/* derived from /netlib/fdlibm */ /* @(#)e_fmod.c 1.3 95/01/18 *//* * ==================================================== * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. * * Developed at SunSoft, a Sun Microsystems, Inc. business. * Permission to use, copy, modify, and distribute this * software is freely granted, provided that this notice * is preserved. * ==================================================== */ /* * __ieee754_fmod(x,y) * Return x mod y in exact arithmetic * Method: shift and subtract */ #include "fdlibm.h" static const double one = 1.0, Zero[] = {0.0, -0.0,}; double __ieee754_fmod(double x, double y){ int n,hx,hy,hz,ix,iy,sx,i; unsigned lx,ly,lz; hx = __HI(x); /* high word of x */ lx = __LO(x); /* low word of x */ hy = __HI(y); /* high word of y */ ly = __LO(y); /* low word of y */ sx = hx&0x80000000; /* sign of x */ hx ^=sx; /* |x| */ hy &= 0x7fffffff; /* |y| */ /* purge off exception values */ if((hy|ly)==0||(hx>=0x7ff00000)|| /* y=0,or x not finite */ ((hy|((ly|-ly)>>31))>0x7ff00000)) /* or y is NaN */ return (x*y)/(x*y); if(hx<=hy) { if((hx<hy)||(lx<ly)) return x; /* |x|<|y| return x */ if(lx==ly) return Zero[(unsigned)sx>>31]; /* |x|=|y| return x*0*/ } /* determine ix = ilogb(x) */ if(hx<0x00100000) { /* subnormal x */ if(hx==0) { for (ix = -1043, i=lx; i>0; i<<=1) ix -=1; } else { for (ix = -1022,i=(hx<<11); i>0; i<<=1) ix -=1; } } else ix = (hx>>20)-1023; /* determine iy = ilogb(y) */ if(hy<0x00100000) { /* subnormal y */ if(hy==0) { for (iy = -1043, i=ly; i>0; i<<=1) iy -=1; } else { for (iy = -1022,i=(hy<<11); i>0; i<<=1) iy -=1; } } else iy = (hy>>20)-1023; /* set up {hx,lx}, {hy,ly} and align y to x */ if(ix >= -1022) hx = 0x00100000|(0x000fffff&hx); else { /* subnormal x, shift x to normal */ n = -1022-ix; if(n<=31) { hx = (hx<<n)|(lx>>(32-n)); lx <<= n; } else { hx = lx<<(n-32); lx = 0; } } if(iy >= -1022) hy = 0x00100000|(0x000fffff&hy); else { /* subnormal y, shift y to normal */ n = -1022-iy; if(n<=31) { hy = (hy<<n)|(ly>>(32-n)); ly <<= n; } else { hy = ly<<(n-32); ly = 0; } } /* fix point fmod */ n = ix - iy; while(n--) { hz=hx-hy;lz=lx-ly; if(lx<ly) hz -= 1; if(hz<0){hx = hx+hx+(lx>>31); lx = lx+lx;} else { if((hz|lz)==0) /* return sign(x)*0 */ return Zero[(unsigned)sx>>31]; hx = hz+hz+(lz>>31); lx = lz+lz; } } hz=hx-hy;lz=lx-ly; if(lx<ly) hz -= 1; if(hz>=0) {hx=hz;lx=lz;} /* convert back to floating value and restore the sign */ if((hx|lx)==0) /* return sign(x)*0 */ return Zero[(unsigned)sx>>31]; while(hx<0x00100000) { /* normalize x */ hx = hx+hx+(lx>>31); lx = lx+lx; iy -= 1; } if(iy>= -1022) { /* normalize output */ hx = ((hx-0x00100000)|((iy+1023)<<20)); __HI(x) = hx|sx; __LO(x) = lx; } else { /* subnormal output */ n = -1022 - iy; if(n<=20) { lx = (lx>>n)|((unsigned)hx<<(32-n)); hx >>= n; } else if (n<=31) { lx = (hx<<(32-n))|(lx>>n); hx = sx; } else { lx = hx>>(n-32); hx = sx; } __HI(x) = hx|sx; __LO(x) = lx; x *= one; /* create necessary signal */ } return x; /* exact output */}
/* derived from /netlib/fdlibm */
/* @(#)e_fmod.c 1.3 95/01/18 */
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunSoft, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
/*
* __ieee754_fmod(x,y)
* Return x mod y in exact arithmetic
* Method: shift and subtract
*/
#include "fdlibm.h"
static const double one = 1.0, Zero[] = {0.0, -0.0,};
double __ieee754_fmod(double x, double y)
{
int n,hx,hy,hz,ix,iy,sx,i;
unsigned lx,ly,lz;
hx = __HI(x); /* high word of x */
lx = __LO(x); /* low word of x */
hy = __HI(y); /* high word of y */
ly = __LO(y); /* low word of y */
sx = hx&0x80000000; /* sign of x */
hx ^=sx; /* |x| */
hy &= 0x7fffffff; /* |y| */
/* purge off exception values */
if((hy|ly)==0||(hx>=0x7ff00000)|| /* y=0,or x not finite */
((hy|((ly|-ly)>>31))>0x7ff00000)) /* or y is NaN */
return (x*y)/(x*y);
if(hx<=hy) {
if((hx<hy)||(lx<ly)) return x; /* |x|<|y| return x */
if(lx==ly)
return Zero[(unsigned)sx>>31]; /* |x|=|y| return x*0*/
}
/* determine ix = ilogb(x) */
if(hx<0x00100000) { /* subnormal x */
if(hx==0) {
for (ix = -1043, i=lx; i>0; i<<=1) ix -=1;
} else {
for (ix = -1022,i=(hx<<11); i>0; i<<=1) ix -=1;
}
} else ix = (hx>>20)-1023;
/* determine iy = ilogb(y) */
if(hy<0x00100000) { /* subnormal y */
if(hy==0) {
for (iy = -1043, i=ly; i>0; i<<=1) iy -=1;
} else {
for (iy = -1022,i=(hy<<11); i>0; i<<=1) iy -=1;
}
} else iy = (hy>>20)-1023;
/* set up {hx,lx}, {hy,ly} and align y to x */
if(ix >= -1022)
hx = 0x00100000|(0x000fffff&hx);
else { /* subnormal x, shift x to normal */
n = -1022-ix;
if(n<=31) {
hx = (hx<<n)|(lx>>(32-n));
lx <<= n;
} else {
hx = lx<<(n-32);
lx = 0;
}
}
if(iy >= -1022)
hy = 0x00100000|(0x000fffff&hy);
else { /* subnormal y, shift y to normal */
n = -1022-iy;
if(n<=31) {
hy = (hy<<n)|(ly>>(32-n));
ly <<= n;
} else {
hy = ly<<(n-32);
ly = 0;
}
}
/* fix point fmod */
n = ix - iy;
while(n--) {
hz=hx-hy;lz=lx-ly; if(lx<ly) hz -= 1;
if(hz<0){hx = hx+hx+(lx>>31); lx = lx+lx;}
else {
if((hz|lz)==0) /* return sign(x)*0 */
return Zero[(unsigned)sx>>31];
hx = hz+hz+(lz>>31); lx = lz+lz;
}
}
hz=hx-hy;lz=lx-ly; if(lx<ly) hz -= 1;
if(hz>=0) {hx=hz;lx=lz;}
/* convert back to floating value and restore the sign */
if((hx|lx)==0) /* return sign(x)*0 */
return Zero[(unsigned)sx>>31];
while(hx<0x00100000) { /* normalize x */
hx = hx+hx+(lx>>31); lx = lx+lx;
iy -= 1;
}
if(iy>= -1022) { /* normalize output */
hx = ((hx-0x00100000)|((iy+1023)<<20));
__HI(x) = hx|sx;
__LO(x) = lx;
} else { /* subnormal output */
n = -1022 - iy;
if(n<=20) {
lx = (lx>>n)|((unsigned)hx<<(32-n));
hx >>= n;
} else if (n<=31) {
lx = (hx<<(32-n))|(lx>>n); hx = sx;
} else {
lx = hx>>(n-32); hx = sx;
}
__HI(x) = hx|sx;
__LO(x) = lx;
x *= one; /* create necessary signal */
}
return x; /* exact output */
}