285 lines
7 KiB
C
285 lines
7 KiB
C
/****************************************************************
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*
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* The author of this software is David M. Gay.
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*
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* Copyright (c) 1991 by AT&T.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose without fee is hereby granted, provided that this entire notice
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* is included in all copies of any software which is or includes a copy
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* or modification of this software and in all copies of the supporting
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* documentation for such software.
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*
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* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
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* WARRANTY. IN PARTICULAR, NEITHER THE AUTHOR NOR AT&T MAKES ANY
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* REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
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* OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
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*
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***************************************************************/
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/* Please send bug reports to
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David M. Gay
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AT&T Bell Laboratories, Room 2C-463
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600 Mountain Avenue
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Murray Hill, NJ 07974-2070
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U.S.A.
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dmg@research.att.com or research!dmg
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*/
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/* This header file is a modification of mprec.h that only contains floating
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point union code. */
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#include <ieeefp.h>
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#include <math.h>
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#include <float.h>
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#include <errno.h>
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#include <sys/config.h>
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#ifdef __IEEE_LITTLE_ENDIAN
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#define IEEE_8087
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#endif
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#ifdef __IEEE_BIG_ENDIAN
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#define IEEE_MC68k
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#endif
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#ifdef __Z8000__
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#define Just_16
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#endif
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#ifdef Unsigned_Shifts
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#define Sign_Extend(a,b) if (b < 0) a |= (__uint32_t)0xffff0000;
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#else
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#define Sign_Extend(a,b) /*no-op*/
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#endif
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#if defined(IEEE_8087) + defined(IEEE_MC68k) + defined(VAX) + defined(IBM) != 1
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Exactly one of IEEE_8087, IEEE_MC68k, VAX, or IBM should be defined.
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#endif
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#ifdef WANT_IO_LONG_DBL
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/* If we are going to examine or modify specific bits in a long double using
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the lword0 or lwordx macros, then we must wrap the long double inside
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a union. This is necessary to avoid undefined behavior according to
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the ANSI C spec. */
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#ifdef IEEE_8087
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#if LDBL_MANT_DIG == 24
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struct ldieee
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{
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unsigned manh:23;
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unsigned exp:8;
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unsigned sign:1;
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};
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#elif LDBL_MANT_DIG == 53
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struct ldieee
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{
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unsigned manl:20;
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unsigned manh:32;
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unsigned exp:11;
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unsigned sign:1;
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};
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#elif LDBL_MANT_DIG == 64
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struct ldieee
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{
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unsigned manl:32;
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unsigned manh:32;
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unsigned exp:15;
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unsigned sign:1;
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};
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#elif LDBL_MANT_DIG > 64
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struct ldieee
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{
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unsigned manl3:16;
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unsigned manl2:32;
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unsigned manl:32;
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unsigned manh:32;
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unsigned exp:15;
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unsigned sign:1;
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};
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#endif /* LDBL_MANT_DIG */
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#else /* !IEEE_8087 */
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#if LDBL_MANT_DIG == 24
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struct ldieee
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{
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unsigned sign:1;
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unsigned exp:8;
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unsigned manh:23;
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};
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#elif LDBL_MANT_DIG == 53
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struct ldieee
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{
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unsigned sign:1;
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unsigned exp:11;
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unsigned manh:32;
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unsigned manl:20;
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};
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#elif LDBL_MANT_DIG == 64
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struct ldieee
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{
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unsigned sign:1;
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unsigned exp:15;
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unsigned manh:32;
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unsigned manl:32;
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};
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#elif LDBL_MANT_DIG > 64
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struct ldieee
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{
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unsigned sign:1;
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unsigned exp:15;
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unsigned manh:32;
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unsigned manl:32;
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unsigned manl2:32;
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unsigned manl3;16;
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};
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#endif /* LDBL_MANT_DIG */
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#endif /* !IEEE_8087 */
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#endif /* WANT_IO_LONG_DBL */
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/* If we are going to examine or modify specific bits in a double using
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the word0 and/or word1 macros, then we must wrap the double inside
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a union. This is necessary to avoid undefined behavior according to
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the ANSI C spec. */
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union double_union
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{
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double d;
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__uint32_t i[2];
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};
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#ifdef IEEE_8087
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#define word0(x) (x.i[1])
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#define word1(x) (x.i[0])
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#else
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#define word0(x) (x.i[0])
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#define word1(x) (x.i[1])
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#endif
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/* #define P DBL_MANT_DIG */
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/* Ten_pmax = floor(P*log(2)/log(5)) */
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/* Bletch = (highest power of 2 < DBL_MAX_10_EXP) / 16 */
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/* Quick_max = floor((P-1)*log(FLT_RADIX)/log(10) - 1) */
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/* Int_max = floor(P*log(FLT_RADIX)/log(10) - 1) */
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#if defined(IEEE_8087) + defined(IEEE_MC68k)
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#if defined (_DOUBLE_IS_32BITS)
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#define Exp_shift 23
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#define Exp_shift1 23
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#define Exp_msk1 ((__uint32_t)0x00800000L)
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#define Exp_msk11 ((__uint32_t)0x00800000L)
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#define Exp_mask ((__uint32_t)0x7f800000L)
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#define P 24
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#define Bias 127
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#if 0
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#define IEEE_Arith /* it is, but the code doesn't handle IEEE singles yet */
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#endif
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#define Emin (-126)
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#define Exp_1 ((__uint32_t)0x3f800000L)
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#define Exp_11 ((__uint32_t)0x3f800000L)
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#define Ebits 8
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#define Frac_mask ((__uint32_t)0x007fffffL)
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#define Frac_mask1 ((__uint32_t)0x007fffffL)
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#define Ten_pmax 10
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#define Sign_bit ((__uint32_t)0x80000000L)
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#define Ten_pmax 10
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#define Bletch 2
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#define Bndry_mask ((__uint32_t)0x007fffffL)
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#define Bndry_mask1 ((__uint32_t)0x007fffffL)
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#define LSB 1
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#define Sign_bit ((__uint32_t)0x80000000L)
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#define Log2P 1
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#define Tiny0 0
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#define Tiny1 1
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#define Quick_max 5
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#define Int_max 6
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#define Infinite(x) (word0(x) == ((__uint32_t)0x7f800000L))
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#undef word0
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#undef word1
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#define word0(x) (x.i[0])
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#define word1(x) 0
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#else
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#define Exp_shift 20
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#define Exp_shift1 20
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#define Exp_msk1 ((__uint32_t)0x100000L)
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#define Exp_msk11 ((__uint32_t)0x100000L)
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#define Exp_mask ((__uint32_t)0x7ff00000L)
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#define P 53
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#define Bias 1023
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#define IEEE_Arith
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#define Emin (-1022)
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#define Exp_1 ((__uint32_t)0x3ff00000L)
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#define Exp_11 ((__uint32_t)0x3ff00000L)
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#define Ebits 11
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#define Frac_mask ((__uint32_t)0xfffffL)
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#define Frac_mask1 ((__uint32_t)0xfffffL)
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#define Ten_pmax 22
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#define Bletch 0x10
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#define Bndry_mask ((__uint32_t)0xfffffL)
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#define Bndry_mask1 ((__uint32_t)0xfffffL)
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#define LSB 1
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#define Sign_bit ((__uint32_t)0x80000000L)
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#define Log2P 1
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#define Tiny0 0
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#define Tiny1 1
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#define Quick_max 14
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#define Int_max 14
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#define Infinite(x) (word0(x) == ((__uint32_t)0x7ff00000L)) /* sufficient test for here */
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#endif
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#else
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#undef Sudden_Underflow
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#define Sudden_Underflow
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#ifdef IBM
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#define Exp_shift 24
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#define Exp_shift1 24
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#define Exp_msk1 ((__uint32_t)0x1000000L)
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#define Exp_msk11 ((__uint32_t)0x1000000L)
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#define Exp_mask ((__uint32_t)0x7f000000L)
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#define P 14
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#define Bias 65
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#define Exp_1 ((__uint32_t)0x41000000L)
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#define Exp_11 ((__uint32_t)0x41000000L)
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#define Ebits 8 /* exponent has 7 bits, but 8 is the right value in b2d */
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#define Frac_mask ((__uint32_t)0xffffffL)
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#define Frac_mask1 ((__uint32_t)0xffffffL)
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#define Bletch 4
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#define Ten_pmax 22
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#define Bndry_mask ((__uint32_t)0xefffffL)
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#define Bndry_mask1 ((__uint32_t)0xffffffL)
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#define LSB 1
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#define Sign_bit ((__uint32_t)0x80000000L)
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#define Log2P 4
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#define Tiny0 ((__uint32_t)0x100000L)
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#define Tiny1 0
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#define Quick_max 14
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#define Int_max 15
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#else /* VAX */
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#define Exp_shift 23
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#define Exp_shift1 7
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#define Exp_msk1 0x80
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#define Exp_msk11 ((__uint32_t)0x800000L)
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#define Exp_mask ((__uint32_t)0x7f80L)
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#define P 56
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#define Bias 129
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#define Exp_1 ((__uint32_t)0x40800000L)
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#define Exp_11 ((__uint32_t)0x4080L)
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#define Ebits 8
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#define Frac_mask ((__uint32_t)0x7fffffL)
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#define Frac_mask1 ((__uint32_t)0xffff007fL)
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#define Ten_pmax 24
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#define Bletch 2
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#define Bndry_mask ((__uint32_t)0xffff007fL)
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#define Bndry_mask1 ((__uint32_t)0xffff007fL)
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#define LSB ((__uint32_t)0x10000L)
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#define Sign_bit ((__uint32_t)0x8000L)
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#define Log2P 1
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#define Tiny0 0x80
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#define Tiny1 0
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#define Quick_max 15
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#define Int_max 15
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#endif
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#endif
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