https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65757
Bug ID: 65757
Summary: gfortran gives incorrect result for anint with real*16
argument
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: bugs at dhbailey dot com
gfortran gives an incorrect result for the anint (nearest whole number)
function for certain real*16 arguments. Here is a simple example:
program anintbug
implicit none
real (kind (0.q0)) q1, q2, q3
q1 = 233181505644407.99996948242187500000q0
q2 = anint (q1)
q3 = 233181505644408.00000000000000000000q0
write (6, '(f50.25)') q1, q2, q3
write (6, '(z35)') q1, q2, q3
stop
end
When compiled with "gfortran anintbug.f90", this program produces the following
output. The second result should equal the third result, but does not.
233181505644407.9999694824218750000000000
233181505644407.9999694824218750000000000
233181505644408.0000000000000000000000000
402EA827999FCEEFFFFC000000000000
402EA827999FCEEFFFFC000000000000
402EA827999FCEF00000000000000000
