This is the mail archive of the mailing list for the GCC project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: GCSE store motion

On Wednesday, May 15, 2002, at 01:05 PM, Robert Dewar wrote:

> <No, but it'll help any and all Fortran programs that have to be compiled
> with -fno-automatic because they were developed on systems where local
> variables in subroutines kept their values from call to call.
> Given the number of times my advice on comp.lang.fortran of compiling
> with -fno-automatic actually `stopped the bug', I'd think that's rather
> important ...
> Interesting, considering that *every* version of the Fortran standard has
> emphasized that there is no requirement for local variables in subroutines
> to keep their values from call to call (the only exception is initialized
> data that is never reassigned).

True, but prior to the f77 standard there was no standard way to get the 
functionality.  And just because a standard was adopted in 1978 didn't mean
code written using the new features of that standard was portable; that 
happen until the mid-80s.  Most old compilers SAVEd all locals by default,
and there is a lot of old Fortran around that depends on that behavior.  At
the time, such code was reasonably portable, as much as anything was (f66
was not complete enough or specified fully enough to support true 
To support these programs, every f77 compiler I know of has a switch
equivalent to -fno-automatic, and they always will.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]