1 /* Definitions of target machine for GNU compiler, for IBM S/390
2 Copyright (C) 1999-2023 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 EXPD(fp) (((fp.l.i[0]) >> 16) & 0x7FFF)
30 #define EXPONENT_BIAS 16383
31 #define MANTISSA_BITS 112
32 #define PRECISION (MANTISSA_BITS + 1)
33 #define SIGNBIT 0x80000000
34 #define SIGND(fp) ((fp.l.i[0]) & SIGNBIT)
35 #define MANTD_HIGH_LL(fp) ((fp.ll[0] & HIGH_LL_FRAC_MASK) | HIGH_LL_UNIT_BIT)
36 #define MANTD_LOW_LL(fp) (fp.ll[1])
37 #define FRACD_ZERO_P(fp) (!fp.ll[1] && !(fp.ll[0] & HIGH_LL_FRAC_MASK))
38 #define HIGH_LL_FRAC_BITS 48
39 #define HIGH_LL_UNIT_BIT ((UDItype_x)1 << HIGH_LL_FRAC_BITS)
40 #define HIGH_LL_FRAC_MASK (HIGH_LL_UNIT_BIT - 1)
41
42 typedef int DItype_x __attribute__ ((mode (DI)));
43 typedef unsigned int UDItype_x __attribute__ ((mode (DI)));
44 typedef int SItype_x __attribute__ ((mode (SI)));
45 typedef unsigned int USItype_x __attribute__ ((mode (SI)));
46
47 union double_long {
48 long double d;
49 struct {
50 SItype_x i[4]; /* 32 bit parts: 0 upper ... 3 lowest */
51 } l;
52 UDItype_x ll[2]; /* 64 bit parts: 0 upper, 1 lower */
53 };
54
55 static __inline__ void
56 fexceptdiv (float d, float e)
57 {
58 __asm__ __volatile__ ("debr %0,%1" : : "f" (d), "f" (e) );
59 }
60
61 UDItype_x __fixunstfdi (long double a1);
62
63 /* convert double to unsigned int */
64 UDItype_x
65 __fixunstfdi (long double a1)
66 {
67 register union double_long dl1;
68 register int exp;
69 register UDItype_x l;
70
71 dl1.d = a1;
72
73 /* +/- 0, denormalized */
74 if (!EXPD (dl1))
75 return 0;
76
77 /* Negative. */
78 if (SIGND (dl1))
79 {
80 /* Value is <= -1.0
81 C99 Annex F.4 requires an "invalid" exception to be thrown. */
82 if (EXPD (dl1) >= EXPONENT_BIAS)
83 fexceptdiv (0.0, 0.0);
84 return 0;
85 }
86
87 /* The exponent - considered the binary point at the right end of
88 the mantissa. */
89 exp = EXPD (dl1) - EXPONENT_BIAS - MANTISSA_BITS;
90
91 /* number < 1: If the mantissa would need to be right-shifted more bits than
92 its size (plus the implied one bit on the left) the result would be
93 zero. */
94 if (exp <= -PRECISION)
95 return 0;
96
97 /* NaN: All exponent bits set and a nonzero fraction. */
98 if ((EXPD(dl1) == 0x7fff) && !FRACD_ZERO_P (dl1))
99 {
100 /* C99 Annex F.4 requires an "invalid" exception to be thrown. */
101 fexceptdiv (0.0, 0.0);
102 return 0;
103 }
104
105 /* One extra bit is needed for the unit bit which is appended by
106 MANTD_HIGH_LL on the left of the matissa. */
107 exp += HIGH_LL_FRAC_BITS + 1;
108
109 /* If the result would still need a left shift it will be too
110 large to be represented. Infinities have all exponent bits set
111 and will end up here as well. */
112 if (exp > 0)
113 {
114 /* C99 Annex F.4 requires an "invalid" exception to be thrown. */
115 fexceptdiv (0.0, 0.0);
116 return 0xFFFFFFFFFFFFFFFFULL;
117 }
118
119 l = MANTD_LOW_LL (dl1) >> (HIGH_LL_FRAC_BITS + 1)
120 | MANTD_HIGH_LL (dl1) << (64 - (HIGH_LL_FRAC_BITS + 1));
121
122 return l >> -exp;
123 }
124
125 #endif /* !__s390x__ */