Initial revision

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

1 files changed, 77 insertions, 0 deletions

diff --git a/rnd_mode.c b/rnd_mode.c
new file mode 100644
index 000000000..ad48ce95c
--- /dev/null
+++ b/rnd_mode.c
@@ -0,0 +1,77 @@
+/* functions to set/get the machine rounding mode,
+   this should use the interface from the ISO C9X draft
+   (file <fenv.h>) */
+
+#include <stdio.h>
+#include "gmp.h"
+#include "mpfr.h"
+
+#ifdef IRIX64
+#include <sys/fpu.h>
+#define TOZERO swapRM(ROUND_TO_ZERO)
+#define TOINFP swapRM(ROUND_TO_PLUS_INFINITY)
+#define TONEAREST swapRM(ROUND_TO_NEAREST)
+#define TOINFM swapRM(ROUND_TO_MINUS_INFINITY)
+#elif (defined (solaris) || defined (sun4))
+#include <ieeefp.h>
+#define TOZERO fpsetround(FP_RZ)
+#define TOINFP fpsetround(FP_RP)
+#define TONEAREST fpsetround(FP_RN)
+#define TOINFM fpsetround(FP_RM)
+#elif alpha
+#ifdef __GNUC__
+/* GCC patched include files forget to define those... */
+#define FP_RND_RZ       0
+#define FP_RND_RN       1
+#define FP_RND_RP       2
+#define FP_RND_RM       3
+#endif
+#include <float.h>
+#define TOZERO write_rnd(FP_RND_RZ)
+#define TOINFP write_rnd(FP_RND_RP)
+#define TONEAREST write_rnd(FP_RND_RN)
+#define TOINFM write_rnd(FP_RND_RM)
+#elif AIX
+#include <float.h>
+#define TOZERO fp_swap_rnd(FP_RND_RZ)
+#define TOINFP fp_swap_rnd(FP_RND_RP)
+#define TONEAREST fp_swap_rnd(FP_RND_RN)
+#define TOINFM fp_swap_rnd(FP_RND_RM)
+#elif sunos
+#include <floatingpoint.h>
+char *out;
+#define TOZERO ieee_flags("set","direction","tozero",&out)
+#define TOINFP ieee_flags("set","direction","positive",&out)
+#define TONEAREST ieee_flags("set","direction","nearest",&out)
+#define TOINFM ieee_flags("set","direction","negative",&out)
+#elif hp700
+#define TOZERO fpsetround(FP_RZ)
+#define TOINFP fpsetround(FP_RP)
+#define TONEAREST fpsetround(FP_RN)
+#define TOINFM fpsetround(FP_RM)
+#elif (defined (__i386__) || defined (__i486__) || defined (linux))
+#include <fpu_control.h>
+#ifdef LIBC211
+#define __setfpucw(cw) __asm__ ("fldcw %0" : : "m" (cw))
+#endif
+/* be careful to put bits 9-8 (Precision control) 
+   to 10 (round to double precision) instead of the
+   default 11 (round to extended precision) */
+#define TOZERO __setfpucw(0x1e7f)
+#define TOINFP __setfpucw(0x1a7f)
+#define TOINFM __setfpucw(0x167f)
+#define TONEAREST __setfpucw(0x127f)
+#endif
+
+/* sets the machine rounding mode to the value rnd_mode */
+void mpfr_set_machine_rnd_mode(unsigned char rnd_mode)
+{
+  switch (rnd_mode) {
+  case GMP_RNDN: TONEAREST; break;
+  case GMP_RNDZ: TOZERO; break;
+  case GMP_RNDU: TOINFP; break;
+  case GMP_RNDD: TOINFM; break;
+  default: fprintf(stderr,"invalid rounding mode\n"); exit(1);
+  }
+}
+