dbl_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 Dbl_firstword(value) Dallp1(value)
#define Dbl_secondword(value) Dallp2(value)
#define Dbl_thirdword(value) dummy_location
#define Dbl_fourthword(value) dummy_location

#define Dbl_sign(object) Dsign(object)
#define Dbl_exponent(object) Dexponent(object)
#define Dbl_signexponent(object) Dsignexponent(object)
#define Dbl_mantissap1(object) Dmantissap1(object)
#define Dbl_mantissap2(object) Dmantissap2(object)
#define Dbl_exponentmantissap1(object) Dexponentmantissap1(object)
#define Dbl_allp1(object) Dallp1(object)
#define Dbl_allp2(object) Dallp2(object)

/* dbl_and_signs ands the sign bits of each argument and puts the result
 * into the first argument. dbl_or_signs ors those same sign bits */
#define Dbl_and_signs( src1dst, src2)		\
    Dallp1(src1dst) = (Dallp1(src2)|~((unsigned int)1<<31)) & Dallp1(src1dst)
#define Dbl_or_signs( src1dst, src2)		\
    Dallp1(src1dst) = (Dallp1(src2)&((unsigned int)1<<31)) | Dallp1(src1dst)

/* The hidden bit is always the low bit of the exponent */
#define Dbl_clear_exponent_set_hidden(srcdst) Deposit_dexponent(srcdst,1)
#define Dbl_clear_signexponent_set_hidden(srcdst) \
    Deposit_dsignexponent(srcdst,1)
#define Dbl_clear_sign(srcdst) Dallp1(srcdst) &= ~((unsigned int)1<<31)
#define Dbl_clear_signexponent(srcdst) \
    Dallp1(srcdst) &= Dmantissap1((unsigned int)-1)

/* Exponent field for doubles has already been cleared and may be
 * included in the shift.  Here we need to generate two double width
 * variable shifts.  The insignificant bits can be ignored.
 *      MTSAR f(varamount)
 *      VSHD	srcdst.high,srcdst.low => srcdst.low
 *	VSHD	0,srcdst.high => srcdst.high 
 * This is very difficult to model with C expressions since the shift amount
 * could exceed 32.  */
/* varamount must be less than 64 */
#define Dbl_rightshift(srcdstA, srcdstB, varamount)			\
    {if((varamount) >= 32) {						\
        Dallp2(srcdstB) = Dallp1(srcdstA) >> (varamount-32);		\
        Dallp1(srcdstA)=0;						\
    }									\
    else if(varamount > 0) {						\
	Variable_shift_double(Dallp1(srcdstA), Dallp2(srcdstB), 	\
	  (varamount), Dallp2(srcdstB));				\
	Dallp1(srcdstA) >>= varamount;					\
    } }
/* varamount must be less than 64 */
#define Dbl_rightshift_exponentmantissa(srcdstA, srcdstB, varamount)	\
    {if((varamount) >= 32) {						\
        Dallp2(srcdstB) = Dexponentmantissap1(srcdstA) >> (varamount-32); \
	Dallp1(srcdstA) &= ((unsigned int)1<<31);  /* clear expmant field */ \
    }									\
    else if(varamount > 0) {						\
	Variable_shift_double(Dexponentmantissap1(srcdstA), Dallp2(srcdstB), \
	(varamount), Dallp2(srcdstB));					\
	Deposit_dexponentmantissap1(srcdstA,				\
	    (Dexponentmantissap1(srcdstA)>>varamount));			\
    } }
/* varamount must be less than 64 */
#define Dbl_leftshift(srcdstA, srcdstB, varamount)			\
    {if((varamount) >= 32) {						\
	Dallp1(srcdstA) = Dallp2(srcdstB) << (varamount-32);		\
	Dallp2(srcdstB)=0;						\
    }									\
    else {								\
	if ((varamount) > 0) {						\
	    Dallp1(srcdstA) = (Dallp1(srcdstA) << (varamount)) |	\
		(Dallp2(srcdstB) >> (32-(varamount)));			\
	    Dallp2(srcdstB) <<= varamount;				\
	}								\
    } }
#define Dbl_leftshiftby1_withextent(lefta,leftb,right,resulta,resultb)	\
    Shiftdouble(Dallp1(lefta), Dallp2(leftb), 31, Dallp1(resulta));	\
    Shiftdouble(Dallp2(leftb), Extall(right), 31, Dallp2(resultb)) 
    
#define Dbl_rightshiftby1_withextent(leftb,right,dst)		\
    Extall(dst) = (Dallp2(leftb) << 31) | ((unsigned int)Extall(right) >> 1) | \
		  Extlow(right)

#define Dbl_arithrightshiftby1(srcdstA,srcdstB)			\
    Shiftdouble(Dallp1(srcdstA),Dallp2(srcdstB),1,Dallp2(srcdstB));\
    Dallp1(srcdstA) = (int)Dallp1(srcdstA) >> 1
   
/* Sign extend the sign bit with an integer destination */
#define Dbl_signextendedsign(value)  Dsignedsign(value)

#define Dbl_isone_hidden(dbl_value) (Is_dhidden(dbl_value)!=0)
/* Singles and doubles may include the sign and exponent fields.  The
 * hidden bit and the hidden overflow must be included. */
#define Dbl_increment(dbl_valueA,dbl_valueB) \
    if( (Dallp2(dbl_valueB) += 1) == 0 )  Dallp1(dbl_valueA) += 1
#define Dbl_increment_mantissa(dbl_valueA,dbl_valueB) \
    if( (Dmantissap2(dbl_valueB) += 1) == 0 )  \
    Deposit_dmantissap1(dbl_valueA,dbl_valueA+1)
#define Dbl_decrement(dbl_valueA,dbl_valueB) \
    if( Dallp2(dbl_valueB) == 0 )  Dallp1(dbl_valueA) -= 1; \
    Dallp2(dbl_valueB) -= 1

#define Dbl_isone_sign(dbl_value) (Is_dsign(dbl_value)!=0)
#define Dbl_isone_hiddenoverflow(dbl_value) (Is_dhiddenoverflow(dbl_value)!=0)
#define Dbl_isone_lowmantissap1(dbl_valueA) (Is_dlowp1(dbl_valueA)!=0)
#define Dbl_isone_lowmantissap2(dbl_valueB) (Is_dlowp2(dbl_valueB)!=0)
#define Dbl_isone_signaling(dbl_value) (Is_dsignaling(dbl_value)!=0)
#define Dbl_is_signalingnan(dbl_value) (Dsignalingnan(dbl_value)==0xfff)
#define Dbl_isnotzero(dbl_valueA,dbl_valueB) \
    (Dallp1(dbl_valueA) || Dallp2(dbl_valueB))
#define Dbl_isnotzero_hiddenhigh7mantissa(dbl_value) \
    (Dhiddenhigh7mantissa(dbl_value)!=0)
#define Dbl_isnotzero_exponent(dbl_value) (Dexponent(dbl_value)!=0)
#define Dbl_isnotzero_mantissa(dbl_valueA,dbl_valueB) \
    (Dmantissap1(dbl_valueA) || Dmantissap2(dbl_valueB))
#define Dbl_isnotzero_mantissap1(dbl_valueA) (Dmantissap1(dbl_valueA)!=0)
#define Dbl_isnotzero_mantissap2(dbl_valueB) (Dmantissap2(dbl_valueB)!=0)
#define Dbl_isnotzero_exponentmantissa(dbl_valueA,dbl_valueB) \
    (Dexponentmantissap1(dbl_valueA) || Dmantissap2(dbl_valueB))
#define Dbl_isnotzero_low4p2(dbl_value) (Dlow4p2(dbl_value)!=0)
#define Dbl_iszero(dbl_valueA,dbl_valueB) (Dallp1(dbl_valueA)==0 && \
    Dallp2(dbl_valueB)==0)
#define Dbl_iszero_allp1(dbl_value) (Dallp1(dbl_value)==0)
#define Dbl_iszero_allp2(dbl_value) (Dallp2(dbl_value)==0)
#define Dbl_iszero_hidden(dbl_value) (Is_dhidden(dbl_value)==0)
#define Dbl_iszero_hiddenoverflow(dbl_value) (Is_dhiddenoverflow(dbl_value)==0)
#define Dbl_iszero_hiddenhigh3mantissa(dbl_value) \
    (Dhiddenhigh3mantissa(dbl_value)==0)
#define Dbl_iszero_hiddenhigh7mantissa(dbl_value) \
    (Dhiddenhigh7mantissa(dbl_value)==0)
#define Dbl_iszero_sign(dbl_value) (Is_dsign(dbl_value)==0)
#define Dbl_iszero_exponent(dbl_value) (Dexponent(dbl_value)==0)
#define Dbl_iszero_mantissa(dbl_valueA,dbl_valueB) \
    (Dmantissap1(dbl_valueA)==0 && Dmantissap2(dbl_valueB)==0)
#define Dbl_iszero_exponentmantissa(dbl_valueA,dbl_valueB) \
    (Dexponentmantissap1(dbl_valueA)==0 && Dmantissap2(dbl_valueB)==0)
#define Dbl_isinfinity_exponent(dbl_value)		\
    (Dexponent(dbl_value)==DBL_INFINITY_EXPONENT)
#define Dbl_isnotinfinity_exponent(dbl_value)		\
    (Dexponent(dbl_value)!=DBL_INFINITY_EXPONENT)
#define Dbl_isinfinity(dbl_valueA,dbl_valueB)			\
    (Dexponent(dbl_valueA)==DBL_INFINITY_EXPONENT &&	\
    Dmantissap1(dbl_valueA)==0 && Dmantissap2(dbl_valueB)==0)
#define Dbl_isnan(dbl_valueA,dbl_valueB)		\
    (Dexponent(dbl_valueA)==DBL_INFINITY_EXPONENT &&	\
    (Dmantissap1(dbl_valueA)!=0 || Dmantissap2(dbl_valueB)!=0))
#define Dbl_isnotnan(dbl_valueA,dbl_valueB)		\
    (Dexponent(dbl_valueA)!=DBL_INFINITY_EXPONENT ||	\
    (Dmantissap1(dbl_valueA)==0 && Dmantissap2(dbl_valueB)==0))

#define Dbl_islessthan(dbl_op1a,dbl_op1b,dbl_op2a,dbl_op2b)	\
    (Dallp1(dbl_op1a) < Dallp1(dbl_op2a) ||			\
     (Dallp1(dbl_op1a) == Dallp1(dbl_op2a) &&			\
      Dallp2(dbl_op1b) < Dallp2(dbl_op2b)))
#define Dbl_isgreaterthan(dbl_op1a,dbl_op1b,dbl_op2a,dbl_op2b)	\
    (Dallp1(dbl_op1a) > Dallp1(dbl_op2a) ||			\
     (Dallp1(dbl_op1a) == Dallp1(dbl_op2a) &&			\
      Dallp2(dbl_op1b) > Dallp2(dbl_op2b)))
#define Dbl_isnotlessthan(dbl_op1a,dbl_op1b,dbl_op2a,dbl_op2b)	\
    (Dallp1(dbl_op1a) > Dallp1(dbl_op2a) ||			\
     (Dallp1(dbl_op1a) == Dallp1(dbl_op2a) &&			\
      Dallp2(dbl_op1b) >= Dallp2(dbl_op2b)))
#define Dbl_isnotgreaterthan(dbl_op1a,dbl_op1b,dbl_op2a,dbl_op2b) \
    (Dallp1(dbl_op1a) < Dallp1(dbl_op2a) ||			\
     (Dallp1(dbl_op1a) == Dallp1(dbl_op2a) &&			\
      Dallp2(dbl_op1b) <= Dallp2(dbl_op2b)))
#define Dbl_isequal(dbl_op1a,dbl_op1b,dbl_op2a,dbl_op2b)	\
     ((Dallp1(dbl_op1a) == Dallp1(dbl_op2a)) &&			\
      (Dallp2(dbl_op1b) == Dallp2(dbl_op2b)))

#define Dbl_leftshiftby8(dbl_valueA,dbl_valueB) \
    Shiftdouble(Dallp1(dbl_valueA),Dallp2(dbl_valueB),24,Dallp1(dbl_valueA)); \
    Dallp2(dbl_valueB) <<= 8
#define Dbl_leftshiftby7(dbl_valueA,dbl_valueB) \
    Shiftdouble(Dallp1(dbl_valueA),Dallp2(dbl_valueB),25,Dallp1(dbl_valueA)); \
    Dallp2(dbl_valueB) <<= 7
#define Dbl_leftshiftby4(dbl_valueA,dbl_valueB) \
    Shiftdouble(Dallp1(dbl_valueA),Dallp2(dbl_valueB),28,Dallp1(dbl_valueA)); \
    Dallp2(dbl_valueB) <<= 4
#define Dbl_leftshiftby3(dbl_valueA,dbl_valueB) \
    Shiftdouble(Dallp1(dbl_valueA),Dallp2(dbl_valueB),29,Dallp1(dbl_valueA)); \
    Dallp2(dbl_valueB) <<= 3
#define Dbl_leftshiftby2(dbl_valueA,dbl_valueB) \
    Shiftdouble(Dallp1(dbl_valueA),Dallp2(dbl_valueB),30,Dallp1(dbl_valueA)); \
    Dallp2(dbl_valueB) <<= 2
#define Dbl_leftshiftby1(dbl_valueA,dbl_valueB) \
    Shiftdouble(Dallp1(dbl_valueA),Dallp2(dbl_valueB),31,Dallp1(dbl_valueA)); \
    Dallp2(dbl_valueB) <<= 1

#define Dbl_rightshiftby8(dbl_valueA,dbl_valueB) \
    Shiftdouble(Dallp1(dbl_valueA),Dallp2(dbl_valueB),8,Dallp2(dbl_valueB)); \
    Dallp1(dbl_valueA) >>= 8
#define Dbl_rightshiftby4(dbl_valueA,dbl_valueB) \
    Shiftdouble(Dallp1(dbl_valueA),Dallp2(dbl_valueB),4,Dallp2(dbl_valueB)); \
    Dallp1(dbl_valueA) >>= 4
#define Dbl_rightshiftby2(dbl_valueA,dbl_valueB) \
    Shiftdouble(Dallp1(dbl_valueA),Dallp2(dbl_valueB),2,Dallp2(dbl_valueB)); \
    Dallp1(dbl_valueA) >>= 2
#define Dbl_rightshiftby1(dbl_valueA,dbl_valueB) \
    Shiftdouble(Dallp1(dbl_valueA),Dallp2(dbl_valueB),1,Dallp2(dbl_valueB)); \
    Dallp1(dbl_valueA) >>= 1
    
/* This magnitude comparison uses the signless first words and
 * the regular part2 words.  The comparison is graphically:
 *
 *       1st greater?  -------------
 *                                 |
 *       1st less?-----------------+---------
 *                                 |        |
 *       2nd greater or equal----->|        |
 *                               False     True
 */
#define Dbl_ismagnitudeless(leftB,rightB,signlessleft,signlessright)	\
      ((signlessleft <= signlessright) &&				\
       ( (signlessleft < signlessright) || (Dallp2(leftB)<Dallp2(rightB)) ))
    
#define Dbl_copytoint_exponentmantissap1(src,dest) \
    dest = Dexponentmantissap1(src)

/* A quiet NaN has the high mantissa bit clear and at least on other (in this
 * case the adjacent bit) bit set. */
#define Dbl_set_quiet(dbl_value) Deposit_dhigh2mantissa(dbl_value,1)
#define Dbl_set_exponent(dbl_value, exp) Deposit_dexponent(dbl_value,exp)

#define Dbl_set_mantissa(desta,destb,valuea,valueb)	\
    Deposit_dmantissap1(desta,valuea);			\
    Dmantissap2(destb) = Dmantissap2(valueb)
#define Dbl_set_mantissap1(desta,valuea)		\
    Deposit_dmantissap1(desta,valuea)
#define Dbl_set_mantissap2(destb,valueb)		\
    Dmantissap2(destb) = Dmantissap2(valueb)

#define Dbl_set_exponentmantissa(desta,destb,valuea,valueb)	\
    Deposit_dexponentmantissap1(desta,valuea);			\
    Dmantissap2(destb) = Dmantissap2(valueb)
#define Dbl_set_exponentmantissap1(dest,value)			\
    Deposit_dexponentmantissap1(dest,value)

#define Dbl_copyfromptr(src,desta,destb) \
    Dallp1(desta) = src->wd0;		\
    Dallp2(destb) = src->wd1 
#define Dbl_copytoptr(srca,srcb,dest)	\
    dest->wd0 = Dallp1(srca);		\
    dest->wd1 = Dallp2(srcb)

/*  An infinity is represented with the max exponent and a zero mantissa */
#define Dbl_setinfinity_exponent(dbl_value) \
    Deposit_dexponent(dbl_value,DBL_INFINITY_EXPONENT)
#define Dbl_setinfinity_exponentmantissa(dbl_valueA,dbl_valueB)	\
    Deposit_dexponentmantissap1(dbl_valueA, 			\
    (DBL_INFINITY_EXPONENT << (32-(1+DBL_EXP_LENGTH))));	\
    Dmantissap2(dbl_valueB) = 0
#define Dbl_setinfinitypositive(dbl_valueA,dbl_valueB)		\
    Dallp1(dbl_valueA) 						\
        = (DBL_INFINITY_EXPONENT << (32-(1+DBL_EXP_LENGTH)));	\
    Dmantissap2(dbl_valueB) = 0
#define Dbl_setinfinitynegative(dbl_valueA,dbl_valueB)		\
    Dallp1(dbl_valueA) = ((unsigned int)1<<31) |		\
         (DBL_INFINITY_EXPONENT << (32-(1+DBL_EXP_LENGTH)));	\
    Dmantissap2(dbl_valueB) = 0