export isinteger in the file isinteger.c

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@1475 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 64 insertions, 0 deletions

diff --git a/isinteger.c b/isinteger.c
new file mode 100644
index 000000000..e8df80427
--- /dev/null
+++ b/isinteger.c
@@ -0,0 +1,64 @@
+/* mpfr_isinteger -- test if a mpfr variable is integer
+
+Copyright (C) 2001 Free Software Foundation.
+
+This file is part of the MPFR Library.
+
+The MPFR Library is free software; you can redistribute it and/or modify
+it under the terms of the GNU Library General Public License as published by
+the Free Software Foundation; either version 2 of the License, or (at your
+option) any later version.
+
+The MPFR 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 Library General Public
+License for more details.
+
+You should have received a copy of the GNU Library General Public License
+along with the MPFR Library; see the file COPYING.LIB.  If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+MA 02111-1307, USA. */
+
+#include <stdio.h>
+#include <math.h>
+#include "gmp.h"
+#include "gmp-impl.h"
+#include "mpfr.h"
+#include "mpfr-impl.h"
+
+ /* The computation of y=pow(x,z) is done by
+
+    y=exp(z*log(x))=x^z
+ */
+
+
+int mpfr_isinteger _PROTO((mpfr_srcptr));
+
+int 
+#if __STDC__
+mpfr_isinteger(mpfr_srcptr x)
+#else
+mpfr_isinteger(x)
+     mpfr_srcptr x;
+#endif
+{
+
+  mpfr_t u;
+  int expo;
+  mp_prec_t prec;
+
+  expo=(int)MPFR_EXP(x);
+  prec=MPFR_PREC(x);
+
+  if (expo<=0) 
+    return 0;
+
+  if (expo>=prec) 
+    return 1;
+
+  mpfr_init2(u,prec);
+  mpfr_trunc(u,x);
+
+  if(mpfr_cmp(x,u)==0) return 1;
+  else return 0;
+}