libgcc/config/s390/32/_fixsfdi.c

   1 /* Definitions of target machine for GNU compiler, for IBM S/390
   2    Copyright (C) 1999-2024 Free Software Foundation, Inc.
   3    Contributed by Hartmut Penner (hpenner@de.ibm.com) and
   4                   Ulrich Weigand (uweigand@de.ibm.com).
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 Under Section 7 of GPL version 3, you are granted additional
  19 permissions described in the GCC Runtime Library Exception, version
  20 3.1, as published by the Free Software Foundation.
  21
  22 You should have received a copy of the GNU General Public License and
  23 a copy of the GCC Runtime Library Exception along with this program;
  24 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  25 <http://www.gnu.org/licenses/>.  */
  26
  27 #ifndef __s390x__
  28
  29 #define EXPONENT_BIAS   127
  30 #define MANTISSA_BITS   23
  31 #define EXP(fp)         (((fp.l) >> MANTISSA_BITS) & 0xFF)
  32 #define PRECISION       (MANTISSA_BITS + 1)
  33 #define SIGNBIT         0x80000000
  34 #define SIGN(fp)        ((fp.l) & SIGNBIT)
  35 #define HIDDEN          (1 << MANTISSA_BITS)
  36 #define MANT(fp)        (((fp.l) & 0x7FFFFF) | HIDDEN)
  37 #define FRAC(fp)        ((fp.l) & 0x7FFFFF)
  38 #define LLONG_MAX       9223372036854775807LL
  39 #define LLONG_MIN       (-LLONG_MAX - 1LL)
  40
  41 typedef int DItype_x __attribute__ ((mode (DI)));
  42 typedef unsigned int UDItype_x __attribute__ ((mode (DI)));
  43 typedef int SItype_x __attribute__ ((mode (SI)));
  44 typedef unsigned int USItype_x __attribute__ ((mode (SI)));
  45
  46 union float_long
  47   {
  48     float f;
  49     USItype_x l;
  50   };
  51
  52 static __inline__ void
  53 fexceptdiv (float d, float e)
  54 {
  55   __asm__ __volatile__ ("debr %0,%1" : : "f" (d), "f" (e) );
  56 }
  57
  58 DItype_x __fixsfdi (float a1);
  59
  60 /* convert double to int */
  61 DItype_x
  62 __fixsfdi (float a1)
  63 {
  64     register union float_long fl1;
  65     register int exp;
  66     register DItype_x l;
  67
  68     fl1.f = a1;
  69
  70     /* +/- 0, denormalized */
  71     if (!EXP (fl1))
  72       return 0;
  73
  74     exp = EXP (fl1) - EXPONENT_BIAS - MANTISSA_BITS;
  75
  76     /* number < 1 */
  77     if (exp <= -PRECISION)
  78       return 0;
  79
  80     /* NaN */
  81
  82     if ((EXP (fl1) == 0xff) && (FRAC (fl1) != 0)) /* NaN */
  83       {
  84         /* C99 Annex F.4 requires an "invalid" exception to be thrown.  */
  85         fexceptdiv (0.0, 0.0);
  86         return 0x8000000000000000ULL;
  87       }
  88
  89     /* Number big number & +/- inf */
  90     if (exp >= 40) {
  91       /* Don't throw an exception for -1p+63  */
  92       if (!SIGN (fl1) || exp > 40 || FRAC (fl1) != 0)
  93         /* C99 Annex F.4 requires an "invalid" exception to be thrown.  */
  94         fexceptdiv (0.0, 0.0);
  95       return SIGN (fl1) ? LLONG_MIN : LLONG_MAX;
  96     }
  97
  98     l = MANT (fl1);
  99
 100     if (exp > 0)
 101       l <<= exp;
 102     else
 103       l >>= -exp;
 104
 105     return (SIGN (fl1) ? -l : l);
 106 }
 107 #endif /* !__s390x__ */