FMS 2025.3 built with oneAPI@2025.{2,3}.1 ifx optimizes code to create a divide by zero error

[rickgrubin-noaa]

Description

For spack-stack@2.x / FMS@2025.3 (see configs/common/packages.yaml), ifx will optimize away a check for dividing by zero.

To Reproduce

See the reproducer code in the issue noted above.

Expected behavior

ifx does not optimize away checks for division by zero.

System, compiler, code, ...

• All RDHPCS hosts
• ifx@2025.{2,3}.1

Additional context

This is not a bug with spack / spack-stack per se, noting it here for the sake of completeness.

This is solved by adding the following stanza to configs/common/packages.yaml for package fms

      - any_of:
        - 'fflags="-fp-speculation=safe"'
        when: '%oneapi'
        message: Reduce aggressive speculative optimization for ifx

[climbfuji]

Are you planning to fix this in the release/2.1 branch for 2.1.1? Since the release is only being deployed on NOAA systems, that wouldn't be a problem (bug fix PR --> retag --> reinstall).