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[Bug fortran/31114] New: Consistent floating point arithmetic model option


This is a feature request.

It stems from a discussion on gcc-help ("RE: Internal representation of double
variables - 3.4.6 vs 4.1.0").

There is no general, high-level option to enforce any particular arithmetic
model.  Thus running floating point code on different CPUs may give different
results.  While this is a normal feature of floating point arithmetic, there
are well-defined models (such as the IEEE models) that allow for consistent
results without the influence of idiosyncrasies such as the x86 80 bit
registers.

Currently, options that give more consistent behaviour are architecture
specific (such as -mfpmath=sse).  A top-level option to turn on these options
without having to dig into architecture-specific details would be an excellent
addition.  Having an option to switch off a set of optimisations that impact on
the floating point precision would also be a wonderful thing.

In other words, I'm after an analogue of ifort's -mp/-fltconsistency/-mieee-fp.


-- 
           Summary: Consistent floating point arithmetic model option
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: terry at chem dot gu dot se


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31114


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