Imported gcc-4.4.3

[msp430-gcc.git] / gmp / mpz / ui_sub.c

diff --git a/gmp/mpz/ui_sub.c b/gmp/mpz/ui_sub.c
new file mode 100644 (file)
index 0000000..76d4b82
--- /dev/null
+++ b/gmp/mpz/ui_sub.c
@@ -0,0 +1,85 @@
+/* mpz_ui_sub -- Subtract an unsigned one-word integer and an mpz_t.
+
+Copyright 2002, 2004 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
+mpz_ui_sub (mpz_ptr w, unsigned long int uval, mpz_srcptr v)
+{
+  mp_ptr vp, wp;
+  mp_size_t vn, wn;
+  mp_limb_t cy;
+
+#if BITS_PER_ULONG > GMP_NUMB_BITS  /* avoid warnings about shift amount */
+  if (uval > GMP_NUMB_MAX)
+    {
+      mpz_t u;
+      mp_limb_t ul[2];
+      PTR(u) = ul;
+      ul[0] = uval & GMP_NUMB_MASK;
+      ul[1] = uval >> GMP_NUMB_BITS;
+      SIZ(u) = 2;
+      mpz_sub (w, u, v);
+      return;
+    }
+#endif
+
+  vp = PTR(v);
+  vn = SIZ(v);
+
+  wp = PTR(w);
+
+  if (vn > 1)
+    {
+      wp = MPZ_REALLOC (w, vn);
+      vp = PTR(v);
+      mpn_sub_1 (wp, vp, vn, (mp_limb_t) uval);
+      wn = -(vn - (wp[vn - 1] == 0));
+    }
+  else if (vn == 1)
+    {
+      if (uval >= vp[0])
+       {
+         wp[0] = uval - vp[0];
+         wn = wp[0] != 0;
+       }
+      else
+       {
+         wp[0] = vp[0] - uval;
+         wn = -1;
+       }
+    }
+  else if (vn == 0)
+    {
+      wp[0] = uval;
+      wn = uval != 0;
+    }
+  else /* (vn < 0) */
+    {
+      vn = -vn;
+      wp = MPZ_REALLOC (w, vn + 1);
+      vp = PTR(v);
+      cy = mpn_add_1 (wp, vp, vn, (mp_limb_t) uval);
+      wp[vn] = cy;
+      wn = vn + (cy != 0);
+    }
+
+  SIZ(w) = wn;
+}