a4cd5630b0
non-i386, non-unix, and generatable files have been trimmed, but can easily be added in later if needed. gcc-2.7.2.1 will follow shortly, it's a very small delta to this and it's handy to have both available for reference for such little cost. The freebsd-specific changes will then be committed, and once the dust has settled, the bmakefiles will be committed to use this code.
1353 lines
29 KiB
C
1353 lines
29 KiB
C
/* This is a software floating point library which can be used instead of
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the floating point routines in libgcc1.c for targets without hardware
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floating point. */
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/* Copyright (C) 1994, 1995 Free Software Foundation, Inc.
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This file is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by the
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Free Software Foundation; either version 2, or (at your option) any
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later version.
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In addition to the permissions in the GNU General Public License, the
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Free Software Foundation gives you unlimited permission to link the
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compiled version of this file with other programs, and to distribute
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those programs without any restriction coming from the use of this
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file. (The General Public License restrictions do apply in other
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respects; for example, they cover modification of the file, and
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distribution when not linked into another program.)
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This file is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; see the file COPYING. If not, write to
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the Free Software Foundation, 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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/* As a special exception, if you link this library with other files,
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some of which are compiled with GCC, to produce an executable,
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this library does not by itself cause the resulting executable
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to be covered by the GNU General Public License.
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This exception does not however invalidate any other reasons why
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the executable file might be covered by the GNU General Public License. */
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/* This implements IEEE 754 format arithmetic, but does not provide a
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mechanism for setting the rounding mode, or for generating or handling
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exceptions.
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The original code by Steve Chamberlain, hacked by Mark Eichin and Jim
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Wilson, all of Cygnus Support. */
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/* The intended way to use this file is to make two copies, add `#define FLOAT'
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to one copy, then compile both copies and add them to libgcc.a. */
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/* The following macros can be defined to change the behaviour of this file:
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FLOAT: Implement a `float', aka SFmode, fp library. If this is not
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defined, then this file implements a `double', aka DFmode, fp library.
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FLOAT_ONLY: Used with FLOAT, to implement a `float' only library, i.e.
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don't include float->double conversion which requires the double library.
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This is useful only for machines which can't support doubles, e.g. some
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8-bit processors.
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CMPtype: Specify the type that floating point compares should return.
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This defaults to SItype, aka int.
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US_SOFTWARE_GOFAST: This makes all entry points use the same names as the
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US Software goFast library. If this is not defined, the entry points use
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the same names as libgcc1.c.
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_DEBUG_BITFLOAT: This makes debugging the code a little easier, by adding
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two integers to the FLO_union_type.
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NO_NANS: Disable nan and infinity handling
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SMALL_MACHINE: Useful when operations on QIs and HIs are faster
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than on an SI */
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typedef SFtype __attribute__ ((mode (SF)));
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typedef DFtype __attribute__ ((mode (DF)));
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typedef int HItype __attribute__ ((mode (HI)));
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typedef int SItype __attribute__ ((mode (SI)));
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typedef int DItype __attribute__ ((mode (DI)));
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/* The type of the result of a fp compare */
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#ifndef CMPtype
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#define CMPtype SItype
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#endif
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typedef unsigned int UHItype __attribute__ ((mode (HI)));
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typedef unsigned int USItype __attribute__ ((mode (SI)));
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typedef unsigned int UDItype __attribute__ ((mode (DI)));
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#define MAX_SI_INT ((SItype) ((unsigned) (~0)>>1))
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#define MAX_USI_INT ((USItype) ~0)
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#ifdef FLOAT_ONLY
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#define NO_DI_MODE
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#endif
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#ifdef FLOAT
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# define NGARDS 7L
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# define GARDROUND 0x3f
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# define GARDMASK 0x7f
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# define GARDMSB 0x40
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# define EXPBITS 8
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# define EXPBIAS 127
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# define FRACBITS 23
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# define EXPMAX (0xff)
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# define QUIET_NAN 0x100000L
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# define FRAC_NBITS 32
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# define FRACHIGH 0x80000000L
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# define FRACHIGH2 0xc0000000L
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# define pack_d pack_f
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# define unpack_d unpack_f
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typedef USItype fractype;
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typedef UHItype halffractype;
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typedef SFtype FLO_type;
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typedef SItype intfrac;
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#else
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# define PREFIXFPDP dp
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# define PREFIXSFDF df
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# define NGARDS 8L
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# define GARDROUND 0x7f
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# define GARDMASK 0xff
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# define GARDMSB 0x80
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# define EXPBITS 11
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# define EXPBIAS 1023
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# define FRACBITS 52
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# define EXPMAX (0x7ff)
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# define QUIET_NAN 0x8000000000000LL
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# define FRAC_NBITS 64
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# define FRACHIGH 0x8000000000000000LL
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# define FRACHIGH2 0xc000000000000000LL
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typedef UDItype fractype;
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typedef USItype halffractype;
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typedef DFtype FLO_type;
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typedef DItype intfrac;
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#endif
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#ifdef US_SOFTWARE_GOFAST
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# ifdef FLOAT
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# define add fpadd
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# define sub fpsub
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# define multiply fpmul
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# define divide fpdiv
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# define compare fpcmp
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# define si_to_float sitofp
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# define float_to_si fptosi
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# define float_to_usi fptoui
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# define negate __negsf2
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# define sf_to_df fptodp
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# define dptofp dptofp
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#else
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# define add dpadd
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# define sub dpsub
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# define multiply dpmul
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# define divide dpdiv
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# define compare dpcmp
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# define si_to_float litodp
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# define float_to_si dptoli
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# define float_to_usi dptoul
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# define negate __negdf2
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# define df_to_sf dptofp
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#endif
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#else
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# ifdef FLOAT
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# define add __addsf3
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# define sub __subsf3
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# define multiply __mulsf3
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# define divide __divsf3
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# define compare __cmpsf2
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# define _eq_f2 __eqsf2
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# define _ne_f2 __nesf2
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# define _gt_f2 __gtsf2
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# define _ge_f2 __gesf2
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# define _lt_f2 __ltsf2
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# define _le_f2 __lesf2
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# define si_to_float __floatsisf
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# define float_to_si __fixsfsi
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# define float_to_usi __fixunssfsi
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# define negate __negsf2
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# define sf_to_df __extendsfdf2
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#else
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# define add __adddf3
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# define sub __subdf3
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# define multiply __muldf3
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# define divide __divdf3
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# define compare __cmpdf2
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# define _eq_f2 __eqdf2
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# define _ne_f2 __nedf2
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# define _gt_f2 __gtdf2
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# define _ge_f2 __gedf2
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# define _lt_f2 __ltdf2
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# define _le_f2 __ledf2
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# define si_to_float __floatsidf
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# define float_to_si __fixdfsi
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# define float_to_usi __fixunsdfsi
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# define negate __negdf2
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# define df_to_sf __truncdfsf2
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# endif
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#endif
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#define INLINE __inline__
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/* Preserve the sticky-bit when shifting fractions to the right. */
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#define LSHIFT(a) { a = (a & 1) | (a >> 1); }
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/* numeric parameters */
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/* F_D_BITOFF is the number of bits offset between the MSB of the mantissa
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of a float and of a double. Assumes there are only two float types.
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(double::FRAC_BITS+double::NGARGS-(float::FRAC_BITS-float::NGARDS))
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*/
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#define F_D_BITOFF (52+8-(23+7))
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#define NORMAL_EXPMIN (-(EXPBIAS)+1)
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#define IMPLICIT_1 (1LL<<(FRACBITS+NGARDS))
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#define IMPLICIT_2 (1LL<<(FRACBITS+1+NGARDS))
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/* common types */
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typedef enum
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{
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CLASS_SNAN,
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CLASS_QNAN,
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CLASS_ZERO,
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CLASS_NUMBER,
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CLASS_INFINITY
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} fp_class_type;
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typedef struct
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{
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#ifdef SMALL_MACHINE
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char class;
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unsigned char sign;
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short normal_exp;
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#else
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fp_class_type class;
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unsigned int sign;
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int normal_exp;
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#endif
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union
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{
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fractype ll;
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halffractype l[2];
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} fraction;
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} fp_number_type;
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typedef union
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{
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FLO_type value;
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fractype value_raw;
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#ifndef FLOAT
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halffractype words[2];
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#endif
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#ifdef FLOAT_BIT_ORDER_MISMATCH
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struct
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{
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fractype fraction:FRACBITS __attribute__ ((packed));
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unsigned int exp:EXPBITS __attribute__ ((packed));
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unsigned int sign:1 __attribute__ ((packed));
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}
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bits;
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#endif
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#ifdef _DEBUG_BITFLOAT
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struct
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{
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unsigned int sign:1 __attribute__ ((packed));
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unsigned int exp:EXPBITS __attribute__ ((packed));
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fractype fraction:FRACBITS __attribute__ ((packed));
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}
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bits_big_endian;
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struct
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{
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fractype fraction:FRACBITS __attribute__ ((packed));
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unsigned int exp:EXPBITS __attribute__ ((packed));
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unsigned int sign:1 __attribute__ ((packed));
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}
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bits_little_endian;
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#endif
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}
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FLO_union_type;
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/* end of header */
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/* IEEE "special" number predicates */
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#ifdef NO_NANS
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#define nan() 0
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#define isnan(x) 0
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#define isinf(x) 0
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#else
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INLINE
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static fp_number_type *
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nan ()
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{
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static fp_number_type thenan;
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return &thenan;
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}
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INLINE
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static int
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isnan ( fp_number_type * x)
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{
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return x->class == CLASS_SNAN || x->class == CLASS_QNAN;
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}
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INLINE
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static int
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isinf ( fp_number_type * x)
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{
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return x->class == CLASS_INFINITY;
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}
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#endif
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INLINE
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static int
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iszero ( fp_number_type * x)
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{
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return x->class == CLASS_ZERO;
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}
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INLINE
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static void
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flip_sign ( fp_number_type * x)
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{
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x->sign = !x->sign;
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}
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static FLO_type
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pack_d ( fp_number_type * src)
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{
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FLO_union_type dst;
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fractype fraction = src->fraction.ll; /* wasn't unsigned before? */
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int sign = src->sign;
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int exp = 0;
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if (isnan (src))
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{
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exp = EXPMAX;
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if (src->class == CLASS_QNAN || 1)
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{
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fraction |= QUIET_NAN;
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}
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}
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else if (isinf (src))
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{
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exp = EXPMAX;
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fraction = 0;
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}
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else if (iszero (src))
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{
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exp = 0;
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fraction = 0;
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}
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else if (fraction == 0)
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{
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exp = 0;
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sign = 0;
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}
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else
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{
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if (src->normal_exp < NORMAL_EXPMIN)
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{
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/* This number's exponent is too low to fit into the bits
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available in the number, so we'll store 0 in the exponent and
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shift the fraction to the right to make up for it. */
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int shift = NORMAL_EXPMIN - src->normal_exp;
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exp = 0;
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if (shift > FRAC_NBITS - NGARDS)
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{
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/* No point shifting, since it's more that 64 out. */
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fraction = 0;
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}
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else
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{
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/* Shift by the value */
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fraction >>= shift;
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}
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fraction >>= NGARDS;
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}
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else if (src->normal_exp > EXPBIAS)
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{
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exp = EXPMAX;
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fraction = 0;
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}
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else
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{
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exp = src->normal_exp + EXPBIAS;
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/* IF the gard bits are the all zero, but the first, then we're
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half way between two numbers, choose the one which makes the
|
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lsb of the answer 0. */
|
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if ((fraction & GARDMASK) == GARDMSB)
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{
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if (fraction & (1 << NGARDS))
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fraction += GARDROUND + 1;
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}
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else
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{
|
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/* Add a one to the guards to round up */
|
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fraction += GARDROUND;
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}
|
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if (fraction >= IMPLICIT_2)
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{
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fraction >>= 1;
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exp += 1;
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}
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fraction >>= NGARDS;
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}
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}
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|
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/* We previously used bitfields to store the number, but this doesn't
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handle little/big endian systems conviently, so use shifts and
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masks */
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#ifdef FLOAT_BIT_ORDER_MISMATCH
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dst.bits.fraction = fraction;
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dst.bits.exp = exp;
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dst.bits.sign = sign;
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#else
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dst.value_raw = fraction & ((((fractype)1) << FRACBITS) - (fractype)1);
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dst.value_raw |= ((fractype) (exp & ((1 << EXPBITS) - 1))) << FRACBITS;
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dst.value_raw |= ((fractype) (sign & 1)) << (FRACBITS | EXPBITS);
|
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#endif
|
|
|
|
#if defined(FLOAT_WORD_ORDER_MISMATCH) && !defined(FLOAT)
|
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{
|
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halffractype tmp = dst.words[0];
|
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dst.words[0] = dst.words[1];
|
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dst.words[1] = tmp;
|
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}
|
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#endif
|
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|
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return dst.value;
|
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}
|
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|
|
static void
|
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unpack_d (FLO_union_type * src, fp_number_type * dst)
|
|
{
|
|
/* We previously used bitfields to store the number, but this doesn't
|
|
handle little/big endian systems conviently, so use shifts and
|
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masks */
|
|
fractype fraction;
|
|
int exp;
|
|
int sign;
|
|
|
|
#if defined(FLOAT_WORD_ORDER_MISMATCH) && !defined(FLOAT)
|
|
FLO_union_type swapped;
|
|
|
|
swapped.words[0] = src->words[1];
|
|
swapped.words[1] = src->words[0];
|
|
src = &swapped;
|
|
#endif
|
|
|
|
#ifdef FLOAT_BIT_ORDER_MISMATCH
|
|
fraction = src->bits.fraction;
|
|
exp = src->bits.exp;
|
|
sign = src->bits.sign;
|
|
#else
|
|
fraction = src->value_raw & ((((fractype)1) << FRACBITS) - (fractype)1);
|
|
exp = ((int)(src->value_raw >> FRACBITS)) & ((1 << EXPBITS) - 1);
|
|
sign = ((int)(src->value_raw >> (FRACBITS + EXPBITS))) & 1;
|
|
#endif
|
|
|
|
dst->sign = sign;
|
|
if (exp == 0)
|
|
{
|
|
/* Hmm. Looks like 0 */
|
|
if (fraction == 0)
|
|
{
|
|
/* tastes like zero */
|
|
dst->class = CLASS_ZERO;
|
|
}
|
|
else
|
|
{
|
|
/* Zero exponent with non zero fraction - it's denormalized,
|
|
so there isn't a leading implicit one - we'll shift it so
|
|
it gets one. */
|
|
dst->normal_exp = exp - EXPBIAS + 1;
|
|
fraction <<= NGARDS;
|
|
|
|
dst->class = CLASS_NUMBER;
|
|
#if 1
|
|
while (fraction < IMPLICIT_1)
|
|
{
|
|
fraction <<= 1;
|
|
dst->normal_exp--;
|
|
}
|
|
#endif
|
|
dst->fraction.ll = fraction;
|
|
}
|
|
}
|
|
else if (exp == EXPMAX)
|
|
{
|
|
/* Huge exponent*/
|
|
if (fraction == 0)
|
|
{
|
|
/* Attached to a zero fraction - means infinity */
|
|
dst->class = CLASS_INFINITY;
|
|
}
|
|
else
|
|
{
|
|
/* Non zero fraction, means nan */
|
|
if (sign)
|
|
{
|
|
dst->class = CLASS_SNAN;
|
|
}
|
|
else
|
|
{
|
|
dst->class = CLASS_QNAN;
|
|
}
|
|
/* Keep the fraction part as the nan number */
|
|
dst->fraction.ll = fraction;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Nothing strange about this number */
|
|
dst->normal_exp = exp - EXPBIAS;
|
|
dst->class = CLASS_NUMBER;
|
|
dst->fraction.ll = (fraction << NGARDS) | IMPLICIT_1;
|
|
}
|
|
}
|
|
|
|
static fp_number_type *
|
|
_fpadd_parts (fp_number_type * a,
|
|
fp_number_type * b,
|
|
fp_number_type * tmp)
|
|
{
|
|
intfrac tfraction;
|
|
|
|
/* Put commonly used fields in local variables. */
|
|
int a_normal_exp;
|
|
int b_normal_exp;
|
|
fractype a_fraction;
|
|
fractype b_fraction;
|
|
|
|
if (isnan (a))
|
|
{
|
|
return a;
|
|
}
|
|
if (isnan (b))
|
|
{
|
|
return b;
|
|
}
|
|
if (isinf (a))
|
|
{
|
|
/* Adding infinities with opposite signs yields a NaN. */
|
|
if (isinf (b) && a->sign != b->sign)
|
|
return nan ();
|
|
return a;
|
|
}
|
|
if (isinf (b))
|
|
{
|
|
return b;
|
|
}
|
|
if (iszero (b))
|
|
{
|
|
return a;
|
|
}
|
|
if (iszero (a))
|
|
{
|
|
return b;
|
|
}
|
|
|
|
/* Got two numbers. shift the smaller and increment the exponent till
|
|
they're the same */
|
|
{
|
|
int diff;
|
|
|
|
a_normal_exp = a->normal_exp;
|
|
b_normal_exp = b->normal_exp;
|
|
a_fraction = a->fraction.ll;
|
|
b_fraction = b->fraction.ll;
|
|
|
|
diff = a_normal_exp - b_normal_exp;
|
|
|
|
if (diff < 0)
|
|
diff = -diff;
|
|
if (diff < FRAC_NBITS)
|
|
{
|
|
/* ??? This does shifts one bit at a time. Optimize. */
|
|
while (a_normal_exp > b_normal_exp)
|
|
{
|
|
b_normal_exp++;
|
|
LSHIFT (b_fraction);
|
|
}
|
|
while (b_normal_exp > a_normal_exp)
|
|
{
|
|
a_normal_exp++;
|
|
LSHIFT (a_fraction);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Somethings's up.. choose the biggest */
|
|
if (a_normal_exp > b_normal_exp)
|
|
{
|
|
b_normal_exp = a_normal_exp;
|
|
b_fraction = 0;
|
|
}
|
|
else
|
|
{
|
|
a_normal_exp = b_normal_exp;
|
|
a_fraction = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (a->sign != b->sign)
|
|
{
|
|
if (a->sign)
|
|
{
|
|
tfraction = -a_fraction + b_fraction;
|
|
}
|
|
else
|
|
{
|
|
tfraction = a_fraction - b_fraction;
|
|
}
|
|
if (tfraction > 0)
|
|
{
|
|
tmp->sign = 0;
|
|
tmp->normal_exp = a_normal_exp;
|
|
tmp->fraction.ll = tfraction;
|
|
}
|
|
else
|
|
{
|
|
tmp->sign = 1;
|
|
tmp->normal_exp = a_normal_exp;
|
|
tmp->fraction.ll = -tfraction;
|
|
}
|
|
/* and renormalize it */
|
|
|
|
while (tmp->fraction.ll < IMPLICIT_1 && tmp->fraction.ll)
|
|
{
|
|
tmp->fraction.ll <<= 1;
|
|
tmp->normal_exp--;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
tmp->sign = a->sign;
|
|
tmp->normal_exp = a_normal_exp;
|
|
tmp->fraction.ll = a_fraction + b_fraction;
|
|
}
|
|
tmp->class = CLASS_NUMBER;
|
|
/* Now the fraction is added, we have to shift down to renormalize the
|
|
number */
|
|
|
|
if (tmp->fraction.ll >= IMPLICIT_2)
|
|
{
|
|
LSHIFT (tmp->fraction.ll);
|
|
tmp->normal_exp++;
|
|
}
|
|
return tmp;
|
|
|
|
}
|
|
|
|
FLO_type
|
|
add (FLO_type arg_a, FLO_type arg_b)
|
|
{
|
|
fp_number_type a;
|
|
fp_number_type b;
|
|
fp_number_type tmp;
|
|
fp_number_type *res;
|
|
|
|
unpack_d ((FLO_union_type *) & arg_a, &a);
|
|
unpack_d ((FLO_union_type *) & arg_b, &b);
|
|
|
|
res = _fpadd_parts (&a, &b, &tmp);
|
|
|
|
return pack_d (res);
|
|
}
|
|
|
|
FLO_type
|
|
sub (FLO_type arg_a, FLO_type arg_b)
|
|
{
|
|
fp_number_type a;
|
|
fp_number_type b;
|
|
fp_number_type tmp;
|
|
fp_number_type *res;
|
|
|
|
unpack_d ((FLO_union_type *) & arg_a, &a);
|
|
unpack_d ((FLO_union_type *) & arg_b, &b);
|
|
|
|
b.sign ^= 1;
|
|
|
|
res = _fpadd_parts (&a, &b, &tmp);
|
|
|
|
return pack_d (res);
|
|
}
|
|
|
|
static fp_number_type *
|
|
_fpmul_parts ( fp_number_type * a,
|
|
fp_number_type * b,
|
|
fp_number_type * tmp)
|
|
{
|
|
fractype low = 0;
|
|
fractype high = 0;
|
|
|
|
if (isnan (a))
|
|
{
|
|
a->sign = a->sign != b->sign;
|
|
return a;
|
|
}
|
|
if (isnan (b))
|
|
{
|
|
b->sign = a->sign != b->sign;
|
|
return b;
|
|
}
|
|
if (isinf (a))
|
|
{
|
|
if (iszero (b))
|
|
return nan ();
|
|
a->sign = a->sign != b->sign;
|
|
return a;
|
|
}
|
|
if (isinf (b))
|
|
{
|
|
if (iszero (a))
|
|
{
|
|
return nan ();
|
|
}
|
|
b->sign = a->sign != b->sign;
|
|
return b;
|
|
}
|
|
if (iszero (a))
|
|
{
|
|
a->sign = a->sign != b->sign;
|
|
return a;
|
|
}
|
|
if (iszero (b))
|
|
{
|
|
b->sign = a->sign != b->sign;
|
|
return b;
|
|
}
|
|
|
|
/* Calculate the mantissa by multiplying both 64bit numbers to get a
|
|
128 bit number */
|
|
{
|
|
fractype x = a->fraction.ll;
|
|
fractype ylow = b->fraction.ll;
|
|
fractype yhigh = 0;
|
|
int bit;
|
|
|
|
#if defined(NO_DI_MODE)
|
|
{
|
|
/* ??? This does multiplies one bit at a time. Optimize. */
|
|
for (bit = 0; bit < FRAC_NBITS; bit++)
|
|
{
|
|
int carry;
|
|
|
|
if (x & 1)
|
|
{
|
|
carry = (low += ylow) < ylow;
|
|
high += yhigh + carry;
|
|
}
|
|
yhigh <<= 1;
|
|
if (ylow & FRACHIGH)
|
|
{
|
|
yhigh |= 1;
|
|
}
|
|
ylow <<= 1;
|
|
x >>= 1;
|
|
}
|
|
}
|
|
#elif defined(FLOAT)
|
|
{
|
|
/* Multiplying two 32 bit numbers to get a 64 bit number on
|
|
a machine with DI, so we're safe */
|
|
|
|
DItype answer = (DItype)(a->fraction.ll) * (DItype)(b->fraction.ll);
|
|
|
|
high = answer >> 32;
|
|
low = answer;
|
|
}
|
|
#else
|
|
/* Doing a 64*64 to 128 */
|
|
{
|
|
UDItype nl = a->fraction.ll & 0xffffffff;
|
|
UDItype nh = a->fraction.ll >> 32;
|
|
UDItype ml = b->fraction.ll & 0xffffffff;
|
|
UDItype mh = b->fraction.ll >>32;
|
|
UDItype pp_ll = ml * nl;
|
|
UDItype pp_hl = mh * nl;
|
|
UDItype pp_lh = ml * nh;
|
|
UDItype pp_hh = mh * nh;
|
|
UDItype res2 = 0;
|
|
UDItype res0 = 0;
|
|
UDItype ps_hh__ = pp_hl + pp_lh;
|
|
if (ps_hh__ < pp_hl)
|
|
res2 += 0x100000000LL;
|
|
pp_hl = (ps_hh__ << 32) & 0xffffffff00000000LL;
|
|
res0 = pp_ll + pp_hl;
|
|
if (res0 < pp_ll)
|
|
res2++;
|
|
res2 += ((ps_hh__ >> 32) & 0xffffffffL) + pp_hh;
|
|
high = res2;
|
|
low = res0;
|
|
}
|
|
#endif
|
|
}
|
|
|
|
tmp->normal_exp = a->normal_exp + b->normal_exp;
|
|
tmp->sign = a->sign != b->sign;
|
|
#ifdef FLOAT
|
|
tmp->normal_exp += 2; /* ??????????????? */
|
|
#else
|
|
tmp->normal_exp += 4; /* ??????????????? */
|
|
#endif
|
|
while (high >= IMPLICIT_2)
|
|
{
|
|
tmp->normal_exp++;
|
|
if (high & 1)
|
|
{
|
|
low >>= 1;
|
|
low |= FRACHIGH;
|
|
}
|
|
high >>= 1;
|
|
}
|
|
while (high < IMPLICIT_1)
|
|
{
|
|
tmp->normal_exp--;
|
|
|
|
high <<= 1;
|
|
if (low & FRACHIGH)
|
|
high |= 1;
|
|
low <<= 1;
|
|
}
|
|
/* rounding is tricky. if we only round if it won't make us round later. */
|
|
#if 0
|
|
if (low & FRACHIGH2)
|
|
{
|
|
if (((high & GARDMASK) != GARDMSB)
|
|
&& (((high + 1) & GARDMASK) == GARDMSB))
|
|
{
|
|
/* don't round, it gets done again later. */
|
|
}
|
|
else
|
|
{
|
|
high++;
|
|
}
|
|
}
|
|
#endif
|
|
if ((high & GARDMASK) == GARDMSB)
|
|
{
|
|
if (high & (1 << NGARDS))
|
|
{
|
|
/* half way, so round to even */
|
|
high += GARDROUND + 1;
|
|
}
|
|
else if (low)
|
|
{
|
|
/* but we really weren't half way */
|
|
high += GARDROUND + 1;
|
|
}
|
|
}
|
|
tmp->fraction.ll = high;
|
|
tmp->class = CLASS_NUMBER;
|
|
return tmp;
|
|
}
|
|
|
|
FLO_type
|
|
multiply (FLO_type arg_a, FLO_type arg_b)
|
|
{
|
|
fp_number_type a;
|
|
fp_number_type b;
|
|
fp_number_type tmp;
|
|
fp_number_type *res;
|
|
|
|
unpack_d ((FLO_union_type *) & arg_a, &a);
|
|
unpack_d ((FLO_union_type *) & arg_b, &b);
|
|
|
|
res = _fpmul_parts (&a, &b, &tmp);
|
|
|
|
return pack_d (res);
|
|
}
|
|
|
|
static fp_number_type *
|
|
_fpdiv_parts (fp_number_type * a,
|
|
fp_number_type * b,
|
|
fp_number_type * tmp)
|
|
{
|
|
fractype low = 0;
|
|
fractype high = 0;
|
|
fractype r0, r1, y0, y1, bit;
|
|
fractype q;
|
|
fractype numerator;
|
|
fractype denominator;
|
|
fractype quotient;
|
|
fractype remainder;
|
|
|
|
if (isnan (a))
|
|
{
|
|
return a;
|
|
}
|
|
if (isnan (b))
|
|
{
|
|
return b;
|
|
}
|
|
if (isinf (a) || iszero (a))
|
|
{
|
|
if (a->class == b->class)
|
|
return nan ();
|
|
return a;
|
|
}
|
|
a->sign = a->sign ^ b->sign;
|
|
|
|
if (isinf (b))
|
|
{
|
|
a->fraction.ll = 0;
|
|
a->normal_exp = 0;
|
|
return a;
|
|
}
|
|
if (iszero (b))
|
|
{
|
|
a->class = CLASS_INFINITY;
|
|
return b;
|
|
}
|
|
|
|
/* Calculate the mantissa by multiplying both 64bit numbers to get a
|
|
128 bit number */
|
|
{
|
|
int carry;
|
|
intfrac d0, d1; /* weren't unsigned before ??? */
|
|
|
|
/* quotient =
|
|
( numerator / denominator) * 2^(numerator exponent - denominator exponent)
|
|
*/
|
|
|
|
a->normal_exp = a->normal_exp - b->normal_exp;
|
|
numerator = a->fraction.ll;
|
|
denominator = b->fraction.ll;
|
|
|
|
if (numerator < denominator)
|
|
{
|
|
/* Fraction will be less than 1.0 */
|
|
numerator *= 2;
|
|
a->normal_exp--;
|
|
}
|
|
bit = IMPLICIT_1;
|
|
quotient = 0;
|
|
/* ??? Does divide one bit at a time. Optimize. */
|
|
while (bit)
|
|
{
|
|
if (numerator >= denominator)
|
|
{
|
|
quotient |= bit;
|
|
numerator -= denominator;
|
|
}
|
|
bit >>= 1;
|
|
numerator *= 2;
|
|
}
|
|
|
|
if ((quotient & GARDMASK) == GARDMSB)
|
|
{
|
|
if (quotient & (1 << NGARDS))
|
|
{
|
|
/* half way, so round to even */
|
|
quotient += GARDROUND + 1;
|
|
}
|
|
else if (numerator)
|
|
{
|
|
/* but we really weren't half way, more bits exist */
|
|
quotient += GARDROUND + 1;
|
|
}
|
|
}
|
|
|
|
a->fraction.ll = quotient;
|
|
return (a);
|
|
}
|
|
}
|
|
|
|
FLO_type
|
|
divide (FLO_type arg_a, FLO_type arg_b)
|
|
{
|
|
fp_number_type a;
|
|
fp_number_type b;
|
|
fp_number_type tmp;
|
|
fp_number_type *res;
|
|
|
|
unpack_d ((FLO_union_type *) & arg_a, &a);
|
|
unpack_d ((FLO_union_type *) & arg_b, &b);
|
|
|
|
res = _fpdiv_parts (&a, &b, &tmp);
|
|
|
|
return pack_d (res);
|
|
}
|
|
|
|
/* according to the demo, fpcmp returns a comparison with 0... thus
|
|
a<b -> -1
|
|
a==b -> 0
|
|
a>b -> +1
|
|
*/
|
|
|
|
static int
|
|
_fpcmp_parts (fp_number_type * a, fp_number_type * b)
|
|
{
|
|
#if 0
|
|
/* either nan -> unordered. Must be checked outside of this routine. */
|
|
if (isnan (a) && isnan (b))
|
|
{
|
|
return 1; /* still unordered! */
|
|
}
|
|
#endif
|
|
|
|
if (isnan (a) || isnan (b))
|
|
{
|
|
return 1; /* how to indicate unordered compare? */
|
|
}
|
|
if (isinf (a) && isinf (b))
|
|
{
|
|
/* +inf > -inf, but +inf != +inf */
|
|
/* b \a| +inf(0)| -inf(1)
|
|
______\+--------+--------
|
|
+inf(0)| a==b(0)| a<b(-1)
|
|
-------+--------+--------
|
|
-inf(1)| a>b(1) | a==b(0)
|
|
-------+--------+--------
|
|
So since unordered must be non zero, just line up the columns...
|
|
*/
|
|
return b->sign - a->sign;
|
|
}
|
|
/* but not both... */
|
|
if (isinf (a))
|
|
{
|
|
return a->sign ? -1 : 1;
|
|
}
|
|
if (isinf (b))
|
|
{
|
|
return b->sign ? 1 : -1;
|
|
}
|
|
if (iszero (a) && iszero (b))
|
|
{
|
|
return 0;
|
|
}
|
|
if (iszero (a))
|
|
{
|
|
return b->sign ? 1 : -1;
|
|
}
|
|
if (iszero (b))
|
|
{
|
|
return a->sign ? -1 : 1;
|
|
}
|
|
/* now both are "normal". */
|
|
if (a->sign != b->sign)
|
|
{
|
|
/* opposite signs */
|
|
return a->sign ? -1 : 1;
|
|
}
|
|
/* same sign; exponents? */
|
|
if (a->normal_exp > b->normal_exp)
|
|
{
|
|
return a->sign ? -1 : 1;
|
|
}
|
|
if (a->normal_exp < b->normal_exp)
|
|
{
|
|
return a->sign ? 1 : -1;
|
|
}
|
|
/* same exponents; check size. */
|
|
if (a->fraction.ll > b->fraction.ll)
|
|
{
|
|
return a->sign ? -1 : 1;
|
|
}
|
|
if (a->fraction.ll < b->fraction.ll)
|
|
{
|
|
return a->sign ? 1 : -1;
|
|
}
|
|
/* after all that, they're equal. */
|
|
return 0;
|
|
}
|
|
|
|
CMPtype
|
|
compare (FLO_type arg_a, FLO_type arg_b)
|
|
{
|
|
fp_number_type a;
|
|
fp_number_type b;
|
|
|
|
unpack_d ((FLO_union_type *) & arg_a, &a);
|
|
unpack_d ((FLO_union_type *) & arg_b, &b);
|
|
|
|
return _fpcmp_parts (&a, &b);
|
|
}
|
|
|
|
#ifndef US_SOFTWARE_GOFAST
|
|
|
|
/* These should be optimized for their specific tasks someday. */
|
|
|
|
CMPtype
|
|
_eq_f2 (FLO_type arg_a, FLO_type arg_b)
|
|
{
|
|
fp_number_type a;
|
|
fp_number_type b;
|
|
|
|
unpack_d ((FLO_union_type *) & arg_a, &a);
|
|
unpack_d ((FLO_union_type *) & arg_b, &b);
|
|
|
|
if (isnan (&a) || isnan (&b))
|
|
return 1; /* false, truth == 0 */
|
|
|
|
return _fpcmp_parts (&a, &b) ;
|
|
}
|
|
|
|
CMPtype
|
|
_ne_f2 (FLO_type arg_a, FLO_type arg_b)
|
|
{
|
|
fp_number_type a;
|
|
fp_number_type b;
|
|
|
|
unpack_d ((FLO_union_type *) & arg_a, &a);
|
|
unpack_d ((FLO_union_type *) & arg_b, &b);
|
|
|
|
if (isnan (&a) || isnan (&b))
|
|
return 1; /* true, truth != 0 */
|
|
|
|
return _fpcmp_parts (&a, &b) ;
|
|
}
|
|
|
|
CMPtype
|
|
_gt_f2 (FLO_type arg_a, FLO_type arg_b)
|
|
{
|
|
fp_number_type a;
|
|
fp_number_type b;
|
|
|
|
unpack_d ((FLO_union_type *) & arg_a, &a);
|
|
unpack_d ((FLO_union_type *) & arg_b, &b);
|
|
|
|
if (isnan (&a) || isnan (&b))
|
|
return -1; /* false, truth > 0 */
|
|
|
|
return _fpcmp_parts (&a, &b);
|
|
}
|
|
|
|
CMPtype
|
|
_ge_f2 (FLO_type arg_a, FLO_type arg_b)
|
|
{
|
|
fp_number_type a;
|
|
fp_number_type b;
|
|
|
|
unpack_d ((FLO_union_type *) & arg_a, &a);
|
|
unpack_d ((FLO_union_type *) & arg_b, &b);
|
|
|
|
if (isnan (&a) || isnan (&b))
|
|
return -1; /* false, truth >= 0 */
|
|
return _fpcmp_parts (&a, &b) ;
|
|
}
|
|
|
|
CMPtype
|
|
_lt_f2 (FLO_type arg_a, FLO_type arg_b)
|
|
{
|
|
fp_number_type a;
|
|
fp_number_type b;
|
|
|
|
unpack_d ((FLO_union_type *) & arg_a, &a);
|
|
unpack_d ((FLO_union_type *) & arg_b, &b);
|
|
|
|
if (isnan (&a) || isnan (&b))
|
|
return 1; /* false, truth < 0 */
|
|
|
|
return _fpcmp_parts (&a, &b);
|
|
}
|
|
|
|
CMPtype
|
|
_le_f2 (FLO_type arg_a, FLO_type arg_b)
|
|
{
|
|
fp_number_type a;
|
|
fp_number_type b;
|
|
|
|
unpack_d ((FLO_union_type *) & arg_a, &a);
|
|
unpack_d ((FLO_union_type *) & arg_b, &b);
|
|
|
|
if (isnan (&a) || isnan (&b))
|
|
return 1; /* false, truth <= 0 */
|
|
|
|
return _fpcmp_parts (&a, &b) ;
|
|
}
|
|
|
|
#endif /* ! US_SOFTWARE_GOFAST */
|
|
|
|
FLO_type
|
|
si_to_float (SItype arg_a)
|
|
{
|
|
fp_number_type in;
|
|
|
|
in.class = CLASS_NUMBER;
|
|
in.sign = arg_a < 0;
|
|
if (!arg_a)
|
|
{
|
|
in.class = CLASS_ZERO;
|
|
}
|
|
else
|
|
{
|
|
in.normal_exp = FRACBITS + NGARDS;
|
|
if (in.sign)
|
|
{
|
|
/* Special case for minint, since there is no +ve integer
|
|
representation for it */
|
|
if (arg_a == 0x80000000)
|
|
{
|
|
return -2147483648.0;
|
|
}
|
|
in.fraction.ll = (-arg_a);
|
|
}
|
|
else
|
|
in.fraction.ll = arg_a;
|
|
|
|
while (in.fraction.ll < (1LL << (FRACBITS + NGARDS)))
|
|
{
|
|
in.fraction.ll <<= 1;
|
|
in.normal_exp -= 1;
|
|
}
|
|
}
|
|
return pack_d (&in);
|
|
}
|
|
|
|
SItype
|
|
float_to_si (FLO_type arg_a)
|
|
{
|
|
fp_number_type a;
|
|
SItype tmp;
|
|
|
|
unpack_d ((FLO_union_type *) & arg_a, &a);
|
|
if (iszero (&a))
|
|
return 0;
|
|
if (isnan (&a))
|
|
return 0;
|
|
/* get reasonable MAX_SI_INT... */
|
|
if (isinf (&a))
|
|
return a.sign ? MAX_SI_INT : (-MAX_SI_INT)-1;
|
|
/* it is a number, but a small one */
|
|
if (a.normal_exp < 0)
|
|
return 0;
|
|
if (a.normal_exp > 30)
|
|
return a.sign ? (-MAX_SI_INT)-1 : MAX_SI_INT;
|
|
tmp = a.fraction.ll >> ((FRACBITS + NGARDS) - a.normal_exp);
|
|
return a.sign ? (-tmp) : (tmp);
|
|
}
|
|
|
|
#ifdef US_SOFTWARE_GOFAST
|
|
/* While libgcc2.c defines its own __fixunssfsi and __fixunsdfsi routines,
|
|
we also define them for GOFAST because the ones in libgcc2.c have the
|
|
wrong names and I'd rather define these here and keep GOFAST CYG-LOC's
|
|
out of libgcc2.c. We can't define these here if not GOFAST because then
|
|
there'd be duplicate copies. */
|
|
|
|
USItype
|
|
float_to_usi (FLO_type arg_a)
|
|
{
|
|
fp_number_type a;
|
|
|
|
unpack_d ((FLO_union_type *) & arg_a, &a);
|
|
if (iszero (&a))
|
|
return 0;
|
|
if (isnan (&a))
|
|
return 0;
|
|
/* get reasonable MAX_USI_INT... */
|
|
if (isinf (&a))
|
|
return a.sign ? MAX_USI_INT : 0;
|
|
/* it is a negative number */
|
|
if (a.sign)
|
|
return 0;
|
|
/* it is a number, but a small one */
|
|
if (a.normal_exp < 0)
|
|
return 0;
|
|
if (a.normal_exp > 31)
|
|
return MAX_USI_INT;
|
|
else if (a.normal_exp > (FRACBITS + NGARDS))
|
|
return a.fraction.ll << ((FRACBITS + NGARDS) - a.normal_exp);
|
|
else
|
|
return a.fraction.ll >> ((FRACBITS + NGARDS) - a.normal_exp);
|
|
}
|
|
#endif
|
|
|
|
FLO_type
|
|
negate (FLO_type arg_a)
|
|
{
|
|
fp_number_type a;
|
|
|
|
unpack_d ((FLO_union_type *) & arg_a, &a);
|
|
flip_sign (&a);
|
|
return pack_d (&a);
|
|
}
|
|
|
|
#ifdef FLOAT
|
|
|
|
SFtype
|
|
__make_fp(fp_class_type class,
|
|
unsigned int sign,
|
|
int exp,
|
|
USItype frac)
|
|
{
|
|
fp_number_type in;
|
|
|
|
in.class = class;
|
|
in.sign = sign;
|
|
in.normal_exp = exp;
|
|
in.fraction.ll = frac;
|
|
return pack_d (&in);
|
|
}
|
|
|
|
#ifndef FLOAT_ONLY
|
|
|
|
/* This enables one to build an fp library that supports float but not double.
|
|
Otherwise, we would get an undefined reference to __make_dp.
|
|
This is needed for some 8-bit ports that can't handle well values that
|
|
are 8-bytes in size, so we just don't support double for them at all. */
|
|
|
|
extern DFtype __make_dp (fp_class_type, unsigned int, int, UDItype frac);
|
|
|
|
DFtype
|
|
sf_to_df (SFtype arg_a)
|
|
{
|
|
fp_number_type in;
|
|
|
|
unpack_d ((FLO_union_type *) & arg_a, &in);
|
|
return __make_dp (in.class, in.sign, in.normal_exp,
|
|
((UDItype) in.fraction.ll) << F_D_BITOFF);
|
|
}
|
|
|
|
#endif
|
|
#endif
|
|
|
|
#ifndef FLOAT
|
|
|
|
extern SFtype __make_fp (fp_class_type, unsigned int, int, USItype);
|
|
|
|
DFtype
|
|
__make_dp (fp_class_type class, unsigned int sign, int exp, UDItype frac)
|
|
{
|
|
fp_number_type in;
|
|
|
|
in.class = class;
|
|
in.sign = sign;
|
|
in.normal_exp = exp;
|
|
in.fraction.ll = frac;
|
|
return pack_d (&in);
|
|
}
|
|
|
|
SFtype
|
|
df_to_sf (DFtype arg_a)
|
|
{
|
|
fp_number_type in;
|
|
|
|
unpack_d ((FLO_union_type *) & arg_a, &in);
|
|
return __make_fp (in.class, in.sign, in.normal_exp,
|
|
in.fraction.ll >> F_D_BITOFF);
|
|
}
|
|
|
|
#endif
|