Initial revision

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@2 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 46 insertions, 0 deletions

diff --git a/set_prec.c b/set_prec.c
new file mode 100644
index 000000000..a044a5344
--- /dev/null
+++ b/set_prec.c
@@ -0,0 +1,46 @@
+#include <stdio.h>
+#include "gmp.h"
+#include "gmp-impl.h"
+#include "mpfr.h"
+
+void
+#if __STDC__
+mpfr_set_prec (mpfr_t x, unsigned long int p, unsigned char rnd_mode)
+#else
+mpfr_set_prec (x, p, rnd_mode)
+     mpfr_t x;
+     unsigned long int p;
+     unsigned char rnd_mode;
+#endif
+{
+  unsigned long xsize,oldp,oldsize; mp_limb_t *old;
+
+  if (p==0) {
+    printf("*** cannot set precision to 0 bits\n"); exit(1);
+  }
+
+  oldp = x -> _mp_prec;
+  oldsize = (oldp-1)/BITS_PER_MP_LIMB + 1;
+  if (SIGN(x)<0) oldsize = oldsize ^ (1<<31);
+  xsize = (p - 1)/BITS_PER_MP_LIMB + 1; /* new limb size */
+
+  old = x -> _mp_d; 
+  x -> _mp_d = (mp_ptr) (*_mp_allocate_func) 
+    (xsize * BYTES_PER_MP_LIMB);
+  x -> _mp_prec = p;
+  mpfr_round_raw(x -> _mp_d, old, rnd_mode, oldsize, p);
+  SIZE(x) = (SIGN(x)>0) ? xsize : (xsize ^ (1<<31));
+
+  (*_mp_free_func) (old, 1 + ((oldp-1)>>3));
+}
+
+unsigned long int
+#if __STDC__
+mpfr_get_prec (mpfr_t x)
+#else
+mpfr_set_prec (x)
+     mpfr_t x;
+#endif
+{
+  return x -> _mp_prec;
+}