1 files changed, 61 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/alpha/setfpucw.c b/sysdeps/unix/sysv/linux/alpha/setfpucw.c
new file mode 100644
index 0000000000..5e5a352119
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/alpha/setfpucw.c
@@ -0,0 +1,61 @@
+/* Set FP exception mask and rounding mode.
+   Copyright (C) 1996-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <fpu_control.h>
+#include <fenv_libc.h>
+
+
+#define convert_bit(M, F, T)		\
+    ((T) < (F)				\
+     ? ((M) / ((F) / (T))) & (T)	\
+     : ((M) & (F)) * ((T) / (F)))
+
+
+void
+__setfpucw (fpu_control_t fpu_control)
+{
+  unsigned long fpcr, swcr, fc = (int)fpu_control;
+
+  /* ??? If this was a real external interface we'd want to read the current
+     exception state with __ieee_get_fp_control.  But this is an internal
+     function only called at process startup, so there's no point in trying
+     to preserve exceptions that cannot have been raised yet.  Indeed, this
+     entire function is likely to be one big nop unless the user overrides
+     the default __fpu_control variable.  */
+
+  /* Convert the rounding mode from fpu_control.h format.  */
+  const unsigned long conv_rnd
+    = (  (FE_TOWARDZERO << (_FPU_RC_ZERO >> 8))
+       | (FE_DOWNWARD << (_FPU_RC_DOWN >> 8))
+       | (FE_TONEAREST << (_FPU_RC_NEAREST >> 8))
+       | (FE_UPWARD << (_FPU_RC_UP >> 8)));
+
+  fpcr = ((conv_rnd >> ((fc >> 8) & 3)) & 3) << FPCR_ROUND_SHIFT;
+
+  /* Convert the exception mask from fpu_control.h format.  */
+  swcr  = convert_bit (~fc, _FPU_MASK_IM, FE_INVALID >> SWCR_ENABLE_SHIFT);
+  swcr |= convert_bit (~fc, _FPU_MASK_DM, FE_UNDERFLOW >> SWCR_ENABLE_SHIFT);
+  swcr |= convert_bit (~fc, _FPU_MASK_ZM, FE_DIVBYZERO >> SWCR_ENABLE_SHIFT);
+  swcr |= convert_bit (~fc, _FPU_MASK_OM, FE_OVERFLOW >> SWCR_ENABLE_SHIFT);
+  swcr |= convert_bit (~fc, _FPU_MASK_PM, FE_INEXACT >> SWCR_ENABLE_SHIFT);
+
+  /* Install everything.  */
+  __fpu_control = fc;
+  asm volatile ("mt_fpcr %0" : : "f"(fpcr));
+  __ieee_set_fp_control(swcr);
+}