Imported gcc-4.4.3

[msp430-gcc.git] / gmp / mpz / cfdiv_q_2exp.c

diff --git a/gmp/mpz/cfdiv_q_2exp.c b/gmp/mpz/cfdiv_q_2exp.c
new file mode 100644 (file)
index 0000000..a54ce2d
--- /dev/null
+++ b/gmp/mpz/cfdiv_q_2exp.c
@@ -0,0 +1,102 @@
+/* mpz_cdiv_q_2exp, mpz_fdiv_q_2exp -- quotient from mpz divided by 2^n.
+
+Copyright 1991, 1993, 1994, 1996, 1998, 1999, 2001, 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"
+
+
+/* dir==1 for ceil, dir==-1 for floor */
+
+static void __gmpz_cfdiv_q_2exp __GMP_PROTO ((REGPARM_3_1 (mpz_ptr w, mpz_srcptr u, unsigned long cnt, int dir))) REGPARM_ATTR (1);
+#define cfdiv_q_2exp(w,u,cnt,dir)  __gmpz_cfdiv_q_2exp (REGPARM_3_1 (w,u,cnt,dir))
+
+REGPARM_ATTR (1) static void
+cfdiv_q_2exp (mpz_ptr w, mpz_srcptr u, unsigned long cnt, int dir)
+{
+  mp_size_t  wsize, usize, abs_usize, limb_cnt, i;
+  mp_srcptr  up;
+  mp_ptr     wp;
+  mp_limb_t  round, rmask;
+
+  usize = SIZ (u);
+  abs_usize = ABS (usize);
+  limb_cnt = cnt / GMP_NUMB_BITS;
+  wsize = abs_usize - limb_cnt;
+  if (wsize <= 0)
+    {
+      /* u < 2**cnt, so result 1, 0 or -1 according to rounding */
+      PTR(w)[0] = 1;
+      SIZ(w) = (usize == 0 || (usize ^ dir) < 0 ? 0 : dir);
+      return;
+    }
+
+  /* +1 limb to allow for mpn_add_1 below */
+  MPZ_REALLOC (w, wsize+1);
+
+  /* Check for rounding if direction matches u sign.
+     Set round if we're skipping non-zero limbs.  */
+  up = PTR(u);
+  round = 0;
+  rmask = ((usize ^ dir) >= 0 ? MP_LIMB_T_MAX : 0);
+  if (rmask != 0)
+    for (i = 0; i < limb_cnt && round == 0; i++)
+      round = up[i];
+
+  wp = PTR(w);
+  cnt %= GMP_NUMB_BITS;
+  if (cnt != 0)
+    {
+      round |= rmask & mpn_rshift (wp, up + limb_cnt, wsize, cnt);
+      wsize -= (wp[wsize - 1] == 0);
+    }
+  else
+    MPN_COPY_INCR (wp, up + limb_cnt, wsize);
+
+  if (round != 0)
+    {
+      if (wsize != 0)
+       {
+          mp_limb_t cy;
+         cy = mpn_add_1 (wp, wp, wsize, CNST_LIMB(1));
+         wp[wsize] = cy;
+         wsize += cy;
+       }
+      else
+       {
+         /* We shifted something to zero.  */
+         wp[0] = 1;
+         wsize = 1;
+       }
+    }
+  SIZ(w) = (usize >= 0 ? wsize : -wsize);
+}
+
+
+void
+mpz_cdiv_q_2exp (mpz_ptr w, mpz_srcptr u, unsigned long cnt)
+{
+  cfdiv_q_2exp (w, u, cnt, 1);
+}
+
+void
+mpz_fdiv_q_2exp (mpz_ptr w, mpz_srcptr u, unsigned long cnt)
+{
+  cfdiv_q_2exp (w, u, cnt, -1);
+}