285 lines
		
	
	
		
			7.1 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			285 lines
		
	
	
		
			7.1 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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| 
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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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| 
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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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| 
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| #include <newlib.h>
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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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| #include <sys/cdefs.h>
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| 
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| #ifdef __IEEE_LITTLE_ENDIAN
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| #define IEEE_8087
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| #endif
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| 
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| #ifdef __IEEE_BIG_ENDIAN
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| #define IEEE_MC68k
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| #endif
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| 
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| #ifdef __Z8000__
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| #define Just_16
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| #endif
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| 
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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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| 
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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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| 
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| #ifdef _WANT_IO_LONG_DOUBLE
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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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| 
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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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| } __packed;
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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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| } __packed;
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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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| } __packed;
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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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| } __packed;
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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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| } __packed;
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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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| } __packed;
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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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| } __packed;
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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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| } __packed;
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| #endif /* LDBL_MANT_DIG */
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| #endif /* !IEEE_8087 */
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| #endif /* _WANT_IO_LONG_DOUBLE */
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| 
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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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| 
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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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| 
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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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| 
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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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| #define IEEE_Arith
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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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| 
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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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| 
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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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| 
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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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| 
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| 
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