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Diffstat (limited to 'sysdeps/i386/fpu/fesetround.c')
-rw-r--r--sysdeps/i386/fpu/fesetround.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/sysdeps/i386/fpu/fesetround.c b/sysdeps/i386/fpu/fesetround.c
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+++ b/sysdeps/i386/fpu/fesetround.c
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+/* Set current rounding direction.
+   Copyright (C) 1997 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
+
+   The GNU C 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 GNU C 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 GNU C 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 <fenv.h>
+
+int
+fesetround (int round)
+{
+  unsigned short int cw;
+
+  if ((round & ~0xc00) != 0)
+    /* ROUND is no valid rounding mode.  */
+    return 0;
+
+  __asm__ ("fnstcw %0" : "=m" (*&cw));
+  cw &= ~0xc00;
+  cw |= round;
+  __asm__ ("fldcw %0" : : "m" (*&cw));
+
+  return 1;
+}