URL
https://opencores.org/ocsvn/openrisc_me/openrisc_me/trunk
Subversion Repositories openrisc_me
[/] [openrisc/] [trunk/] [gnu-src/] [gcc-4.5.1/] [libgcc/] [config/] [s390/] [32/] [_fixunstfdi.c] - Rev 298
Go to most recent revision | Compare with Previous | Blame | View Log
/* Definitions of target machine for GNU compiler, for IBM S/390 Copyright (C) 1999, 2000, 2001, 2007, 2008 and 2009 Free Software Foundation, Inc. Contributed by Hartmut Penner (hpenner@de.ibm.com) and Ulrich Weigand (uweigand@de.ibm.com). This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. Under Section 7 of GPL version 3, you are granted additional permissions described in the GCC Runtime Library Exception, version 3.1, as published by the Free Software Foundation. You should have received a copy of the GNU General Public License and a copy of the GCC Runtime Library Exception along with this program; see the files COPYING3 and COPYING.RUNTIME respectively. If not, see <http://www.gnu.org/licenses/>. */ #define EXPD(fp) (((fp.l.i[0]) >> 16) & 0x7FFF) #define EXPONENT_BIAS 16383 #define MANTISSA_BITS 112 #define PRECISION (MANTISSA_BITS + 1) #define SIGNBIT 0x80000000 #define SIGND(fp) ((fp.l.i[0]) & SIGNBIT) #define MANTD_HIGH_LL(fp) ((fp.ll[0] & HIGH_LL_FRAC_MASK) | HIGH_LL_UNIT_BIT) #define MANTD_LOW_LL(fp) (fp.ll[1]) #define FRACD_ZERO_P(fp) (!fp.ll[1] && !(fp.ll[0] & HIGH_LL_FRAC_MASK)) #define HIGH_LL_FRAC_BITS 48 #define HIGH_LL_UNIT_BIT ((UDItype_x)1 << HIGH_LL_FRAC_BITS) #define HIGH_LL_FRAC_MASK (HIGH_LL_UNIT_BIT - 1) typedef int DItype_x __attribute__ ((mode (DI))); typedef unsigned int UDItype_x __attribute__ ((mode (DI))); typedef int SItype_x __attribute__ ((mode (SI))); typedef unsigned int USItype_x __attribute__ ((mode (SI))); union double_long { long double d; struct { SItype_x i[4]; /* 32 bit parts: 0 upper ... 3 lowest */ } l; UDItype_x ll[2]; /* 64 bit parts: 0 upper, 1 lower */ }; UDItype_x __fixunstfdi (long double a1); /* convert double to unsigned int */ UDItype_x __fixunstfdi (long double a1) { register union double_long dl1; register int exp; register UDItype_x l; dl1.d = a1; /* +/- 0, denormalized, negative */ if (!EXPD (dl1) || SIGND(dl1)) return 0; /* The exponent - considered the binary point at the right end of the mantissa. */ exp = EXPD (dl1) - EXPONENT_BIAS - MANTISSA_BITS; /* number < 1: If the mantissa would need to be right-shifted more bits than its size (plus the implied one bit on the left) the result would be zero. */ if (exp <= -PRECISION) return 0; /* NaN: All exponent bits set and a nonzero fraction. */ if ((EXPD(dl1) == 0x7fff) && !FRACD_ZERO_P (dl1)) return 0x0ULL; /* One extra bit is needed for the unit bit which is appended by MANTD_HIGH_LL on the left of the matissa. */ exp += HIGH_LL_FRAC_BITS + 1; /* If the result would still need a left shift it will be too large to be represented. */ if (exp > 0) return 0xFFFFFFFFFFFFFFFFULL; l = MANTD_LOW_LL (dl1) >> (HIGH_LL_FRAC_BITS + 1) | MANTD_HIGH_LL (dl1) << (64 - (HIGH_LL_FRAC_BITS + 1)); return l >> -exp; }
Go to most recent revision | Compare with Previous | Blame | View Log