diff options
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/s_logbl.c')
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/s_logbl.c | 35 |
1 files changed, 21 insertions, 14 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_logbl.c b/sysdeps/ieee754/ldbl-128ibm/s_logbl.c index f38b129971..678b6cad57 100644 --- a/sysdeps/ieee754/ldbl-128ibm/s_logbl.c +++ b/sysdeps/ieee754/ldbl-128ibm/s_logbl.c @@ -13,10 +13,6 @@ * ==================================================== */ -#if defined(LIBM_SCCS) && !defined(lint) -static char rcsid[] = "$NetBSD: $"; -#endif - /* * long double logbl(x) * IEEE 754 logb. Included to pass IEEE test suite. Not recommend. @@ -27,16 +23,27 @@ static char rcsid[] = "$NetBSD: $"; #include <math_private.h> #include <math_ldbl_opt.h> -long double __logbl(long double x) +long double +__logbl (long double x) { - int64_t lx,hx; - GET_LDOUBLE_WORDS64(hx,lx,x); - hx &= 0x7fffffffffffffffLL; /* high |x| */ - if((hx|(lx&0x7fffffffffffffffLL))==0) return -1.0/fabs(x); - if(hx>=0x7ff0000000000000LL) return x*x; - if((hx>>=52)==0) /* IEEE 754 logb */ - return -1022.0; - else - return (long double) (hx-0x3ff); + int64_t lx, hx, rhx; + + GET_LDOUBLE_WORDS64 (hx, lx, x); + hx &= 0x7fffffffffffffffLL; /* high |x| */ + if ((hx | (lx & 0x7fffffffffffffffLL)) == 0) + return -1.0 / fabs (x); + if (hx >= 0x7ff0000000000000LL) + return x * x; + if (__builtin_expect ((rhx = hx >> 52) == 0, 0)) + { + /* POSIX specifies that denormal number is treated as + though it were normalized. */ + int m1 = (hx == 0) ? 0 : __builtin_clzll (hx); + int m2 = (lx == 0) ? 0 : __builtin_clzll (lx); + int ma = (m1 == 0) ? m2 + 64 : m1; + return -1022.0 + (long double)(11 - ma); + } + return (long double) (rhx - 1023); } + long_double_symbol (libm, __logbl, logbl); |