1 files changed, 45 insertions, 41 deletions
diff --git a/src/mp.c b/src/mp.c
index 0037135..3003202 100644
--- a/src/mp.c
+++ b/src/mp.c
@@ -1,20 +1,12 @@
-/* Copyright (c) 1987-2008 Sun Microsystems, Inc. All Rights Reserved.
- * Copyright (c) 2008-2009 Robert Ancell
+/*
+ * Copyright (C) 1987-2008 Sun Microsystems, Inc. All Rights Reserved.
+ * Copyright (C) 2008-2011 Robert Ancell
 *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
- * 02110-1301, USA.
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, either version 2 of the License, or (at your option) any later
+ * version. See http://www.gnu.org/copyleft/gpl.html the full text of the
+ * license.
 */
 
 #include <stdlib.h>
@@ -25,6 +17,9 @@
 #include "mp.h"
 #include "mp-private.h"
 
+static MPNumber eulers_number;
+static gboolean have_eulers_number = FALSE;
+
 // FIXME: Re-add overflow and underflow detection
 
 char *mp_error = NULL;
@@ -101,9 +96,13 @@ mp_ext(int i, int j, MPNumber *x)
 void
 mp_get_eulers(MPNumber *z)
 {
- MPNumber t;
- mp_set_from_integer(1, &t);
- mp_epowy(&t, z);
+ if (!have_eulers_number) {
+ MPNumber t;
+ mp_set_from_integer(1, &t);
+ mp_epowy(&t, &eulers_number);
+ have_eulers_number = TRUE;
+ }
+ mp_set_from_mp(&eulers_number, z);
 }
 
 
@@ -212,8 +211,8 @@ mp_imaginary_component(const MPNumber *x, MPNumber *z)
 z->sign = x->im_sign;
 z->exponent = x->im_exponent;
 memcpy(z->fraction, x->im_fraction, sizeof(int) * MP_SIZE);
-
- /* Clear (old) imaginary component */
+ 
+ /* Clear (old) imaginary component */ 
 z->im_sign = 0;
 z->im_exponent = 0;
 memset(z->im_fraction, 0, sizeof(int) * MP_SIZE);
@@ -235,7 +234,7 @@ mp_add_real(const MPNumber *x, int y_sign, const MPNumber *y, MPNumber *z)
 z->sign = y_sign;
 return;
 }
- /* x + 0 = x */
+ /* x + 0 = x */ 
 else if (mp_is_zero(y)) {
 mp_set_from_mp(x, z);
 return;
@@ -293,6 +292,15 @@ mp_add_real(const MPNumber *x, int y_sign, const MPNumber *y, MPNumber *z)
 z->fraction[MP_T + i] = 0;
 
 if (sign_prod >= 0) {
+ /* This is probably insufficient overflow detection, but it makes us
+ * not crash at least.
+ */
+ if (MP_T + 3 < med) {
+ mperr(_("Overflow: the result couldn't be calculated"));
+ mp_set_from_integer(0, z);
+ return;
+ }
+
 /* HERE DO ADDITION, EXPONENT(Y) >= EXPONENT(X) */
 for (i = MP_T + 3; i >= MP_T; i--)
 z->fraction[i] = small_fraction[i - med];
@@ -450,7 +458,7 @@ mp_sgn(const MPNumber *x, MPNumber *z)
 else if (mp_is_negative(x))
 mp_set_from_integer(-1, z);
 else
- mp_set_from_integer(1, z);
+ mp_set_from_integer(1, z); 
 }
 
 void
@@ -829,7 +837,7 @@ bool
 mp_is_integer(const MPNumber *x)
 {
 MPNumber t1, t2, t3;
-
+ 
 if (mp_is_complex(x))
 return false;
 
@@ -978,7 +986,7 @@ mp_epowy_real(const MPNumber *x, MPNumber *z)
 {
 float r__1;
 int i, ix, xs, tss;
- float rx, rz, rlb;
+ float rx, rz;
 MPNumber t1, t2;
 
 /* e^0 = 1 */
@@ -993,11 +1001,6 @@ mp_epowy_real(const MPNumber *x, MPNumber *z)
 return;
 }
 
- /* SEE IF ABS(X) SO LARGE THAT EXP(X) WILL CERTAINLY OVERFLOW
- * OR UNDERFLOW. 1.01 IS TO ALLOW FOR ERRORS IN ALOG.
- */
- rlb = log((float)MP_BASE) * 1.01f;
-
 /* NOW SAFE TO CONVERT X TO REAL */
 rx = mp_cast_to_float(x);
 
@@ -1303,7 +1306,7 @@ void
 mp_logarithm(int64_t n, const MPNumber *x, MPNumber *z)
 {
 MPNumber t1, t2;
-
+ 
 /* log(0) undefined */
 if (mp_is_zero(x)) {
 /* Translators: Error displayed when attempting to take logarithm of zero */
@@ -1333,7 +1336,7 @@ mp_multiply_real(const MPNumber *x, const MPNumber *y, MPNumber *z)
 int c, i, xi;
 MPNumber r;
 
- /* x*0 = 0*y = 0 */
+ /* x*0 = 0*y = 0 */ 
 if (x->sign == 0 || y->sign == 0) {
 mp_set_from_integer(0, z);
 return;
@@ -1418,7 +1421,7 @@ mp_multiply_real(const MPNumber *x, const MPNumber *y, MPNumber *z)
 /* Clear complex part */
 z->im_sign = 0;
 z->im_exponent = 0;
- memset(z->im_fraction, 0, sizeof(int) * MP_SIZE);
+ memset(z->im_fraction, 0, sizeof(int) * MP_SIZE); 
 
 /* NORMALIZE AND ROUND RESULT */
 // FIXME: Use stack variable because of mp_normalize brokeness
@@ -1445,11 +1448,11 @@ mp_multiply(const MPNumber *x, const MPNumber *y, MPNumber *z)
 mp_imaginary_component(x, &im_x);
 mp_real_component(y, &real_y);
 mp_imaginary_component(y, &im_y);
-
+ 
 mp_multiply_real(&real_x, &real_y, &t1);
 mp_multiply_real(&im_x, &im_y, &t2);
 mp_subtract(&t1, &t2, &real_z);
-
+ 
 mp_multiply_real(&real_x, &im_y, &t1);
 mp_multiply_real(&im_x, &real_y, &t2);
 mp_add(&t1, &t2, &im_z);
@@ -1574,7 +1577,7 @@ mp_multiply_integer_real(const MPNumber *x, int64_t y, MPNumber *z)
 
 z->im_sign = 0;
 z->im_exponent = 0;
- memset(z->im_fraction, 0, sizeof(int) * MP_SIZE);
+ memset(z->im_fraction, 0, sizeof(int) * MP_SIZE); 
 mp_normalize(z);
 }
 
@@ -1670,10 +1673,11 @@ mp_pwr(const MPNumber *x, const MPNumber *y, MPNumber *z)
 return;
 }*/
 
- /* 0^-y illegal */
- if (mp_is_zero(x) && y->sign < 0) {
- mperr(_("The power of zero is undefined for a negative exponent"));
+ /* 0^y = 0, 0^-y undefined */ 
+ if (mp_is_zero(x)) {
 mp_set_from_integer(0, z);
+ if (y->sign < 0)
+ mperr(_("The power of zero is undefined for a negative exponent"));
 return;
 }
 
@@ -1746,7 +1750,7 @@ mp_reciprocal_real(const MPNumber *x, MPNumber *z)
 
 void
 mp_reciprocal(const MPNumber *x, MPNumber *z)
-{
+{ 
 if (mp_is_complex(x)) {
 MPNumber t1, t2;
 MPNumber real_x, im_x;
@@ -2003,7 +2007,7 @@ mp_xpowy_integer(const MPNumber *x, int64_t n, MPNumber *z)
 mp_set_from_integer(0, z);
 return;
 }
-
+ 
 /* x^1 = x */
 if (n == 1) {
 mp_set_from_mp(x, z);