diff options
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/e_fmodl.c')
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/e_fmodl.c | 125 |
1 files changed, 66 insertions, 59 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/e_fmodl.c b/sysdeps/ieee754/ldbl-128ibm/e_fmodl.c index a60963c84d..a140fb322d 100644 --- a/sysdeps/ieee754/ldbl-128ibm/e_fmodl.c +++ b/sysdeps/ieee754/ldbl-128ibm/e_fmodl.c @@ -27,76 +27,83 @@ static const long double one = 1.0, Zero[] = {0.0, -0.0,}; long double __ieee754_fmodl (long double x, long double y) { - int64_t n,hx,hy,hz,ix,iy,sx, i; - u_int64_t lx,ly,lz; - int temp; + int64_t hx, hy, hz, sx, sy; + uint64_t lx, ly, lz; + int n, ix, iy; + double xhi, xlo, yhi, ylo; - GET_LDOUBLE_WORDS64(hx,lx,x); - GET_LDOUBLE_WORDS64(hy,ly,y); + ldbl_unpack (x, &xhi, &xlo); + EXTRACT_WORDS64 (hx, xhi); + EXTRACT_WORDS64 (lx, xlo); + ldbl_unpack (y, &yhi, &ylo); + EXTRACT_WORDS64 (hy, yhi); + EXTRACT_WORDS64 (ly, ylo); sx = hx&0x8000000000000000ULL; /* sign of x */ - hx ^=sx; /* |x| */ - hy &= 0x7fffffffffffffffLL; /* |y| */ + hx ^= sx; /* |x| */ + sy = hy&0x8000000000000000ULL; /* sign of y */ + hy ^= sy; /* |y| */ /* purge off exception values */ - if(__builtin_expect((hy|(ly&0x7fffffffffffffff))==0 || + if(__builtin_expect(hy==0 || (hx>=0x7ff0000000000000LL)|| /* y=0,or x not finite */ (hy>0x7ff0000000000000LL),0)) /* or y is NaN */ return (x*y)/(x*y); - if(__builtin_expect(hx<=hy,0)) { - if((hx<hy)||(lx<ly)) return x; /* |x|<|y| return x */ - if(lx==ly) - return Zero[(u_int64_t)sx>>63]; /* |x|=|y| return x*0*/ + if (__builtin_expect (hx <= hy, 0)) + { + /* If |x| < |y| return x. */ + if (hx < hy) + return x; + /* At this point the absolute value of the high doubles of + x and y must be equal. */ + /* If the low double of y is the same sign as the high + double of y (ie. the low double increases |y|)... */ + if (((ly ^ sy) & 0x8000000000000000LL) == 0 + /* ... then a different sign low double to high double + for x or same sign but lower magnitude... */ + && (int64_t) (lx ^ sx) < (int64_t) (ly ^ sy)) + /* ... means |x| < |y|. */ + return x; + /* If the low double of x differs in sign to the high + double of x (ie. the low double decreases |x|)... */ + if (((lx ^ sx) & 0x8000000000000000LL) != 0 + /* ... then a different sign low double to high double + for y with lower magnitude (we've already caught + the same sign for y case above)... */ + && (int64_t) (lx ^ sx) > (int64_t) (ly ^ sy)) + /* ... means |x| < |y|. */ + return x; + /* If |x| == |y| return x*0. */ + if ((lx ^ sx) == (ly ^ sy)) + return Zero[(uint64_t) sx >> 63]; } - /* determine ix = ilogb(x) */ - if(__builtin_expect(hx<0x0010000000000000LL,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>>52)-0x3ff; - - /* determine iy = ilogb(y) */ - if(__builtin_expect(hy<0x0010000000000000LL,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>>52)-0x3ff; - /* Make the IBM extended format 105 bit mantissa look like the ieee854 112 bit mantissa so the following operations will give the correct result. */ - ldbl_extract_mantissa(&hx, &lx, &temp, x); - ldbl_extract_mantissa(&hy, &ly, &temp, y); + ldbl_extract_mantissa(&hx, &lx, &ix, x); + ldbl_extract_mantissa(&hy, &ly, &iy, y); - /* set up {hx,lx}, {hy,ly} and align y to x */ - if(__builtin_expect(ix >= -1022, 1)) - hx = 0x0001000000000000LL|(0x0000ffffffffffffLL&hx); - else { /* subnormal x, shift x to normal */ - n = -1022-ix; - if(n<=63) { - hx = (hx<<n)|(lx>>(64-n)); - lx <<= n; - } else { - hx = lx<<(n-64); - lx = 0; - } - } - if(__builtin_expect(iy >= -1022, 1)) - hy = 0x0001000000000000LL|(0x0000ffffffffffffLL&hy); - else { /* subnormal y, shift y to normal */ - n = -1022-iy; - if(n<=63) { - hy = (hy<<n)|(ly>>(64-n)); - ly <<= n; - } else { - hy = ly<<(n-64); - ly = 0; - } - } + if (__builtin_expect (ix == -IEEE754_DOUBLE_BIAS, 0)) + { + /* subnormal x, shift x to normal. */ + while ((hx & (1LL << 48)) == 0) + { + hx = (hx << 1) | (lx >> 63); + lx = lx << 1; + ix -= 1; + } + } + + if (__builtin_expect (iy == -IEEE754_DOUBLE_BIAS, 0)) + { + /* subnormal y, shift y to normal. */ + while ((hy & (1LL << 48)) == 0) + { + hy = (hy << 1) | (ly >> 63); + ly = ly << 1; + iy -= 1; + } + } /* fix point fmod */ n = ix - iy; @@ -104,7 +111,7 @@ __ieee754_fmodl (long double x, long double y) 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&0x7fffffffffffffff))==0) /* return sign(x)*0 */ + if((hz|lz)==0) /* return sign(x)*0 */ return Zero[(u_int64_t)sx>>63]; hx = hz+hz+(lz>>63); lx = lz+lz; } @@ -113,7 +120,7 @@ __ieee754_fmodl (long double x, long double y) if(hz>=0) {hx=hz;lx=lz;} /* convert back to floating value and restore the sign */ - if((hx|(lx&0x7fffffffffffffff))==0) /* return sign(x)*0 */ + if((hx|lx)==0) /* return sign(x)*0 */ return Zero[(u_int64_t)sx>>63]; while(hx<0x0001000000000000LL) { /* normalize x */ hx = hx+hx+(lx>>63); lx = lx+lx; |