diff options
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/s_isinfl.c')
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/s_isinfl.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_isinfl.c b/sysdeps/ieee754/ldbl-128ibm/s_isinfl.c index 5f5b014..6a72822 100644 --- a/sysdeps/ieee754/ldbl-128ibm/s_isinfl.c +++ b/sysdeps/ieee754/ldbl-128ibm/s_isinfl.c @@ -11,6 +11,7 @@ static char rcsid[] = "$NetBSD: $"; /* * isinfl(x) returns 1 if x is inf, -1 if x is -inf, else 0; * no branching! + * slightly dodgy in relying on signed shift right copying sign bit */ #include <math.h> @@ -20,12 +21,16 @@ static char rcsid[] = "$NetBSD: $"; int ___isinfl (long double x) { - int64_t hx,lx; - GET_LDOUBLE_WORDS64(hx,lx,x); - lx = (lx & 0x7fffffffffffffffLL); - lx |= (hx & 0x7fffffffffffffffLL) ^ 0x7ff0000000000000LL; - lx |= -lx; - return ~(lx >> 63) & (hx >> 62); + double xhi; + int64_t hx, mask; + + xhi = ldbl_high (x); + EXTRACT_WORDS64 (hx, xhi); + + mask = (hx & 0x7fffffffffffffffLL) ^ 0x7ff0000000000000LL; + mask |= -mask; + mask >>= 63; + return ~mask & (hx >> 62); } hidden_ver (___isinfl, __isinfl) #ifndef IS_IN_libm |