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Diffstat (limited to 'libgcc/config/s390/32/_fixunstfdi.c')
-rw-r--r-- | libgcc/config/s390/32/_fixunstfdi.c | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/libgcc/config/s390/32/_fixunstfdi.c b/libgcc/config/s390/32/_fixunstfdi.c new file mode 100644 index 0000000000..b3b243f94c --- /dev/null +++ b/libgcc/config/s390/32/_fixunstfdi.c @@ -0,0 +1,125 @@ +/* Definitions of target machine for GNU compiler, for IBM S/390 + Copyright (C) 1999-2017 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/>. */ + +#ifndef __s390x__ + +#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 */ +}; + +static __inline__ void +fexceptdiv (float d, float e) +{ + __asm__ __volatile__ ("debr %0,%1" : : "f" (d), "f" (e) ); +} + +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 */ + if (!EXPD (dl1)) + return 0; + + /* Negative. */ + if (SIGND (dl1)) + { + /* Value is <= -1.0 + C99 Annex F.4 requires an "invalid" exception to be thrown. */ + if (EXPD (dl1) >= EXPONENT_BIAS) + fexceptdiv (0.0, 0.0); + 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)) + { + /* C99 Annex F.4 requires an "invalid" exception to be thrown. */ + fexceptdiv (0.0, 0.0); + return 0; + } + + /* 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. Infinities have all exponent bits set + and will end up here as well. */ + if (exp > 0) + { + /* C99 Annex F.4 requires an "invalid" exception to be thrown. */ + fexceptdiv (0.0, 0.0); + 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; +} + +#endif /* !__s390x__ */ |