diff options
Diffstat (limited to 'sysdeps/ieee754/dbl-64/e_fmod.c')
| -rw-r--r-- | sysdeps/ieee754/dbl-64/e_fmod.c | 225 |
1 files changed, 135 insertions, 90 deletions
diff --git a/sysdeps/ieee754/dbl-64/e_fmod.c b/sysdeps/ieee754/dbl-64/e_fmod.c index b8548fae4b..c83c2aedb2 100644 --- a/sysdeps/ieee754/dbl-64/e_fmod.c +++ b/sysdeps/ieee754/dbl-64/e_fmod.c @@ -18,111 +18,156 @@ #include <math.h> #include <math_private.h> -static const double one = 1.0, Zero[] = {0.0, -0.0,}; +static const double one = 1.0, Zero[] = { 0.0, -0.0, }; double __ieee754_fmod (double x, double y) { - int32_t n,hx,hy,hz,ix,iy,sx,i; - u_int32_t lx,ly,lz; + int32_t n, hx, hy, hz, ix, iy, sx, i; + u_int32_t lx, ly, lz; - EXTRACT_WORDS(hx,lx,x); - EXTRACT_WORDS(hy,ly,y); - sx = hx&0x80000000; /* sign of x */ - hx ^=sx; /* |x| */ - hy &= 0x7fffffff; /* |y| */ + EXTRACT_WORDS (hx, lx, x); + EXTRACT_WORDS (hy, ly, 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[(u_int32_t)sx>>31]; /* |x|=|y| return x*0*/ - } + /* 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[(u_int32_t) sx >> 31]; /* |x|=|y| return x*0*/ + } - /* determine ix = ilogb(x) */ - if(__builtin_expect(hx<0x00100000, 0)) { /* 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 ix = ilogb(x) */ + if (__builtin_expect (hx < 0x00100000, 0)) /* 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(__builtin_expect(hy<0x00100000, 0)) { /* 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; + /* determine iy = ilogb(y) */ + if (__builtin_expect (hy < 0x00100000, 0)) /* 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(__builtin_expect(ix >= -1022, 1)) - 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; - } + /* set up {hx,lx}, {hy,ly} and align y to x */ + if (__builtin_expect (ix >= -1022, 1)) + 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 (__builtin_expect (iy >= -1022, 1)) + 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; } - if(__builtin_expect(iy >= -1022, 1)) - 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; - } + 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[(u_int32_t)sx>>31]; - hx = hz+hz+(lz>>31); lx = lz+lz; - } + /* 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; } - hz=hx-hy;lz=lx-ly; if(lx<ly) hz -= 1; - if(hz>=0) {hx=hz;lx=lz;} + else + { + if ((hz | lz) == 0) /* return sign(x)*0 */ + return Zero[(u_int32_t) 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[(u_int32_t)sx>>31]; - while(hx<0x00100000) { /* normalize x */ - hx = hx+hx+(lx>>31); lx = lx+lx; - iy -= 1; + /* convert back to floating value and restore the sign */ + if ((hx | lx) == 0) /* return sign(x)*0 */ + return Zero[(u_int32_t) sx >> 31]; + while (hx < 0x00100000) /* normalize x */ + { + hx = hx + hx + (lx >> 31); lx = lx + lx; + iy -= 1; + } + if (__builtin_expect (iy >= -1022, 1)) /* normalize output */ + { + hx = ((hx - 0x00100000) | ((iy + 1023) << 20)); + INSERT_WORDS (x, hx | sx, lx); + } + else /* subnormal output */ + { + n = -1022 - iy; + if (n <= 20) + { + lx = (lx >> n) | ((u_int32_t) hx << (32 - n)); + hx >>= n; + } + else if (n <= 31) + { + lx = (hx << (32 - n)) | (lx >> n); hx = sx; } - if(__builtin_expect(iy>= -1022, 1)) { /* normalize output */ - hx = ((hx-0x00100000)|((iy+1023)<<20)); - INSERT_WORDS(x,hx|sx,lx); - } else { /* subnormal output */ - n = -1022 - iy; - if(n<=20) { - lx = (lx>>n)|((u_int32_t)hx<<(32-n)); - hx >>= n; - } else if (n<=31) { - lx = (hx<<(32-n))|(lx>>n); hx = sx; - } else { - lx = hx>>(n-32); hx = sx; - } - INSERT_WORDS(x,hx|sx,lx); - x *= one; /* create necessary signal */ + else + { + lx = hx >> (n - 32); hx = sx; } - return x; /* exact output */ + INSERT_WORDS (x, hx | sx, lx); + x *= one; /* create necessary signal */ + } + return x; /* exact output */ } strong_alias (__ieee754_fmod, __fmod_finite) |