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Diffstat (limited to 'sysdeps/alpha/fpu/fesetenv.c')
-rw-r--r--sysdeps/alpha/fpu/fesetenv.c45
1 files changed, 45 insertions, 0 deletions
diff --git a/sysdeps/alpha/fpu/fesetenv.c b/sysdeps/alpha/fpu/fesetenv.c
new file mode 100644
index 0000000000..3692967a5b
--- /dev/null
+++ b/sysdeps/alpha/fpu/fesetenv.c
@@ -0,0 +1,45 @@
+/* Install given floating-point environment.
+ Copyright (C) 1997 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Richard Henderson <rth@tamu.edu>, 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>
+
+void
+fesetenv (const fenv_t *envp)
+{
+ unsigned long fpcr;
+ fenv_t env;
+
+ /* Magic encoding of default values: high bit set (never possible for a
+ user-space address) is not indirect. And we don't even have to get
+ rid of it since we mask things around just below. */
+ if ((long)envp >= 0)
+ env = *envp;
+ else
+ env = (unsigned long)envp;
+
+ /* Reset the rounding mode with the hardware fpcr. Note that the following
+ system call is an implied trap barrier for our modification. */
+ __asm__ __volatile__("excb; mf_fpcr %0" : "=f"(fpcr));
+ fpcr = (fpcr & ~(3UL << 58)) | (env & (3UL << 58));
+ __asm__ __volatile__("mt_fpcr %0" : : "f"(fpcr));
+
+ /* Reset the exception status and mask with the kernel's FP code. */
+ __ieee_set_fp_control(env & (FE_ALL_EXCEPT | 0x3e));
+}