[Bug math/18039] New: [ldbl-128] acosl inaccurate

["jsm28 at gcc dot gnu.org" <sourceware-bugzilla at sourceware dot org>]

https://sourceware.org/bugzilla/show_bug.cgi?id=18039

            Bug ID: 18039
           Summary: [ldbl-128] acosl inaccurate
           Product: glibc
           Version: 2.21
            Status: NEW
          Severity: normal
          Priority: P2
         Component: math
          Assignee: unassigned at sourceware dot org
          Reporter: jsm28 at gcc dot gnu.org

The ldbl-128 implementation of acosl uses an inappropriate threshold for when
arguments are small enough to return pi/2, resulting in large errors, e.g.:

Failure: Test: acos (0x1p-60)
Result:
 is:          1.57079632679489661923e+00   0x1.921fb54442d18469898dp+0
 should be:   1.57079632679489661836e+00   0x1.921fb54442d18459898dp+0
 difference:  8.67361737988403547206e-19   0x1.00000000000000000000p-60
 ulp       :  4503599627370496.0000
 max.ulp   :  0.0000

-- 
You are receiving this mail because:
You are on the CC list for the bug.