`nagfor` 7.1 supports half-precision floating-point numbers, but with many bugs

4

A fourth bug, which has been submitted to NAG.

Code (also available at test_compiler/test_mult_nan.f90 at master · zequipe/test_compiler · GitHub):

! test_mult_nan.f90

program test_mult_nan

use, intrinsic :: iso_fortran_env, only : RP => real16
use, intrinsic :: ieee_arithmetic, only : ieee_is_nan

implicit none

real(RP) :: A(2)

A = 1.0_RP
A = -1.0_RP * A

if (any(ieee_is_nan(A)) .or. any(abs(A + 1.0_RP) > 10.0_RP * epsilon(1.0_RP))) then
    write (*, *) 'A = ', A
    write (*, *) 'A is wrong!'
    error stop 1
end if

end program test_mult_nan

Experiment on Ubuntu 22.04:

$ uname -a && nagfor -ieee=full test_mult_nan.f90 && ./a.out
Linux 6.5.0-21-generic #21~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Fri Feb  9 13:32:52 UTC 2 x86_64 x86_64 x86_64 GNU/Linux
NAG Fortran Compiler Release 7.1(Hanzomon) Build 7143
[NAG Fortran Compiler normal termination]
 A is wrong!
 A =  NaN NaN
ERROR STOP: 1

Experiment on macOS (M3 chip):

 % uname -a && nagfor test_mult_nan.f90&& ./a.out
Darwin 23.3.0 Darwin Kernel Version 23.3.0: Wed Dec 20 21:30:59 PST 2023; root:xnu-10002.81.5~7/RELEASE_ARM64_T6030 arm64
NAG Fortran Compiler Release 7.1(Hanzomon) Build 7144
[NAG Fortran Compiler normal termination]
 A =   0.0000  0.0000
 A is wrong!
ERROR STOP: 1