sgl_float.h

这个linux源代码是很全面的~基本完整了~使用c编译的~由于时间问题我没有亲自测试~但就算用来做参考资料也是非常好的

/*
 * Linux/PA-RISC Project (http://www.parisc-linux.org/)
 *
 * Floating-point emulation code
 *  Copyright (C) 2001 Hewlett-Packard (Paul Bame) <[e-mail]>
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2, or (at your option)
 *    any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#ifdef __NO_PA_HDRS
    PA header file -- do not include this header file for non-PA builds.
#endif

/* 32-bit word grabing functions */
#define Sgl_firstword(value) Sall(value)
#define Sgl_secondword(value) dummy_location
#define Sgl_thirdword(value) dummy_location
#define Sgl_fourthword(value) dummy_location

#define Sgl_sign(object) Ssign(object)
#define Sgl_exponent(object) Sexponent(object)
#define Sgl_signexponent(object) Ssignexponent(object)
#define Sgl_mantissa(object) Smantissa(object)
#define Sgl_exponentmantissa(object) Sexponentmantissa(object)
#define Sgl_all(object) Sall(object)

/* sgl_and_signs ands the sign bits of each argument and puts the result
 * into the first argument. sgl_or_signs ors those same sign bits */
#define Sgl_and_signs( src1dst, src2)		\
    Sall(src1dst) = (Sall(src2)|~((unsigned int)1<<31)) & Sall(src1dst)
#define Sgl_or_signs( src1dst, src2)		\
    Sall(src1dst) = (Sall(src2)&((unsigned int)1<<31)) | Sall(src1dst)

/* The hidden bit is always the low bit of the exponent */
#define Sgl_clear_exponent_set_hidden(srcdst) Deposit_sexponent(srcdst,1)
#define Sgl_clear_signexponent_set_hidden(srcdst) \
    Deposit_ssignexponent(srcdst,1)
#define Sgl_clear_sign(srcdst) Sall(srcdst) &= ~((unsigned int)1<<31)
#define Sgl_clear_signexponent(srcdst) Sall(srcdst) &= 0x007fffff

/* varamount must be less than 32 for the next three functions */
#define Sgl_rightshift(srcdst, varamount)	\
    Sall(srcdst) >>= varamount
#define Sgl_leftshift(srcdst, varamount)	\
    Sall(srcdst) <<= varamount
#define Sgl_rightshift_exponentmantissa(srcdst, varamount) \
    Sall(srcdst) = \
	(Sexponentmantissa(srcdst) >> varamount) | \
	(Sall(srcdst) & ((unsigned int)1<<31))

#define Sgl_leftshiftby1_withextent(left,right,result) \
    Shiftdouble(Sall(left),Extall(right),31,Sall(result))
    
#define Sgl_rightshiftby1_withextent(left,right,dst)		\
    Shiftdouble(Sall(left),Extall(right),1,Extall(right))
#define Sgl_arithrightshiftby1(srcdst)	\
    Sall(srcdst) = (int)Sall(srcdst) >> 1
    
/* Sign extend the sign bit with an integer destination */
#define Sgl_signextendedsign(value) Ssignedsign(value)

#define Sgl_isone_hidden(sgl_value) (Shidden(sgl_value))
#define Sgl_increment(sgl_value) Sall(sgl_value) += 1
#define Sgl_increment_mantissa(sgl_value) \
    Deposit_smantissa(sgl_value,sgl_value+1)
#define Sgl_decrement(sgl_value) Sall(sgl_value) -= 1

#define Sgl_isone_sign(sgl_value) (Is_ssign(sgl_value)!=0)
#define Sgl_isone_hiddenoverflow(sgl_value) \
    (Is_shiddenoverflow(sgl_value)!=0)
#define Sgl_isone_lowmantissa(sgl_value) (Is_slow(sgl_value)!=0)
#define Sgl_isone_signaling(sgl_value) (Is_ssignaling(sgl_value)!=0)
#define Sgl_is_signalingnan(sgl_value) (Ssignalingnan(sgl_value)==0x1ff)
#define Sgl_isnotzero(sgl_value) (Sall(sgl_value)!=0)
#define Sgl_isnotzero_hiddenhigh7mantissa(sgl_value) \
    (Shiddenhigh7mantissa(sgl_value)!=0)
#define Sgl_isnotzero_low4(sgl_value) (Slow4(sgl_value)!=0)
#define Sgl_isnotzero_exponent(sgl_value) (Sexponent(sgl_value)!=0)
#define Sgl_isnotzero_mantissa(sgl_value) (Smantissa(sgl_value)!=0)
#define Sgl_isnotzero_exponentmantissa(sgl_value) \
    (Sexponentmantissa(sgl_value)!=0)
#define Sgl_iszero(sgl_value) (Sall(sgl_value)==0)
#define Sgl_iszero_signaling(sgl_value) (Is_ssignaling(sgl_value)==0)
#define Sgl_iszero_hidden(sgl_value) (Is_shidden(sgl_value)==0)
#define Sgl_iszero_hiddenoverflow(sgl_value) \
    (Is_shiddenoverflow(sgl_value)==0)
#define Sgl_iszero_hiddenhigh3mantissa(sgl_value) \
    (Shiddenhigh3mantissa(sgl_value)==0)
#define Sgl_iszero_hiddenhigh7mantissa(sgl_value) \
    (Shiddenhigh7mantissa(sgl_value)==0)
#define Sgl_iszero_sign(sgl_value) (Is_ssign(sgl_value)==0)
#define Sgl_iszero_exponent(sgl_value) (Sexponent(sgl_value)==0)
#define Sgl_iszero_mantissa(sgl_value) (Smantissa(sgl_value)==0)
#define Sgl_iszero_exponentmantissa(sgl_value) \
    (Sexponentmantissa(sgl_value)==0)
#define Sgl_isinfinity_exponent(sgl_value) 		\
    (Sgl_exponent(sgl_value)==SGL_INFINITY_EXPONENT)
#define Sgl_isnotinfinity_exponent(sgl_value) 		\
    (Sgl_exponent(sgl_value)!=SGL_INFINITY_EXPONENT)
#define Sgl_isinfinity(sgl_value)			\
    (Sgl_exponent(sgl_value)==SGL_INFINITY_EXPONENT &&	\
    Sgl_mantissa(sgl_value)==0)
#define Sgl_isnan(sgl_value)				\
    (Sgl_exponent(sgl_value)==SGL_INFINITY_EXPONENT &&	\
    Sgl_mantissa(sgl_value)!=0)
#define Sgl_isnotnan(sgl_value)				\
    (Sgl_exponent(sgl_value)!=SGL_INFINITY_EXPONENT ||	\
    Sgl_mantissa(sgl_value)==0)
#define Sgl_islessthan(sgl_op1,sgl_op2)			\
    (Sall(sgl_op1) < Sall(sgl_op2))
#define Sgl_isgreaterthan(sgl_op1,sgl_op2)		\
    (Sall(sgl_op1) > Sall(sgl_op2))
#define Sgl_isnotlessthan(sgl_op1,sgl_op2)		\
    (Sall(sgl_op1) >= Sall(sgl_op2))
#define Sgl_isequal(sgl_op1,sgl_op2)			\
    (Sall(sgl_op1) == Sall(sgl_op2))

#define Sgl_leftshiftby8(sgl_value) \
    Sall(sgl_value) <<= 8
#define Sgl_leftshiftby4(sgl_value) \
    Sall(sgl_value) <<= 4
#define Sgl_leftshiftby3(sgl_value) \
    Sall(sgl_value) <<= 3
#define Sgl_leftshiftby2(sgl_value) \
    Sall(sgl_value) <<= 2
#define Sgl_leftshiftby1(sgl_value) \
    Sall(sgl_value) <<= 1
#define Sgl_rightshiftby1(sgl_value) \
    Sall(sgl_value) >>= 1
#define Sgl_rightshiftby4(sgl_value) \
    Sall(sgl_value) >>= 4
#define Sgl_rightshiftby8(sgl_value) \
    Sall(sgl_value) >>= 8
    
#define Sgl_ismagnitudeless(signlessleft,signlessright)			\
/*  unsigned int signlessleft, signlessright; */			\
      (signlessleft < signlessright)  
    

#define Sgl_copytoint_exponentmantissa(source,dest)     \
    dest = Sexponentmantissa(source)

/* A quiet NaN has the high mantissa bit clear and at least on other (in this
 * case the adjacent bit) bit set. */
#define Sgl_set_quiet(sgl_value) Deposit_shigh2mantissa(sgl_value,1)
#define Sgl_set_exponent(sgl_value,exp) Deposit_sexponent(sgl_value,exp)

#define Sgl_set_mantissa(dest,value) Deposit_smantissa(dest,value)
#define Sgl_set_exponentmantissa(dest,value) \
    Deposit_sexponentmantissa(dest,value)

/*  An infinity is represented with the max exponent and a zero mantissa */
#define Sgl_setinfinity_exponent(sgl_value) \
    Deposit_sexponent(sgl_value,SGL_INFINITY_EXPONENT)
#define Sgl_setinfinity_exponentmantissa(sgl_value)	\
    Deposit_sexponentmantissa(sgl_value, \
	(SGL_INFINITY_EXPONENT << (32-(1+SGL_EXP_LENGTH))))
#define Sgl_setinfinitypositive(sgl_value)		\
    Sall(sgl_value) = (SGL_INFINITY_EXPONENT << (32-(1+SGL_EXP_LENGTH)))
#define Sgl_setinfinitynegative(sgl_value)		\
    Sall(sgl_value) = (SGL_INFINITY_EXPONENT << (32-(1+SGL_EXP_LENGTH))) \
    | ((unsigned int)1<<31)
#define Sgl_setinfinity(sgl_value,sign)					\
    Sall(sgl_value) = (SGL_INFINITY_EXPONENT << (32-(1+SGL_EXP_LENGTH))) | \
     ((unsigned int)sign << 31)
#define Sgl_sethigh4bits(sgl_value, extsign)  \
    Deposit_shigh4(sgl_value,extsign)
#define Sgl_set_sign(sgl_value,sign) Deposit_ssign(sgl_value,sign)
#define Sgl_invert_sign(sgl_value)  \
    Deposit_ssign(sgl_value,~Ssign(sgl_value))
#define Sgl_setone_sign(sgl_value) Deposit_ssign(sgl_value,1)
#define Sgl_setone_lowmantissa(sgl_value) Deposit_slow(sgl_value,1)
#define Sgl_setzero_sign(sgl_value)  Sall(sgl_value) &= 0x7fffffff
#define Sgl_setzero_exponent(sgl_value) Sall(sgl_value) &= 0x807fffff
#define Sgl_setzero_mantissa(sgl_value) Sall(sgl_value) &= 0xff800000
#define Sgl_setzero_exponentmantissa(sgl_value)  Sall(sgl_value) &= 0x80000000
#define Sgl_setzero(sgl_value) Sall(sgl_value) = 0
#define Sgl_setnegativezero(sgl_value) Sall(sgl_value) = (unsigned int)1 << 31

/* Use following macro for both overflow & underflow conditions */
#define ovfl -
#define unfl +
#define Sgl_setwrapped_exponent(sgl_value,exponent,op) \
    Deposit_sexponent(sgl_value,(exponent op SGL_WRAP))

#define Sgl_setlargestpositive(sgl_value) 				\
    Sall(sgl_value) = ((SGL_EMAX+SGL_BIAS) << (32-(1+SGL_EXP_LENGTH)))	\
                      | ((1<<(32-(1+SGL_EXP_LENGTH))) - 1 )
#define Sgl_setlargestnegative(sgl_value)				\
    Sall(sgl_value) = ((SGL_EMAX+SGL_BIAS) << (32-(1+SGL_EXP_LENGTH)))	\
                      | ((1<<(32-(1+SGL_EXP_LENGTH))) - 1 )		\
		      | ((unsigned int)1<<31)

#define Sgl_setnegativeinfinity(sgl_value)	\
    Sall(sgl_value) = 				\
    ((1<<SGL_EXP_LENGTH) | SGL_INFINITY_EXPONENT) << (32-(1+SGL_EXP_LENGTH))
#define Sgl_setlargest(sgl_value,sign) 					\
    Sall(sgl_value) = (unsigned int)sign << 31 |			\
        (((SGL_EMAX+SGL_BIAS) << (32-(1+SGL_EXP_LENGTH)))		\
	  | ((1 << (32-(1+SGL_EXP_LENGTH))) - 1 ))
#define Sgl_setlargest_exponentmantissa(sgl_value)			\
    Sall(sgl_value) = Sall(sgl_value) & ((unsigned int)1<<31) |		\
        (((SGL_EMAX+SGL_BIAS) << (32-(1+SGL_EXP_LENGTH)))		\
	  | ((1 << (32-(1+SGL_EXP_LENGTH))) - 1 ))

/* The high bit is always zero so arithmetic or logical shifts will work. */
#define Sgl_right_align(srcdst,shift,extent)				\
    /* sgl_floating_point srcdst; int shift; extension extent */	\
    if (shift < 32) {							\
	Extall(extent) = Sall(srcdst) << (32-(shift));			\
    	Sall(srcdst) >>= shift;						\
    }									\
    else {								\
	Extall(extent) = Sall(srcdst);					\
	Sall(srcdst) = 0;						\
    }
#define Sgl_hiddenhigh3mantissa(sgl_value) Shiddenhigh3mantissa(sgl_value)
#define Sgl_hidden(sgl_value) Shidden(sgl_value)
#define Sgl_lowmantissa(sgl_value) Slow(sgl_value)

/* The left argument is never smaller than the right argument */
#define Sgl_subtract(sgl_left,sgl_right,sgl_result) \
    Sall(sgl_result) = Sall(sgl_left) - Sall(sgl_right)

/* Subtract right augmented with extension from left augmented with zeros and
 * store into result and extension. */
#define Sgl_subtract_withextension(left,right,extent,result)		\
    /* sgl_floating_point left,right,result; extension extent */	\
  Sgl_subtract(left,right,result);					\
  if((Extall(extent) = 0-Extall(extent)))				\
      Sall(result) = Sall(result)-1