diff options
Diffstat (limited to 'libc/sysdeps/unix/sysv/linux/alpha/setfpucw.c')
-rw-r--r-- | libc/sysdeps/unix/sysv/linux/alpha/setfpucw.c | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/libc/sysdeps/unix/sysv/linux/alpha/setfpucw.c b/libc/sysdeps/unix/sysv/linux/alpha/setfpucw.c new file mode 100644 index 000000000..a7e3a5581 --- /dev/null +++ b/libc/sysdeps/unix/sysv/linux/alpha/setfpucw.c @@ -0,0 +1,80 @@ +/* Set FP exception mask and rounding mode. + Copyright (C) 1996, 1997, 1998, 2003 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <fpu_control.h> +#include <asm/fpu.h> + +extern void __ieee_set_fp_control (unsigned long); +libc_hidden_proto(__ieee_set_fp_control) + +extern unsigned long __ieee_get_fp_control (void); +libc_hidden_proto(__ieee_get_fp_control) + +static inline unsigned long +rdfpcr (void) +{ + unsigned long fpcr; + asm ("excb; mf_fpcr %0" : "=f"(fpcr)); + return fpcr; +} + + +static inline void +wrfpcr (unsigned long fpcr) +{ + asm volatile ("mt_fpcr %0; excb" : : "f"(fpcr)); +} + + +void +__setfpucw (fpu_control_t fpu_control) +{ + unsigned long fpcr = 0, fpcw = 0; + + if (!fpu_control) + fpu_control = _FPU_DEFAULT; + + /* first, set dynamic rounding mode: */ + + fpcr = rdfpcr(); + fpcr &= ~FPCR_DYN_MASK; + switch (fpu_control & 0xc00) + { + case _FPU_RC_NEAREST: fpcr |= FPCR_DYN_NORMAL; break; + case _FPU_RC_DOWN: fpcr |= FPCR_DYN_MINUS; break; + case _FPU_RC_UP: fpcr |= FPCR_DYN_PLUS; break; + case _FPU_RC_ZERO: fpcr |= FPCR_DYN_CHOPPED; break; + } + wrfpcr(fpcr); + + /* now tell kernel about traps that we like to hear about: */ + + fpcw = __ieee_get_fp_control(); + fpcw &= ~IEEE_TRAP_ENABLE_MASK; + + if (!(fpu_control & _FPU_MASK_IM)) fpcw |= IEEE_TRAP_ENABLE_INV; + if (!(fpu_control & _FPU_MASK_DM)) fpcw |= IEEE_TRAP_ENABLE_UNF; + if (!(fpu_control & _FPU_MASK_ZM)) fpcw |= IEEE_TRAP_ENABLE_DZE; + if (!(fpu_control & _FPU_MASK_OM)) fpcw |= IEEE_TRAP_ENABLE_OVF; + if (!(fpu_control & _FPU_MASK_PM)) fpcw |= IEEE_TRAP_ENABLE_INE; + + __fpu_control = fpu_control; /* update global copy */ + + __ieee_set_fp_control(fpcw); +} |