- add C99 floating point environment, rounding and exception handling functions

  for i386. UCLIBC_HAS_FENV

1 files changed, 62 insertions, 0 deletions

diff --git a/libm/i386/fsetexcptflg.c b/libm/i386/fsetexcptflg.c
new file mode 100644
index 000000000..bdd1dcca0
--- /dev/null
+++ b/libm/i386/fsetexcptflg.c
@@ -0,0 +1,62 @@
+/* Set floating-point environment exception handling.
+   Copyright (C) 1997,99,2000,01, 2004 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 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 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <fenv.h>
+#include <math.h>
+#include <unistd.h>
+
+int
+fesetexceptflag (const fexcept_t *flagp, int excepts)
+{
+  fenv_t temp;
+
+  /* Get the current environment.  We have to do this since we cannot
+     separately set the status word.  */
+  __asm__ ("fnstenv %0" : "=m" (*&temp));
+
+  temp.__status_word &= ~(excepts & FE_ALL_EXCEPT);
+  temp.__status_word |= *flagp & excepts & FE_ALL_EXCEPT;
+
+  /* Store the new status word (along with the rest of the environment.
+     Possibly new exceptions are set but they won't get executed unless
+     the next floating-point instruction.  */
+  __asm__ ("fldenv %0" : : "m" (*&temp));
+
+#if 0
+  /* If the CPU supports SSE, we set the MXCSR as well.  */
+  if ((GLRO(dl_hwcap) & HWCAP_I386_XMM) != 0)
+    {
+      unsigned int xnew_exc;
+
+      /* Get the current MXCSR.  */
+      __asm__ ("stmxcsr %0" : "=m" (*&xnew_exc));
+
+      /* Set the relevant bits.  */
+      xnew_exc &= ~(excepts & FE_ALL_EXCEPT);
+      xnew_exc |= *flagp & excepts & FE_ALL_EXCEPT;
+
+      /* Put the new data in effect.  */
+      __asm__ ("ldmxcsr %0" : : "m" (*&xnew_exc));
+    }
+#endif
+
+  /* Success.  */
+  return 0;
+}