1 /* Definitions of target machine for GNU compiler, for IBM S/390 2 Copyright (C) 1999-2013 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 #define EXPD(fp) (((fp.l.i[0]) >> 16) & 0x7FFF) 28 #define EXPONENT_BIAS 16383 29 #define MANTISSA_BITS 112 30 #define PRECISION (MANTISSA_BITS + 1) 31 #define SIGNBIT 0x80000000 32 #define SIGND(fp) ((fp.l.i[0]) & SIGNBIT) 33 #define MANTD_HIGH_LL(fp) ((fp.ll[0] & HIGH_LL_FRAC_MASK) | HIGH_LL_UNIT_BIT) 34 #define MANTD_LOW_LL(fp) (fp.ll[1]) 35 #define FRACD_ZERO_P(fp) (!fp.ll[1] && !(fp.ll[0] & HIGH_LL_FRAC_MASK)) 36 #define HIGH_LL_FRAC_BITS 48 37 #define HIGH_LL_UNIT_BIT ((UDItype_x)1 << HIGH_LL_FRAC_BITS) 38 #define HIGH_LL_FRAC_MASK (HIGH_LL_UNIT_BIT - 1) 39 40 typedef int DItype_x __attribute__ ((mode (DI))); 41 typedef unsigned int UDItype_x __attribute__ ((mode (DI))); 42 typedef int SItype_x __attribute__ ((mode (SI))); 43 typedef unsigned int USItype_x __attribute__ ((mode (SI))); 44 45 union double_long { 46 long double d; 47 struct { 48 SItype_x i[4]; /* 32 bit parts: 0 upper ... 3 lowest */ 49 } l; 50 UDItype_x ll[2]; /* 64 bit parts: 0 upper, 1 lower */ 51 }; 52 53 UDItype_x __fixunstfdi (long double a1); 54 55 /* convert double to unsigned int */ 56 UDItype_x 57 __fixunstfdi (long double a1) 58 { 59 register union double_long dl1; 60 register int exp; 61 register UDItype_x l; 62 63 dl1.d = a1; 64 65 /* +/- 0, denormalized, negative */ 66 if (!EXPD (dl1) || SIGND(dl1)) 67 return 0; 68 69 /* The exponent - considered the binary point at the right end of 70 the mantissa. */ 71 exp = EXPD (dl1) - EXPONENT_BIAS - MANTISSA_BITS; 72 73 /* number < 1: If the mantissa would need to be right-shifted more bits than 74 its size (plus the implied one bit on the left) the result would be 75 zero. */ 76 if (exp <= -PRECISION) 77 return 0; 78 79 /* NaN: All exponent bits set and a nonzero fraction. */ 80 if ((EXPD(dl1) == 0x7fff) && !FRACD_ZERO_P (dl1)) 81 return 0x0ULL; 82 83 /* One extra bit is needed for the unit bit which is appended by 84 MANTD_HIGH_LL on the left of the matissa. */ 85 exp += HIGH_LL_FRAC_BITS + 1; 86 87 /* If the result would still need a left shift it will be too large 88 to be represented. */ 89 if (exp > 0) 90 return 0xFFFFFFFFFFFFFFFFULL; 91 92 l = MANTD_LOW_LL (dl1) >> (HIGH_LL_FRAC_BITS + 1) 93 | MANTD_HIGH_LL (dl1) << (64 - (HIGH_LL_FRAC_BITS + 1)); 94 95 return l >> -exp; 96 } 97