diff options
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c')
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c | 57 |
1 files changed, 35 insertions, 22 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c b/sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c index 7e58127..c050944 100644 --- a/sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c +++ b/sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c @@ -30,27 +30,28 @@ static char rcsid[] = "$NetBSD: $"; long double __nextafterl(long double x, long double y) { - int64_t hx,hy,ihx,ihy,ilx; - u_int64_t lx; - u_int64_t ly __attribute__ ((unused)); + int64_t hx,hy,ihx,ihy; + uint64_t lx; + double xhi, xlo, yhi; - 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); + yhi = ldbl_high (y); + EXTRACT_WORDS64 (hy, yhi); ihx = hx&0x7fffffffffffffffLL; /* |hx| */ - ilx = lx&0x7fffffffffffffffLL; /* |lx| */ ihy = hy&0x7fffffffffffffffLL; /* |hy| */ - if((((ihx&0x7ff0000000000000LL)==0x7ff0000000000000LL)&& - ((ihx&0x000fffffffffffffLL)!=0)) || /* x is nan */ - (((ihy&0x7ff0000000000000LL)==0x7ff0000000000000LL)&& - ((ihy&0x000fffffffffffffLL)!=0))) /* y is nan */ + if((ihx>0x7ff0000000000000LL) || /* x is nan */ + (ihy>0x7ff0000000000000LL)) /* y is nan */ return x+y; /* signal the nan */ if(x==y) return y; /* x=y, return y */ - if(ihx == 0 && ilx == 0) { /* x == 0 */ - long double u; + if(ihx == 0) { /* x == 0 */ + long double u; /* return +-minsubnormal */ hy = (hy & 0x8000000000000000ULL) | 1; - SET_LDOUBLE_WORDS64(x,hy,0ULL);/* return +-minsubnormal */ + INSERT_WORDS64 (yhi, hy); + x = yhi; u = math_opt_barrier (x); u = u * u; math_force_eval (u); /* raise underflow flag */ @@ -59,10 +60,16 @@ long double __nextafterl(long double x, long double y) long double u; if(x > y) { /* x > y, x -= ulp */ + /* This isn't the largest magnitude correctly rounded + long double as you can see from the lowest mantissa + bit being zero. It is however the largest magnitude + long double with a 106 bit mantissa, and nextafterl + is insane with variable precision. So to make + nextafterl sane we assume 106 bit precision. */ if((hx==0xffefffffffffffffLL)&&(lx==0xfc8ffffffffffffeLL)) return x+x; /* overflow, return -inf */ if (hx >= 0x7ff0000000000000LL) { - SET_LDOUBLE_WORDS64(u,0x7fefffffffffffffLL,0x7c8ffffffffffffeLL); + u = 0x1.fffffffffffff7ffffffffffff8p+1023L; return u; } if(ihx <= 0x0360000000000000LL) { /* x <= LDBL_MIN */ @@ -77,16 +84,19 @@ long double __nextafterl(long double x, long double y) return x; } if (ihx < 0x06a0000000000000LL) { /* ulp will denormal */ - SET_LDOUBLE_WORDS64(u,(hx&0x7ff0000000000000LL),0ULL); + INSERT_WORDS64 (yhi, hx & (0x7ffLL<<52)); + u = yhi; u *= 0x1.0000000000000p-105L; - } else - SET_LDOUBLE_WORDS64(u,(hx&0x7ff0000000000000LL)-0x0690000000000000LL,0ULL); + } else { + INSERT_WORDS64 (yhi, (hx & (0x7ffLL<<52))-(0x069LL<<52)); + u = yhi; + } return x - u; } else { /* x < y, x += ulp */ if((hx==0x7fefffffffffffffLL)&&(lx==0x7c8ffffffffffffeLL)) return x+x; /* overflow, return +inf */ - if ((u_int64_t) hx >= 0xfff0000000000000ULL) { - SET_LDOUBLE_WORDS64(u,0xffefffffffffffffLL,0xfc8ffffffffffffeLL); + if ((uint64_t) hx >= 0xfff0000000000000ULL) { + u = -0x1.fffffffffffff7ffffffffffff8p+1023L; return u; } if(ihx <= 0x0360000000000000LL) { /* x <= LDBL_MIN */ @@ -103,10 +113,13 @@ long double __nextafterl(long double x, long double y) return x; } if (ihx < 0x06a0000000000000LL) { /* ulp will denormal */ - SET_LDOUBLE_WORDS64(u,(hx&0x7ff0000000000000LL),0ULL); + INSERT_WORDS64 (yhi, hx & (0x7ffLL<<52)); + u = yhi; u *= 0x1.0000000000000p-105L; - } else - SET_LDOUBLE_WORDS64(u,(hx&0x7ff0000000000000LL)-0x0690000000000000LL,0ULL); + } else { + INSERT_WORDS64 (yhi, (hx & (0x7ffLL<<52))-(0x069LL<<52)); + u = yhi; + } return x + u; } } |