Imported gcc-4.4.3

[msp430-gcc.git] / gmp / mpq / inv.c

diff --git a/gmp/mpq/inv.c b/gmp/mpq/inv.c
new file mode 100644 (file)
index 0000000..5143686
--- /dev/null
+++ b/gmp/mpq/inv.c
@@ -0,0 +1,67 @@
+/* mpq_inv(dest,src) -- invert a rational number, i.e. set DEST to SRC
+   with the numerator and denominator swapped.
+
+Copyright 1991, 1994, 1995, 2000, 2001 Free Software Foundation, Inc.
+
+This file is part of the GNU MP Library.
+
+The GNU MP Library is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 3 of the License, or (at your
+option) any later version.
+
+The GNU MP Library 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 Lesser General Public
+License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.  */
+
+#include "gmp.h"
+#include "gmp-impl.h"
+
+void
+mpq_inv (MP_RAT *dest, const MP_RAT *src)
+{
+  mp_size_t num_size = src->_mp_num._mp_size;
+  mp_size_t den_size = src->_mp_den._mp_size;
+
+  if (num_size == 0)
+    DIVIDE_BY_ZERO;
+
+  if (num_size < 0)
+    {
+      num_size = -num_size;
+      den_size = -den_size;
+    }
+  dest->_mp_den._mp_size = num_size;
+  dest->_mp_num._mp_size = den_size;
+
+  /* If dest == src we may just swap the numerator and denominator, but
+     we have to ensure the new denominator is positive.  */
+
+  if (dest == src)
+    {
+      mp_size_t alloc = dest->_mp_num._mp_alloc;
+      mp_ptr limb_ptr = dest->_mp_num._mp_d;
+
+      dest->_mp_num._mp_alloc = dest->_mp_den._mp_alloc;
+      dest->_mp_num._mp_d = dest->_mp_den._mp_d;
+
+      dest->_mp_den._mp_alloc = alloc;
+      dest->_mp_den._mp_d = limb_ptr;
+    }
+  else
+    {
+      den_size = ABS (den_size);
+      if (dest->_mp_num._mp_alloc < den_size)
+       _mpz_realloc (&(dest->_mp_num), den_size);
+
+      if (dest->_mp_den._mp_alloc < num_size)
+       _mpz_realloc (&(dest->_mp_den), num_size);
+
+      MPN_COPY (dest->_mp_num._mp_d, src->_mp_den._mp_d, den_size);
+      MPN_COPY (dest->_mp_den._mp_d, src->_mp_num._mp_d, num_size);
+    }
+}