
+ if (carry)
+ /* emulates two's complement subtracting 1 from the result */
+ rop->size = mp_add(digs, digs, mpone.digs, rop->size, 1);
+ }
+
+ if (rop->digs != digs) {
+ mp_free(rop->digs);
+ rop->alloc = rop->size;
+ rop->digs = digs;
+ }
+ rop->sign = op->sign;
+}
+
+static INLINE BNS
+mpi_logic(BNS op1, BNS op2, BNS op)
+{
+ switch (op) {
+ case '&':
+ return (op1 & op2);
+ case '|':
+ return (op1 | op2);
+ case '^':
+ return (op1 ^ op2);
+ }
+
+ return (SMASK);
+}
+
+static void
+mpi_log(mpi *rop, mpi *op1, mpi *op2, BNS op)
+{
+ long i; /* counter */
+ long c, c1, c2; /* carry */
+ BNS *digs, *digs1, *digs2; /* pointers to mp data */
+ BNI size, size1, size2;
+ BNS sign, sign1, sign2;
+ BNS n, n1, n2; /* logical operands */
+ BNI sum;
+
+ /* initialize */
+ size1 = op1->size;
+ size2 = op2->size;
+
+ sign1 = op1->sign ? SMASK : 0;
+ sign2 = op2->sign ? SMASK : 0;
+
+ sign = mpi_logic(sign1, sign2, op);
+
+ size = MAX(size1, size2);
+ if (sign)
+ ++size;
+ if (rop->alloc < size) {
+ rop->digs = mp_realloc(rop->digs, sizeof(BNS) * size);
+ rop->alloc = size;
+ }
+
+ digs = rop->digs;
+ digs1 = op1->digs;
+ digs2 = op2->digs;
+
+ c = c1 = c2 = 1;
+
+ /* apply logical operation */
+ for (i = 0; i < size; i++) {
+ if (i >= size1)
+ n1 = sign1;
+ else if (sign1) {
+ sum = (BNI)(BNS)(~digs1[i]) + c1;
+ c1 = (long)(sum >> BNSBITS);
+ n1 = (BNS)sum;
+ }
+ else
+ n1 = digs1[i];
+
+ if (i >= size2)
+ n2 = sign2;
+ else if (sign2) {
+ sum = (BNI)(BNS)(~digs2[i]) + c2;
+ c2 = (long)(sum >> BNSBITS);
+ n2 = (BNS)sum;
+ }
+ else
+ n2 = digs2[i];
+
+ n = mpi_logic(n1, n2, op);
+ if (sign) {
+ sum = (BNI)(BNS)(~n) + c;
+ c = (long)(sum >> BNSBITS);
+ digs[i] = (BNS)sum;
+ }
+ else
+ digs[i] = n;
+ }
+
+ /* normalize */
+ for (i = size - 1; i >= 0; i--)
+ if (digs[i] != 0)
+ break;
+ if (i != size - 1) {
+ if (i < 0) {
+ sign = 0;
+ size = 1;
+ }
+ else
+ size = i + 1;
+ }
+
+ rop->sign = sign != 0;
+ rop->size = size;
+}
+
+void
+mpi_and(mpi *rop, mpi *op1, mpi *op2)
+{
+ mpi_log(rop, op1, op2, '&');
+}
+
+void
+mpi_ior(mpi *rop, mpi *op1, mpi *op2)
+{
+ mpi_log(rop, op1, op2, '|');
+}
+
+void
+mpi_xor(mpi *rop, mpi *op1, mpi *op2)
+{
+ mpi_log(rop, op1, op2, '^');
+}
+
+void
+mpi_com(mpi *rop, mpi *op)
+{
+ static BNS digs[1] = { 1 };
+ static mpi one = { 0, 1, 1, (BNS*)&digs };
+
+ mpi_log(rop, rop, &one, '^');
+}
+
+void
+mpi_neg(mpi *rop, mpi *op)
+{
+ int sign = op->sign ^ 1;
+
+ if (rop->digs != op->digs) {
+ if (rop->alloc < op->size) {
+ rop->digs = mp_realloc(rop->digs, sizeof(BNS) * rop->size);
+ rop->alloc = op->size;
+ }
+ rop->size = op->size;
+ memcpy(rop->digs, op->digs, sizeof(BNS) * rop->size);
+ }
+
+ rop->sign = sign;
+}
+
+void
+mpi_abs(mpi *rop, mpi *op)
+{
+ if (rop->digs != op->digs) {
+ if (rop->alloc < op->size) {
+ rop->digs = mp_realloc(rop->digs, sizeof(BNS) * rop->size);
+ rop->alloc = op->size;
+ }
+ rop->size = op->size;
+ memcpy(rop->digs, op->digs, sizeof(BNS) * rop->size);
+ }
+
+ rop->sign = 0;
+}
+
+int
+mpi_cmp(mpi *op1, mpi *op2)
+{
+ if (op1->sign ^ op2->sign)
+ return (op1->sign ? -1 : 1);
+
+ if (op1->size == op2->size) {
+ long i, cmp = 0;
+
+ for (i = op1->size - 1; i >= 0; i--)
+ if ((cmp = (long)op1->digs[i] - (long)op2->digs[i]) != 0)
+ break;
+
+ return (cmp == 0 ? 0 : (cmp < 0) ^ op1->sign ? -1 : 1);
+ }
+
+ return ((op1->size < op2->size) ^ op1->sign ? -1 : 1);
+}
+
+int
+mpi_cmpi(mpi *op1, long op2)
+{
+ long cmp;
+
+ if (op1->size > 2)
+ return (op1->sign ? -1 : 1);
+
+ cmp = op1->digs[0];
+ if (op1->size == 2) {
+ cmp |= (long)op1->digs[1] << BNSBITS;
+ if (cmp == MINSLONG)
+ return (op2 == cmp && op1->sign ? 0 : op1->sign ? -1 : 1);
+ }
+ if (op1->sign)
+ cmp = -cmp;
+
+ return (cmp - op2);
+}
+
+int
+mpi_cmpabs(mpi *op1, mpi *op2)
+{
+ if (op1->size == op2->size) {
+ long i, cmp = 0;
+
+ for (i = op1->size - 1; i >= 0; i--)
+ if ((cmp = (long)op1->digs[i] - (long)op2->digs[i]) != 0)
+ break;
+
+ return (cmp);
+ }
+
+ return ((op1->size < op2->size) ? -1 : 1);
+}
+
+int
+mpi_cmpabsi(mpi *op1, long op2)
+{
+ unsigned long cmp;
+
+ if (op1->size > 2)
+ return (1);
+
+ cmp = op1->digs[0];
+ if (op1->size == 2)
+ cmp |= (unsigned long)op1->digs[1] << BNSBITS;
+
+ return (cmp > op2 ? 1 : cmp == op2 ? 0 : -1);
+}
+
+int
+mpi_sgn(mpi *op)
+{
+ return (op->sign ? -1 : op->size > 1 || op->digs[0] ? 1 : 0);
+}
+
+void
+mpi_swap(mpi *op1, mpi *op2)
+{
+ if (op1 != op2) {
+ mpi swap;
+
+ memcpy(&swap, op1, sizeof(mpi));
+ memcpy(op1, op2, sizeof(mpi));
+ memcpy(op2, &swap, sizeof(mpi));
+ }
+}
+
+int
+mpi_fiti(mpi *op)
+{
+ if (op->size == 1)
+ return (1);
+ else if (op->size == 2) {
+ unsigned long value = ((BNI)(op->digs[1]) << BNSBITS) | op->digs[0];
+
+ if (value & MINSLONG)
+ return (op->sign && value == MINSLONG) ? 1 : 0;
+
+ return (1);
+ }
+
+ return (0);
+}
+
+long
+mpi_geti(mpi *op)
+{
+ long value;
+
+ value = op->digs[0];
+ if (op->size > 1)
+ value |= (BNI)(op->digs[1]) << BNSBITS;
+
+ return (op->sign && value != MINSLONG ? -value : value);
+}
+
+double
+mpi_getd(mpi *op)
+{
+ long i, len;
+ double d = 0.0;
+ int exponent;
+
+#define FLOATDIGS sizeof(double) / sizeof(BNS)
+
+ switch (op->size) {
+ case 2:
+ d = (BNI)(op->digs[1]) << BNSBITS;
+ case 1:
+ d += op->digs[0];
+ return (op->sign ? -d : d);
+ default:
+ break;
+ }
+
+ for (i = 0, len = op->size; len > 0 && i < FLOATDIGS; i++)
+ d = ldexp(d, BNSBITS) + op->digs[--len];
+ d = frexp(d, &exponent);
+ if (len > 0)
+ exponent += len * BNSBITS;
+
+ if (d == 0.0)
+ return (d);
+
+ d = ldexp(d, exponent);
+
+ return (op->sign ? -d : d);
+}
+
+/* how many digits in a given base, floor(log(CARRY) / log(base)) */
+#ifdef LONG64
+static char dig_bases[37] = {
+ 0, 0, 32, 20, 16, 13, 12, 11, 10, 10, 9, 9, 8, 8, 8, 8,
+ 8, 7, 7, 7, 7, 7, 7, 7, 6, 6, 6, 6, 6, 6, 6, 6,
+ 6, 6, 6, 6, 6,
+};
+#else
+static char dig_bases[37] = {
+ 0, 0, 16, 10, 8, 6, 6, 5, 5, 5, 4, 4, 4, 4, 4, 4,
+ 4, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+ 3, 3, 3, 3, 3,
+};
+#endif
+
+/* how many digits per bit in a given base, log(2) / log(base) */
+static double bit_bases[37] = {
+ 0.0000000000000000, 0.0000000000000000, 1.0000000000000000,
+ 0.6309297535714575, 0.5000000000000000, 0.4306765580733931,
+ 0.3868528072345416, 0.3562071871080222, 0.3333333333333334,
+ 0.3154648767857287, 0.3010299956639811, 0.2890648263178878,
+ 0.2789429456511298, 0.2702381544273197, 0.2626495350371936,
+ 0.2559580248098155, 0.2500000000000000, 0.2446505421182260,
+ 0.2398124665681315, 0.2354089133666382, 0.2313782131597592,
+ 0.2276702486969530, 0.2242438242175754, 0.2210647294575037,
+ 0.2181042919855316, 0.2153382790366965, 0.2127460535533632,
+ 0.2103099178571525, 0.2080145976765095, 0.2058468324604344,
+ 0.2037950470905062, 0.2018490865820999, 0.2000000000000000,
+ 0.1982398631705605, 0.1965616322328226, 0.1949590218937863,
+ 0.1934264036172708,
+};
+
+/* normalization base for string conversion, pow(base, dig_bases[base]) & ~CARRY */
+#ifdef LONG64
+static BNS big_bases[37] = {
+ 0x00000001, 0x00000001, 0x00000000, 0xCFD41B91, 0x00000000, 0x48C27395,
+ 0x81BF1000, 0x75DB9C97, 0x40000000, 0xCFD41B91, 0x3B9ACA00, 0x8C8B6D2B,
+ 0x19A10000, 0x309F1021, 0x57F6C100, 0x98C29B81, 0x00000000, 0x18754571,
+ 0x247DBC80, 0x3547667B, 0x4C4B4000, 0x6B5A6E1D, 0x94ACE180, 0xCAF18367,
+ 0x0B640000, 0x0E8D4A51, 0x1269AE40, 0x17179149, 0x1CB91000, 0x23744899,
+ 0x2B73A840, 0x34E63B41, 0x40000000, 0x4CFA3CC1, 0x5C13D840, 0x6D91B519,
+ 0x81BF1000,
+};
+#else
+static BNS big_bases[37] = {
+ 0x0001, 0x0001, 0x0000, 0xE6A9, 0x0000, 0x3D09, 0xB640, 0x41A7, 0x8000,
+ 0xE6A9, 0x2710, 0x3931, 0x5100, 0x6F91, 0x9610, 0xC5C1, 0x0000, 0x1331,
+ 0x16C8, 0x1ACB, 0x1F40, 0x242D, 0x2998, 0x2F87, 0x3600, 0x3D09, 0x44A8,
+ 0x4CE3, 0x55C0, 0x5F45, 0x6978, 0x745F, 0x8000, 0x8C61, 0x9988, 0xA77B,
+ 0xb640,
+};
+#endif
+
+unsigned long
+mpi_getsize(mpi *op, int base)
+{
+ unsigned long value, bits;
+
+ value = op->digs[op->size - 1];
+
+ /* count leading bits */
+ if (value) {
+ unsigned long count, carry;
+
+ for (count = 0, carry = CARRY >> 1; carry; count++, carry >>= 1)
+ if (value & carry)
+ break;
+
+ bits = BNSBITS - count;
+ }
+ else
+ bits = 0;
+
+ return ((bits + (op->size - 1) * BNSBITS) * bit_bases[base] + 1);
+}
+
+char *
+mpi_getstr(char *str, mpi *op, int base)
+{
+ long i; /* counter */
+ BNS *digs, *xdigs; /* copy of op data */
+ BNI size; /* size of op */
+ BNI digits; /* digits per word in given base */
+ BNI bigbase; /* big base of given base */
+ BNI strsize; /* size of resulting string */
+ char *cp; /* pointer in str for conversion */
+
+ /* initialize */
+ size = op->size;
+ strsize = mpi_getsize(op, base) + op->sign + 1;
+
+ if (str == NULL)
+ str = mp_malloc(strsize);
+
+ /* check for zero */
+ if (size == 1 && op->digs[0] == 0) {
+ str[0] = '0';
+ str[1] = '\0';
+
+ return (str);
+ }
+
+ digits = dig_bases[base];
+ bigbase = big_bases[base];
+
+ cp = str + strsize;
+ *--cp = '\0';
+
+ /* make copy of op data and adjust digs */
+ xdigs = mp_malloc(size * sizeof(BNS));
+ memcpy(xdigs, op->digs, size * sizeof(unsigned short));
+ digs = xdigs + size - 1;
+
+ /* convert to string */
+ for (;;) {
+ long count = -1;
+ BNI value;
+ BNS quotient, remainder = 0;
+
+ /* if power of two base */
+ if ((base & (base - 1)) == 0) {
+ for (i = 0; i < size; i++) {
+ quotient = remainder;
+ remainder = digs[-i];
+ digs[-i] = quotient;
+ if (count < 0 && quotient)
+ count = i;
+ }
+ }
+ else {
+ for (i = 0; i < size; i++) {
+ value = digs[-i] + ((BNI)remainder << BNSBITS);
+ quotient = (BNS)(value / bigbase);
+ remainder = (BNS)(value % bigbase);
+ digs[-i] = quotient;
+ if (count < 0 && quotient)
+ count = i;
+ }
+ }
+ quotient = remainder;
+ for (i = 0; i < digits; i++) {
+ if (quotient == 0 && count < 0)
+ break;
+ remainder = quotient % base;
+ quotient /= base;
+ *--cp = remainder < 10 ? remainder + '0' : remainder - 10 + 'A';
+ }
+ if (count < 0)
+ break;
+ digs -= count;
+ size -= count;
+ }
+
+ /* adjust sign */
+ if (op->sign)
+ *--cp = '-';
+
+ /* remove any extra characters */
+ if (cp > str)
+ strcpy(str, cp);
+
+ mp_free(xdigs);
+
+ return (str);
+}