FMS: Set Intel Fortran ifort / ifx compiler flags to not aggressively optimize floating exception code checks

[rickgrubin-noaa]

Per: FMS 2025.03 built with oneAPI@2025.{2,3}.1 ifx optimizes code to create a divide by zero error
#2041

ifx will optimize away a check for dividing by zero.

To Reproduce

See the reproducer code / FMS issue. Also tested against ifort@202{3,4}.x

Expected behavior

ifort / ifx does not optimize away checks for division by zero.

Additional context

Intel Fortran Compiler Developer Guides / References

• ifort@2023.x, @2024.x
• ifx@2025.x

[rickgrubin-noaa]

@spackbot fix style

[spackbot-app]

Let me see if I can fix that for you!

[spackbot-app]

I was able to run spack style --fix for you!

spack style --fix

repos/spack_repo/builtin/packages/fms/package.py
�[1;34m==> �[0mrunning ruff format
�[1;34m==> �[0mrunning ruff check
�[1m�[91minvalid-syntax: �[0m�[1mExpected `]`, found newline�[0m
   �[1m�[94m-->�[0m repos/spack_repo/builtin/packages/fms/package.py:169:76
    �[1m�[94m|�[0m
�[1m�[94m167 |�[0m             self.define("64BIT", "precision=64" in self.spec),
�[1m�[94m168 |�[0m             self.define_from_variant("FPIC", "pic"),
�[1m�[94m169 |�[0m             self.define_from_variant("USE_DEPRECATED_IO", "deprecated_io"),
    �[1m�[94m|�[0m                                                                            �[1m�[91m^�[0m
�[1m�[94m170 |�[0m
�[1m�[94m171 |�[0m             # oneapi ifort / ifx aggressively optimize floating point exception checks
    �[1m�[94m|�[0m

�[1m�[91minvalid-syntax: �[0m�[1mUnexpected indentation�[0m
   �[1m�[94m-->�[0m repos/spack_repo/builtin/packages/fms/package.py:172:1
    �[1m�[94m|�[0m
�[1m�[94m171 |�[0m             # oneapi ifort / ifx aggressively optimize floating point exception checks
�[1m�[94m172 |�[0m             if self.spec.satisfies("%oneapi@2023:"):
    �[1m�[94m|�[0m �[1m�[91m^^^^^^^^^^^^�[0m
�[1m�[94m173 |�[0m                 fflags = "-fp-model=precise -fp-speculation=safe"
�[1m�[94m174 |�[0m                 args.extend(["-DCMAKE_Fortran_FLAGS=%s" % fflags])
    �[1m�[94m|�[0m

�[1m�[91minvalid-syntax: �[0m�[1mExpected a statement�[0m
   �[1m�[94m-->�[0m repos/spack_repo/builtin/packages/fms/package.py:175:9
    �[1m�[94m|�[0m
�[1m�[94m173 |�[0m                 fflags = "-fp-model=precise -fp-speculation=safe"
�[1m�[94m174 |�[0m                 args.extend(["-DCMAKE_Fortran_FLAGS=%s" % fflags])
�[1m�[94m175 |�[0m         ]
    �[1m�[94m|�[0m         �[1m�[91m^�[0m
�[1m�[94m176 |�[0m
�[1m�[94m177 |�[0m         return args
    �[1m�[94m|�[0m

�[1m�[91minvalid-syntax: �[0m�[1mExpected a statement�[0m
   �[1m�[94m-->�[0m repos/spack_repo/builtin/packages/fms/package.py:175:10
    �[1m�[94m|�[0m
�[1m�[94m173 |�[0m                 fflags = "-fp-model=precise -fp-speculation=safe"
�[1m�[94m174 |�[0m                 args.extend(["-DCMAKE_Fortran_FLAGS=%s" % fflags])
�[1m�[94m175 |�[0m         ]
    �[1m�[94m|�[0m          �[1m�[91m^�[0m
�[1m�[94m176 |�[0m
�[1m�[94m177 |�[0m         return args
    �[1m�[94m|�[0m

�[1m�[91minvalid-syntax: �[0m�[1mExpected a statement�[0m
   �[1m�[94m-->�[0m repos/spack_repo/builtin/packages/fms/package.py:178:1
    �[1m�[94m|�[0m
�[1m�[94m177 |�[0m         return args
    �[1m�[94m|�[0m                    �[1m�[91m^�[0m
    �[1m�[94m|�[0m

Found 5 errors.

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