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			389 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			389 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Software floating-point emulation.
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|    Definitions for IEEE Extended Precision.
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|    Copyright (C) 1999 Free Software Foundation, Inc.
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|    This file is part of the GNU C Library.
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|    Contributed by Jakub Jelinek (jj@ultra.linux.cz).
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| 
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|    The GNU C Library is free software; you can redistribute it and/or
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|    modify it under the terms of the GNU Lesser General Public
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|    License as published by the Free Software Foundation; either
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|    version 2.1 of the License, or (at your option) any later version.
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| 
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|    The GNU C Library is distributed in the hope that it will be useful,
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|    but 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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|    Lesser General Public License for more details.
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| 
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|    You should have received a copy of the GNU Lesser General Public
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|    License along with the GNU C Library; if not, write to the Free
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|    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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|    02111-1307 USA.  */
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| 
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| #if _FP_W_TYPE_SIZE < 32
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| #error "Here's a nickel, kid. Go buy yourself a real computer."
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| #endif
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| 
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| #if _FP_W_TYPE_SIZE < 64
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| #define _FP_FRACTBITS_E         (4*_FP_W_TYPE_SIZE)
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| #else
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| #define _FP_FRACTBITS_E		(2*_FP_W_TYPE_SIZE)
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| #endif
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| 
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| #define _FP_FRACBITS_E		64
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| #define _FP_FRACXBITS_E		(_FP_FRACTBITS_E - _FP_FRACBITS_E)
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| #define _FP_WFRACBITS_E		(_FP_WORKBITS + _FP_FRACBITS_E)
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| #define _FP_WFRACXBITS_E	(_FP_FRACTBITS_E - _FP_WFRACBITS_E)
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| #define _FP_EXPBITS_E		15
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| #define _FP_EXPBIAS_E		16383
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| #define _FP_EXPMAX_E		32767
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| 
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| #define _FP_QNANBIT_E		\
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| 	((_FP_W_TYPE)1 << (_FP_FRACBITS_E-2) % _FP_W_TYPE_SIZE)
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| #define _FP_IMPLBIT_E		\
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| 	((_FP_W_TYPE)1 << (_FP_FRACBITS_E-1) % _FP_W_TYPE_SIZE)
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| #define _FP_OVERFLOW_E		\
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| 	((_FP_W_TYPE)1 << (_FP_WFRACBITS_E % _FP_W_TYPE_SIZE))
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| 
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| #if _FP_W_TYPE_SIZE < 64
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| 
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| union _FP_UNION_E
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| {
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|    long double flt;
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|    struct 
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|    {
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| #if __BYTE_ORDER == __BIG_ENDIAN
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|       unsigned long pad1 : _FP_W_TYPE_SIZE;
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|       unsigned long pad2 : (_FP_W_TYPE_SIZE - 1 - _FP_EXPBITS_E);
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|       unsigned long sign : 1;
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|       unsigned long exp : _FP_EXPBITS_E;
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|       unsigned long frac1 : _FP_W_TYPE_SIZE;
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|       unsigned long frac0 : _FP_W_TYPE_SIZE;
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| #else
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|       unsigned long frac0 : _FP_W_TYPE_SIZE;
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|       unsigned long frac1 : _FP_W_TYPE_SIZE;
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|       unsigned exp : _FP_EXPBITS_E;
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|       unsigned sign : 1;
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| #endif /* not bigendian */
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|    } bits __attribute__((packed));
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| };
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| 
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| 
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| #define FP_DECL_E(X)		_FP_DECL(4,X)
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| 
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| #define FP_UNPACK_RAW_E(X, val)				\
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|   do {							\
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|     union _FP_UNION_E _flo; _flo.flt = (val);		\
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| 							\
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|     X##_f[2] = 0; X##_f[3] = 0;				\
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|     X##_f[0] = _flo.bits.frac0;				\
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|     X##_f[1] = _flo.bits.frac1;				\
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|     X##_e  = _flo.bits.exp;				\
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|     X##_s  = _flo.bits.sign;				\
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|     if (!X##_e && (X##_f[1] || X##_f[0])		\
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|         && !(X##_f[1] & _FP_IMPLBIT_E))			\
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|       {							\
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|         X##_e++;					\
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|         FP_SET_EXCEPTION(FP_EX_DENORM);			\
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|       }							\
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|   } while (0)
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| 
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| #define FP_UNPACK_RAW_EP(X, val)			\
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|   do {							\
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|     union _FP_UNION_E *_flo =				\
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|     (union _FP_UNION_E *)(val);				\
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| 							\
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|     X##_f[2] = 0; X##_f[3] = 0;				\
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|     X##_f[0] = _flo->bits.frac0;			\
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|     X##_f[1] = _flo->bits.frac1;			\
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|     X##_e  = _flo->bits.exp;				\
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|     X##_s  = _flo->bits.sign;				\
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|     if (!X##_e && (X##_f[1] || X##_f[0])		\
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|         && !(X##_f[1] & _FP_IMPLBIT_E))			\
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|       {							\
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|         X##_e++;					\
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|         FP_SET_EXCEPTION(FP_EX_DENORM);			\
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|       }							\
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|   } while (0)
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| 
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| #define FP_PACK_RAW_E(val, X)				\
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|   do {							\
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|     union _FP_UNION_E _flo;				\
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| 							\
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|     if (X##_e) X##_f[1] |= _FP_IMPLBIT_E;		\
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|     else X##_f[1] &= ~(_FP_IMPLBIT_E);			\
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|     _flo.bits.frac0 = X##_f[0];				\
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|     _flo.bits.frac1 = X##_f[1];				\
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|     _flo.bits.exp   = X##_e;				\
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|     _flo.bits.sign  = X##_s;				\
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| 							\
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|     (val) = _flo.flt;					\
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|   } while (0)
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| 
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| #define FP_PACK_RAW_EP(val, X)				\
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|   do {							\
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|     if (!FP_INHIBIT_RESULTS)				\
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|       {							\
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| 	union _FP_UNION_E *_flo =			\
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| 	  (union _FP_UNION_E *)(val);			\
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| 							\
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| 	if (X##_e) X##_f[1] |= _FP_IMPLBIT_E;		\
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| 	else X##_f[1] &= ~(_FP_IMPLBIT_E);		\
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| 	_flo->bits.frac0 = X##_f[0];			\
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| 	_flo->bits.frac1 = X##_f[1];			\
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| 	_flo->bits.exp   = X##_e;			\
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| 	_flo->bits.sign  = X##_s;			\
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|       }							\
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|   } while (0)
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| 
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| #define FP_UNPACK_E(X,val)		\
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|   do {					\
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|     FP_UNPACK_RAW_E(X,val);		\
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|     _FP_UNPACK_CANONICAL(E,4,X);	\
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|   } while (0)
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| 
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| #define FP_UNPACK_EP(X,val)		\
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|   do {					\
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|     FP_UNPACK_RAW_2_P(X,val);		\
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|     _FP_UNPACK_CANONICAL(E,4,X);	\
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|   } while (0)
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| 
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| #define FP_PACK_E(val,X)		\
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|   do {					\
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|     _FP_PACK_CANONICAL(E,4,X);		\
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|     FP_PACK_RAW_E(val,X);		\
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|   } while (0)
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| 
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| #define FP_PACK_EP(val,X)		\
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|   do {					\
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|     _FP_PACK_CANONICAL(E,4,X);		\
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|     FP_PACK_RAW_EP(val,X);		\
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|   } while (0)
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| 
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| #define FP_ISSIGNAN_E(X)	_FP_ISSIGNAN(E,4,X)
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| #define FP_NEG_E(R,X)		_FP_NEG(E,4,R,X)
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| #define FP_ADD_E(R,X,Y)		_FP_ADD(E,4,R,X,Y)
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| #define FP_SUB_E(R,X,Y)		_FP_SUB(E,4,R,X,Y)
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| #define FP_MUL_E(R,X,Y)		_FP_MUL(E,4,R,X,Y)
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| #define FP_DIV_E(R,X,Y)		_FP_DIV(E,4,R,X,Y)
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| #define FP_SQRT_E(R,X)		_FP_SQRT(E,4,R,X)
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| 
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| /*
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|  * Square root algorithms:
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|  * We have just one right now, maybe Newton approximation
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|  * should be added for those machines where division is fast.
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|  * This has special _E version because standard _4 square
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|  * root would not work (it has to start normally with the
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|  * second word and not the first), but as we have to do it
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|  * anyway, we optimize it by doing most of the calculations
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|  * in two UWtype registers instead of four.
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|  */
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|  
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| #define _FP_SQRT_MEAT_E(R, S, T, X, q)			\
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|   do {							\
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|     q = (_FP_W_TYPE)1 << (_FP_W_TYPE_SIZE - 1);		\
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|     _FP_FRAC_SRL_4(X, (_FP_WORKBITS));			\
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|     while (q)						\
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|       {							\
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| 	T##_f[1] = S##_f[1] + q;			\
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| 	if (T##_f[1] <= X##_f[1])			\
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| 	  {						\
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| 	    S##_f[1] = T##_f[1] + q;			\
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| 	    X##_f[1] -= T##_f[1];			\
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| 	    R##_f[1] += q;				\
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| 	  }						\
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| 	_FP_FRAC_SLL_2(X, 1);				\
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| 	q >>= 1;					\
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|       }							\
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|     q = (_FP_W_TYPE)1 << (_FP_W_TYPE_SIZE - 1);		\
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|     while (q)						\
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|       {							\
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| 	T##_f[0] = S##_f[0] + q;			\
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| 	T##_f[1] = S##_f[1];				\
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| 	if (T##_f[1] < X##_f[1] || 			\
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| 	    (T##_f[1] == X##_f[1] &&			\
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| 	     T##_f[0] <= X##_f[0]))			\
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| 	  {						\
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| 	    S##_f[0] = T##_f[0] + q;			\
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| 	    S##_f[1] += (T##_f[0] > S##_f[0]);		\
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| 	    _FP_FRAC_DEC_2(X, T);			\
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| 	    R##_f[0] += q;				\
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| 	  }						\
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| 	_FP_FRAC_SLL_2(X, 1);				\
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| 	q >>= 1;					\
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|       }							\
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|     _FP_FRAC_SLL_4(R, (_FP_WORKBITS));			\
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|     if (X##_f[0] | X##_f[1])				\
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|       {							\
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| 	if (S##_f[1] < X##_f[1] || 			\
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| 	    (S##_f[1] == X##_f[1] &&			\
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| 	     S##_f[0] < X##_f[0]))			\
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| 	  R##_f[0] |= _FP_WORK_ROUND;			\
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| 	R##_f[0] |= _FP_WORK_STICKY;			\
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|       }							\
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|   } while (0)
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| 
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| #define FP_CMP_E(r,X,Y,un)	_FP_CMP(E,4,r,X,Y,un)
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| #define FP_CMP_EQ_E(r,X,Y)	_FP_CMP_EQ(E,4,r,X,Y)
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| 
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| #define FP_TO_INT_E(r,X,rsz,rsg)	_FP_TO_INT(E,4,r,X,rsz,rsg)
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| #define FP_FROM_INT_E(X,r,rs,rt)	_FP_FROM_INT(E,4,X,r,rs,rt)
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| 
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| #define _FP_FRAC_HIGH_E(X)	(X##_f[2])
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| #define _FP_FRAC_HIGH_RAW_E(X)	(X##_f[1])
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| 
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| #else   /* not _FP_W_TYPE_SIZE < 64 */
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| union _FP_UNION_E
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| {
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|   long double flt /* __attribute__((mode(TF))) */ ;
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|   struct {
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| #if __BYTE_ORDER == __BIG_ENDIAN
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|     unsigned long pad : (_FP_W_TYPE_SIZE - 1 - _FP_EXPBITS_E);
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|     unsigned sign  : 1;
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|     unsigned exp   : _FP_EXPBITS_E;
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|     unsigned long frac : _FP_W_TYPE_SIZE;
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| #else
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|     unsigned long frac : _FP_W_TYPE_SIZE;
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|     unsigned exp   : _FP_EXPBITS_E;
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|     unsigned sign  : 1;
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| #endif
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|   } bits;
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| };
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| 
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| #define FP_DECL_E(X)		_FP_DECL(2,X)
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| 
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| #define FP_UNPACK_RAW_E(X, val)					\
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|   do {								\
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|     union _FP_UNION_E _flo; _flo.flt = (val);			\
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| 								\
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|     X##_f0 = _flo.bits.frac;					\
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|     X##_f1 = 0;							\
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|     X##_e = _flo.bits.exp;					\
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|     X##_s = _flo.bits.sign;					\
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|     if (!X##_e && X##_f0 && !(X##_f0 & _FP_IMPLBIT_E))		\
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|       {								\
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|         X##_e++;						\
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|         FP_SET_EXCEPTION(FP_EX_DENORM);				\
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|       }								\
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|   } while (0)
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| 
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| #define FP_UNPACK_RAW_EP(X, val)				\
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|   do {								\
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|     union _FP_UNION_E *_flo =					\
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|       (union _FP_UNION_E *)(val);				\
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| 								\
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|     X##_f0 = _flo->bits.frac;					\
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|     X##_f1 = 0;							\
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|     X##_e = _flo->bits.exp;					\
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|     X##_s = _flo->bits.sign;					\
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|     if (!X##_e && X##_f0 && !(X##_f0 & _FP_IMPLBIT_E))		\
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|       {								\
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|         X##_e++;						\
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|         FP_SET_EXCEPTION(FP_EX_DENORM);				\
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|       }								\
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|   } while (0)
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| 
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| #define FP_PACK_RAW_E(val, X)					\
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|   do {								\
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|     union _FP_UNION_E _flo;					\
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| 								\
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|     if (X##_e) X##_f0 |= _FP_IMPLBIT_E;				\
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|     else X##_f0 &= ~(_FP_IMPLBIT_E);				\
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|     _flo.bits.frac = X##_f0;					\
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|     _flo.bits.exp  = X##_e;					\
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|     _flo.bits.sign = X##_s;					\
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| 								\
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|     (val) = _flo.flt;						\
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|   } while (0)
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| 
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| #define FP_PACK_RAW_EP(fs, val, X)				\
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|   do {								\
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|     if (!FP_INHIBIT_RESULTS)					\
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|       {								\
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| 	union _FP_UNION_E *_flo =				\
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| 	  (union _FP_UNION_E *)(val);				\
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| 								\
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| 	if (X##_e) X##_f0 |= _FP_IMPLBIT_E;			\
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| 	else X##_f0 &= ~(_FP_IMPLBIT_E);			\
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| 	_flo->bits.frac = X##_f0;				\
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| 	_flo->bits.exp  = X##_e;				\
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| 	_flo->bits.sign = X##_s;				\
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|       }								\
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|   } while (0)
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| 
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| 
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| #define FP_UNPACK_E(X,val)		\
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|   do {					\
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|     FP_UNPACK_RAW_E(X,val);		\
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|     _FP_UNPACK_CANONICAL(E,2,X);	\
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|   } while (0)
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| 
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| #define FP_UNPACK_EP(X,val)		\
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|   do {					\
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|     FP_UNPACK_RAW_EP(X,val);		\
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|     _FP_UNPACK_CANONICAL(E,2,X);	\
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|   } while (0)
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| 
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| #define FP_PACK_E(val,X)		\
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|   do {					\
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|     _FP_PACK_CANONICAL(E,2,X);		\
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|     FP_PACK_RAW_E(val,X);		\
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|   } while (0)
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| 
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| #define FP_PACK_EP(val,X)		\
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|   do {					\
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|     _FP_PACK_CANONICAL(E,2,X);		\
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|     FP_PACK_RAW_EP(val,X);		\
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|   } while (0)
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| 
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| #define FP_ISSIGNAN_E(X)	_FP_ISSIGNAN(E,2,X)
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| #define FP_NEG_E(R,X)		_FP_NEG(E,2,R,X)
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| #define FP_ADD_E(R,X,Y)		_FP_ADD(E,2,R,X,Y)
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| #define FP_SUB_E(R,X,Y)		_FP_SUB(E,2,R,X,Y)
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| #define FP_MUL_E(R,X,Y)		_FP_MUL(E,2,R,X,Y)
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| #define FP_DIV_E(R,X,Y)		_FP_DIV(E,2,R,X,Y)
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| #define FP_SQRT_E(R,X)		_FP_SQRT(E,2,R,X)
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| 
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| /*
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|  * Square root algorithms:
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|  * We have just one right now, maybe Newton approximation
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|  * should be added for those machines where division is fast.
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|  * We optimize it by doing most of the calculations
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|  * in one UWtype registers instead of two, although we don't
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|  * have to.
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|  */
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| #define _FP_SQRT_MEAT_E(R, S, T, X, q)			\
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|   do {							\
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|     q = (_FP_W_TYPE)1 << (_FP_W_TYPE_SIZE - 1);		\
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|     _FP_FRAC_SRL_2(X, (_FP_WORKBITS));			\
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|     while (q)						\
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|       {							\
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|         T##_f0 = S##_f0 + q;				\
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|         if (T##_f0 <= X##_f0)				\
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|           {						\
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|             S##_f0 = T##_f0 + q;			\
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|             X##_f0 -= T##_f0;				\
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|             R##_f0 += q;				\
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|           }						\
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|         _FP_FRAC_SLL_1(X, 1);				\
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|         q >>= 1;					\
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|       }							\
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|     _FP_FRAC_SLL_2(R, (_FP_WORKBITS));			\
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|     if (X##_f0)						\
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|       {							\
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| 	if (S##_f0 < X##_f0)				\
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| 	  R##_f0 |= _FP_WORK_ROUND;			\
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| 	R##_f0 |= _FP_WORK_STICKY;			\
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|       }							\
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|   } while (0)
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|  
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| #define FP_CMP_E(r,X,Y,un)	_FP_CMP(E,2,r,X,Y,un)
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| #define FP_CMP_EQ_E(r,X,Y)	_FP_CMP_EQ(E,2,r,X,Y)
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| 
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| #define FP_TO_INT_E(r,X,rsz,rsg)	_FP_TO_INT(E,2,r,X,rsz,rsg)
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| #define FP_FROM_INT_E(X,r,rs,rt)	_FP_FROM_INT(E,2,X,r,rs,rt)
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| 
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| #define _FP_FRAC_HIGH_E(X)	(X##_f1)
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| #define _FP_FRAC_HIGH_RAW_E(X)	(X##_f0)
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| 
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| #endif /* not _FP_W_TYPE_SIZE < 64 */
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