1 /* Definitions of target machine for GNU compiler, for IBM S/390 2 Copyright (C) 1999, 2000, 2001, 2007, 2008 and 2009 3 Free Software Foundation, Inc. 4 Contributed by Hartmut Penner (hpenner@de.ibm.com) and 5 Ulrich Weigand (uweigand@de.ibm.com). 6 7 This file is part of GCC. 8 9 GCC is free software; you can redistribute it and/or modify it under 10 the terms of the GNU General Public License as published by the Free 11 Software Foundation; either version 3, or (at your option) any later 12 version. 13 14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 15 WARRANTY; without even the implied warranty of MERCHANTABILITY or 16 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 17 for more details. 18 19 Under Section 7 of GPL version 3, you are granted additional 20 permissions described in the GCC Runtime Library Exception, version 21 3.1, as published by the Free Software Foundation. 22 23 You should have received a copy of the GNU General Public License and 24 a copy of the GCC Runtime Library Exception along with this program; 25 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 26 <http://www.gnu.org/licenses/>. */ 27 28 #define EXPD(fp) (((fp.l.i[0]) >> 16) & 0x7FFF) 29 #define EXPONENT_BIAS 16383 30 #define MANTISSA_BITS 112 31 #define PRECISION (MANTISSA_BITS + 1) 32 #define SIGNBIT 0x80000000 33 #define SIGND(fp) ((fp.l.i[0]) & SIGNBIT) 34 #define MANTD_HIGH_LL(fp) ((fp.ll[0] & HIGH_LL_FRAC_MASK) | HIGH_LL_UNIT_BIT) 35 #define MANTD_LOW_LL(fp) (fp.ll[1]) 36 #define FRACD_ZERO_P(fp) (!fp.ll[1] && !(fp.ll[0] & HIGH_LL_FRAC_MASK)) 37 #define HIGH_LL_FRAC_BITS 48 38 #define HIGH_LL_UNIT_BIT ((UDItype_x)1 << HIGH_LL_FRAC_BITS) 39 #define HIGH_LL_FRAC_MASK (HIGH_LL_UNIT_BIT - 1) 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 double_long { 47 long double d; 48 struct { 49 SItype_x i[4]; /* 32 bit parts: 0 upper ... 3 lowest */ 50 } l; 51 UDItype_x ll[2]; /* 64 bit parts: 0 upper, 1 lower */ 52 }; 53 54 UDItype_x __fixunstfdi (long double a1); 55 56 /* convert double to unsigned int */ 57 UDItype_x 58 __fixunstfdi (long double a1) 59 { 60 register union double_long dl1; 61 register int exp; 62 register UDItype_x l; 63 64 dl1.d = a1; 65 66 /* +/- 0, denormalized, negative */ 67 if (!EXPD (dl1) || SIGND(dl1)) 68 return 0; 69 70 /* The exponent - considered the binary point at the right end of 71 the mantissa. */ 72 exp = EXPD (dl1) - EXPONENT_BIAS - MANTISSA_BITS; 73 74 /* number < 1: If the mantissa would need to be right-shifted more bits than 75 its size (plus the implied one bit on the left) the result would be 76 zero. */ 77 if (exp <= -PRECISION) 78 return 0; 79 80 /* NaN: All exponent bits set and a nonzero fraction. */ 81 if ((EXPD(dl1) == 0x7fff) && !FRACD_ZERO_P (dl1)) 82 return 0x0ULL; 83 84 /* One extra bit is needed for the unit bit which is appended by 85 MANTD_HIGH_LL on the left of the matissa. */ 86 exp += HIGH_LL_FRAC_BITS + 1; 87 88 /* If the result would still need a left shift it will be too large 89 to be represented. */ 90 if (exp > 0) 91 return 0xFFFFFFFFFFFFFFFFULL; 92 93 l = MANTD_LOW_LL (dl1) >> (HIGH_LL_FRAC_BITS + 1) 94 | MANTD_HIGH_LL (dl1) << (64 - (HIGH_LL_FRAC_BITS + 1)); 95 96 return l >> -exp; 97 } 98