Message ID | 59D3C21A.4010704@arm.com |
---|---|
State | New |
Headers | show |
Series | [BZ,#22243] fix log2(0) and log(10) in downward rounding | expand |
On Tue, 3 Oct 2017, Szabolcs Nagy wrote: > On 64bit targets if the SVID compat wrapper is suppressed (e.g. static linking) > then log2(0) and log10(0) returned inf instead of -inf. > > 2017-10-03 Szabolcs Nagy <szabolcs.nagy@arm.com> > > [BZ #22243] > * sysdeps/ieee754/dbl-64/wordsize-64/e_log10.c (__ieee754_log10): Use fabs. > * sysdeps/ieee754/dbl-64/wordsize-64/e_log2.c (__ieee754_log2): Likewise. OK.
diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/e_log10.c b/sysdeps/ieee754/dbl-64/wordsize-64/e_log10.c index 4f5a81669e..cd5567182f 100644 --- a/sysdeps/ieee754/dbl-64/wordsize-64/e_log10.c +++ b/sysdeps/ieee754/dbl-64/wordsize-64/e_log10.c @@ -65,7 +65,7 @@ __ieee754_log10 (double x) if (hx < INT64_C(0x0010000000000000)) { /* x < 2**-1022 */ if (__glibc_unlikely ((hx & UINT64_C(0x7fffffffffffffff)) == 0)) - return -two54 / (x - x); /* log(+-0)=-inf */ + return -two54 / fabs (x); /* log(+-0)=-inf */ if (__glibc_unlikely (hx < 0)) return (x - x) / (x - x); /* log(-#) = NaN */ k -= 54; diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/e_log2.c b/sysdeps/ieee754/dbl-64/wordsize-64/e_log2.c index 5ccb78cf03..f08d5b337d 100644 --- a/sysdeps/ieee754/dbl-64/wordsize-64/e_log2.c +++ b/sysdeps/ieee754/dbl-64/wordsize-64/e_log2.c @@ -81,7 +81,7 @@ __ieee754_log2 (double x) if (hx < INT64_C(0x0010000000000000)) { /* x < 2**-1022 */ if (__glibc_unlikely ((hx & UINT64_C(0x7fffffffffffffff)) == 0)) - return -two54 / (x - x); /* log(+-0)=-inf */ + return -two54 / fabs (x); /* log(+-0)=-inf */ if (__glibc_unlikely (hx < 0)) return (x - x) / (x - x); /* log(-#) = NaN */ k -= 54;