1 files changed, 76 insertions, 0 deletions
diff --git a/mpfr/copysign.c b/mpfr/copysign.c
new file mode 100644
index 000000000..1dd88dc2f
--- /dev/null
+++ b/mpfr/copysign.c
@@ -0,0 +1,76 @@
+/* mpfr_copysign -- Produce a value with the magnitude of x and sign of y
+
+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 Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 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 Lesser General Public
+License for more details.
+
+You should have received a copy of the GNU Lesser 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 "gmp.h"
+#include "gmp-impl.h"
+#include "mpfr.h"
+#include "mpfr-impl.h"
+
+ /* The computation of z with magnitude of x and sign of y 
+
+    z = sign(y) * abs(x)
+ */
+
+int
+mpfr_copysign (mpfr_ptr z, mpfr_srcptr x ,mpfr_srcptr y , mp_rnd_t rnd_mode) 
+{
+    
+    if (MPFR_IS_NAN(y)) 
+    {  
+      MPFR_SET_NAN(z);
+      return 1; 
+    }
+
+    if (MPFR_IS_NAN(x)) 
+    {  
+      MPFR_SET_NAN(z);
+      MPFR_SET_SAME_SIGN(z,y);
+      return 1; 
+    }
+
+    MPFR_CLEAR_NAN(z);
+
+    if (MPFR_IS_INF(x)) {  
+    
+      MPFR_SET_INF(z);
+      MPFR_SET_SAME_SIGN(z,y);
+      return 0; 
+    }
+
+    MPFR_CLEAR_INF(z);
+    
+    if (!MPFR_NOTZERO(x)) 
+    {  
+      MPFR_SET_ZERO(z);
+      MPFR_SET_SAME_SIGN(z,y);      
+      return 0; 
+    }
+    
+    /* GENERAL CASE*/
+    {
+      int inexact=0;
+      inexact =mpfr_set(z,x,rnd_mode);
+      MPFR_SET_SAME_SIGN(z,y);
+      return inexact; 
+    }
+
+}