sysdeps/unix/sysv/linux/alpha/fraiseexcpt.c

   1 /* Copyright (C) 2004,2006 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <fenv_libc.h>
  20 #include <sysdep.h>
  21 #include <float.h>
  22 #include <kernel-features.h>
  23 #include "kernel_sysinfo.h"
  24
  25
  26 int
  27 __feraiseexcept (int excepts)
  28 {
  29   INTERNAL_SYSCALL_DECL (err);
  30   unsigned long t = excepts;
  31   long r;
  32
  33   r = INTERNAL_SYSCALL (osf_setsysinfo, err, 2, SSI_IEEE_RAISE_EXCEPTION, &t);
  34
  35 #ifndef __ASSUME_IEEE_RAISE_EXCEPTION
  36   if (!INTERNAL_SYSCALL_ERROR_P (r, err))
  37     return 0;
  38
  39   double d;
  40
  41   /* If we got an error from SSI_IEEE_RAISE_EXCEPTION, assume it means that
  42      the system call isn't actually implemented.  Do the best we can.  */
  43
  44   /* Invalid implemented with 0 / 0 -> NaN.  */
  45   if (excepts & FE_INVALID)
  46     __asm__ __volatile__ ("divs/su $f31,$f31,%0; trapb" : "=f"(d) : );
  47
  48   /* Division By Zero implemented with 1 / 0 -> NaN.  */
  49   if (excepts & FE_DIVBYZERO)
  50     __asm__ __volatile__ ("divs/su %1,$f31,%0; trapb" : "=&f"(d) : "f"(1.0f));
  51
  52   /* Overflow and underflow cannot be had all by themselves.  We can
  53      generate them with arithmetic, but we always get INEXACT raised
  54      at the same time.  Prepare to undo.  */
  55   if ((excepts & (FE_OVERFLOW | FE_UNDERFLOW)) && !(excepts & FE_INEXACT))
  56     INTERNAL_SYSCALL (osf_getsysinfo, err, 2, GSI_IEEE_FP_CONTROL, &t);
  57
  58   /* Overflow implemented with FLT_MAX + FLT_MAX -> Inf.  */
  59   if (excepts & FE_OVERFLOW)
  60     __asm__ __volatile__ ("adds/sui %1,%1,%0; trapb"
  61                           : "=&f"(d) : "f"(FLT_MAX));
  62
  63   /* Underflow implemented with FLT_MIN * FLT_MIN -> 0.  */
  64   if (excepts & FE_UNDERFLOW)
  65     __asm__ __volatile__ ("muls/sui %1,%1,%0; trapb"
  66                           : "=&f"(d) : "f"(FLT_MIN));
  67
  68   /* Inexact implemented with (long)0.5 -> 0.  */
  69   if ((excepts & (FE_OVERFLOW | FE_UNDERFLOW | FE_INEXACT)) == FE_INEXACT)
  70     __asm__ __volatile__ ("cvttq/svi %1,%0; trapb" : "=&f"(d) : "f"(0.5f));
  71
  72   /* If we raised inexact when not asked, and inexact was not previously
  73      raised, then clear that exception.  */
  74   if ((excepts & (FE_OVERFLOW | FE_UNDERFLOW))
  75       && !((excepts | t) & FE_INEXACT))
  76     {
  77       t |= excepts & SWCR_STATUS_MASK;
  78       INTERNAL_SYSCALL (osf_setsysinfo, err, 2, SSI_IEEE_FP_CONTROL, &t);
  79     }
  80 #endif /* !__ASSUME_IEEE_RAISE_EXCEPTION */
  81
  82   return 0;
  83 }
  84
  85 #include <shlib-compat.h>
  86 #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
  87 strong_alias (__feraiseexcept, __old_feraiseexcept)
  88 compat_symbol (libm, __old_feraiseexcept, feraiseexcept, GLIBC_2_1);
  89 #endif
  90
  91 libm_hidden_ver (__feraiseexcept, feraiseexcept)
  92 versioned_symbol (libm, __feraiseexcept, feraiseexcept, GLIBC_2_2);