diff options
Diffstat (limited to 'REORG.TODO/sysdeps/ieee754/dbl-64/wordsize-64/e_fmod.c')
| -rw-r--r-- | REORG.TODO/sysdeps/ieee754/dbl-64/wordsize-64/e_fmod.c | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/ieee754/dbl-64/wordsize-64/e_fmod.c b/REORG.TODO/sysdeps/ieee754/dbl-64/wordsize-64/e_fmod.c new file mode 100644 index 0000000000..f686bb6706 --- /dev/null +++ b/REORG.TODO/sysdeps/ieee754/dbl-64/wordsize-64/e_fmod.c @@ -0,0 +1,105 @@ +/* Rewritten for 64-bit machines by Ulrich Drepper <drepper@gmail.com>. */ +/* + * ==================================================== + * 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. + * ==================================================== + */ + +/* + * __ieee754_fmod(x,y) + * Return x mod y in exact arithmetic + * Method: shift and subtract + */ + +#include <math.h> +#include <math_private.h> +#include <stdint.h> + +static const double one = 1.0, Zero[] = {0.0, -0.0,}; + +double +__ieee754_fmod (double x, double y) +{ + int32_t n,ix,iy; + int64_t hx,hy,hz,sx,i; + + EXTRACT_WORDS64(hx,x); + EXTRACT_WORDS64(hy,y); + sx = hx&UINT64_C(0x8000000000000000); /* sign of x */ + hx ^=sx; /* |x| */ + hy &= UINT64_C(0x7fffffffffffffff); /* |y| */ + + /* purge off exception values */ + if(__builtin_expect(hy==0 + || hx >= UINT64_C(0x7ff0000000000000) + || hy > UINT64_C(0x7ff0000000000000), 0)) + /* y=0,or x not finite or y is NaN */ + return (x*y)/(x*y); + if(__builtin_expect(hx<=hy, 0)) { + if(hx<hy) return x; /* |x|<|y| return x */ + return Zero[(uint64_t)sx>>63]; /* |x|=|y| return x*0*/ + } + + /* determine ix = ilogb(x) */ + if(__builtin_expect(hx<UINT64_C(0x0010000000000000), 0)) { + /* subnormal x */ + for (ix = -1022,i=(hx<<11); i>0; i<<=1) ix -=1; + } else ix = (hx>>52)-1023; + + /* determine iy = ilogb(y) */ + if(__builtin_expect(hy<UINT64_C(0x0010000000000000), 0)) { /* subnormal y */ + for (iy = -1022,i=(hy<<11); i>0; i<<=1) iy -=1; + } else iy = (hy>>52)-1023; + + /* set up hx, hy and align y to x */ + if(__builtin_expect(ix >= -1022, 1)) + hx = UINT64_C(0x0010000000000000)|(UINT64_C(0x000fffffffffffff)&hx); + else { /* subnormal x, shift x to normal */ + n = -1022-ix; + hx<<=n; + } + if(__builtin_expect(iy >= -1022, 1)) + hy = UINT64_C(0x0010000000000000)|(UINT64_C(0x000fffffffffffff)&hy); + else { /* subnormal y, shift y to normal */ + n = -1022-iy; + hy<<=n; + } + + /* fix point fmod */ + n = ix - iy; + while(n--) { + hz=hx-hy; + if(hz<0){hx = hx+hx;} + else { + if(hz==0) /* return sign(x)*0 */ + return Zero[(uint64_t)sx>>63]; + hx = hz+hz; + } + } + hz=hx-hy; + if(hz>=0) {hx=hz;} + + /* convert back to floating value and restore the sign */ + if(hx==0) /* return sign(x)*0 */ + return Zero[(uint64_t)sx>>63]; + while(hx<UINT64_C(0x0010000000000000)) { /* normalize x */ + hx = hx+hx; + iy -= 1; + } + if(__builtin_expect(iy>= -1022, 1)) { /* normalize output */ + hx = ((hx-UINT64_C(0x0010000000000000))|((uint64_t)(iy+1023)<<52)); + INSERT_WORDS64(x,hx|sx); + } else { /* subnormal output */ + n = -1022 - iy; + hx>>=n; + INSERT_WORDS64(x,hx|sx); + x *= one; /* create necessary signal */ + } + return x; /* exact output */ +} +strong_alias (__ieee754_fmod, __fmod_finite) |