URL
https://opencores.org/ocsvn/openrisc/openrisc/trunk
Subversion Repositories openrisc
[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [libquadmath/] [math/] [fmodq.c] - Rev 776
Go to most recent revision | Compare with Previous | Blame | View Log
/* e_fmodl.c -- long double version of e_fmod.c. * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz. */ /* * ==================================================== * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. * * Developed at SunPro, a Sun Microsystems, Inc. business. * Permission to use, copy, modify, and distribute this * software is freely granted, provided that this notice * is preserved. * ==================================================== */ /* * fmodq(x,y) * Return x mod y in exact arithmetic * Method: shift and subtract */ #include "quadmath-imp.h" static const __float128 one = 1.0, Zero[] = {0.0, -0.0,}; __float128 fmodq (__float128 x, __float128 y) { int64_t n,hx,hy,hz,ix,iy,sx,i; uint64_t lx,ly,lz; GET_FLT128_WORDS64(hx,lx,x); GET_FLT128_WORDS64(hy,ly,y); sx = hx&0x8000000000000000ULL; /* sign of x */ hx ^=sx; /* |x| */ hy &= 0x7fffffffffffffffLL; /* |y| */ /* purge off exception values */ if((hy|ly)==0||(hx>=0x7fff000000000000LL)|| /* y=0,or x not finite */ ((hy|((ly|-ly)>>63))>0x7fff000000000000LL)) /* 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[(uint64_t)sx>>63]; /* |x|=|y| return x*0*/ } /* determine ix = ilogb(x) */ if(hx<0x0001000000000000LL) { /* subnormal x */ if(hx==0) { for (ix = -16431, i=lx; i>0; i<<=1) ix -=1; } else { for (ix = -16382, i=hx<<15; i>0; i<<=1) ix -=1; } } else ix = (hx>>48)-0x3fff; /* determine iy = ilogb(y) */ if(hy<0x0001000000000000LL) { /* subnormal y */ if(hy==0) { for (iy = -16431, i=ly; i>0; i<<=1) iy -=1; } else { for (iy = -16382, i=hy<<15; i>0; i<<=1) iy -=1; } } else iy = (hy>>48)-0x3fff; /* set up {hx,lx}, {hy,ly} and align y to x */ if(ix >= -16382) hx = 0x0001000000000000LL|(0x0000ffffffffffffLL&hx); else { /* subnormal x, shift x to normal */ n = -16382-ix; if(n<=63) { hx = (hx<<n)|(lx>>(64-n)); lx <<= n; } else { hx = lx<<(n-64); lx = 0; } } if(iy >= -16382) hy = 0x0001000000000000LL|(0x0000ffffffffffffLL&hy); else { /* subnormal y, shift y to normal */ n = -16382-iy; if(n<=63) { hy = (hy<<n)|(ly>>(64-n)); ly <<= n; } else { hy = ly<<(n-64); 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>>63); lx = lx+lx;} else { if((hz|lz)==0) /* return sign(x)*0 */ return Zero[(uint64_t)sx>>63]; hx = hz+hz+(lz>>63); 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[(uint64_t)sx>>63]; while(hx<0x0001000000000000LL) { /* normalize x */ hx = hx+hx+(lx>>63); lx = lx+lx; iy -= 1; } if(iy>= -16382) { /* normalize output */ hx = ((hx-0x0001000000000000LL)|((iy+16383)<<48)); SET_FLT128_WORDS64(x,hx|sx,lx); } else { /* subnormal output */ n = -16382 - iy; if(n<=48) { lx = (lx>>n)|((uint64_t)hx<<(64-n)); hx >>= n; } else if (n<=63) { lx = (hx<<(64-n))|(lx>>n); hx = sx; } else { lx = hx>>(n-64); hx = sx; } SET_FLT128_WORDS64(x,hx|sx,lx); x *= one; /* create necessary signal */ } return x; /* exact output */ }
Go to most recent revision | Compare with Previous | Blame | View Log