sysdeps/hppa/fpu/fraiseexcpt.c

   1 /* Raise given exceptions.
   2    Copyright (C) 1997-2024 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library.  If not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <fenv.h>
  20 #include <float.h>
  21 #include <math.h>
  22
  23 /* Please see section 10,
  24    page 10-5 "Delayed Trapping" in the PA-RISC 2.0 Architecture manual */
  25
  26 int
  27 __feraiseexcept (int excepts)
  28 {
  29   /* Raise exceptions represented by EXCEPTS.  But we must raise only one
  30      signal at a time.  It is important that if the overflow/underflow
  31      exception and the divide by zero exception are given at the same
  32      time, the overflow/underflow exception follows the divide by zero
  33      exception.  */
  34
  35   /* We do these bits in assembly to be certain GCC doesn't optimize
  36      away something important, and so we can force delayed traps to
  37      occur. */
  38
  39   /* We use "fldd 0(%%sr0,%%sp),%0" to flush the delayed exception */
  40
  41   /* First: Invalid exception.  */
  42   if (excepts & FE_INVALID)
  43     {
  44       /* One example of an invalid operation is 0 * Infinity.  */
  45       double d = HUGE_VAL;
  46       __asm__ __volatile__ (
  47                 "       fcpy,dbl %%fr0,%%fr22\n"
  48                 "       fmpy,dbl %0,%%fr22,%0\n"
  49                 "       fldd 0(%%sr0,%%sp),%0"
  50                 : "+f" (d) : : "%fr22" );
  51     }
  52
  53   /* Second: Division by zero.  */
  54   if (excepts & FE_DIVBYZERO)
  55     {
  56       double d = 1.0;
  57       __asm__ __volatile__ (
  58                 "       fcpy,dbl %%fr0,%%fr22\n"
  59                 "       fdiv,dbl %0,%%fr22,%0\n"
  60                 "       fldd 0(%%sr0,%%sp),%0"
  61                 : "+f" (d) : : "%fr22" );
  62     }
  63
  64   /* Third: Overflow.  */
  65   if (excepts & FE_OVERFLOW)
  66     {
  67       double d = DBL_MAX;
  68       __asm__ __volatile__ (
  69                 "       fadd,dbl %0,%0,%0\n"
  70                 "       fldd 0(%%sr0,%%sp),%0"
  71                 : "+f" (d) );
  72     }
  73
  74   /* Fourth: Underflow.  */
  75   if (excepts & FE_UNDERFLOW)
  76     {
  77       double d = DBL_MIN;
  78       double e = 3.0;
  79       __asm__ __volatile__ (
  80                 "       fdiv,dbl %0,%1,%0\n"
  81                 "       fldd 0(%%sr0,%%sp),%0"
  82                 : "+f" (d) : "f" (e) );
  83     }
  84
  85   /* Fifth: Inexact */
  86   if (excepts & FE_INEXACT)
  87     {
  88       double d = M_PI;
  89       double e = 69.69;
  90       __asm__ __volatile__ (
  91                 "       fdiv,dbl %0,%1,%%fr22\n"
  92                 "       fcnvfxt,dbl,sgl %%fr22,%%fr22L\n"
  93                 "       fldd 0(%%sr0,%%sp),%%fr22"
  94                 : : "f" (d), "f" (e) : "%fr22" );
  95     }
  96
  97   /* Success.  */
  98   return 0;
  99 }
 100 libm_hidden_def (__feraiseexcept)
 101 weak_alias (__feraiseexcept, feraiseexcept)
 102 libm_hidden_weak (feraiseexcept)