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Subject: [Bug other/56314] New: Please allow per-function specification of register conventions
Date: Thu, 14 Feb 2013 01:56:00 -0000
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56314

             Bug #: 56314
           Summary: Please allow per-function specification of register
                    conventions
    Classification: Unclassified
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: other
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: hpa@zytor.com


gcc allows register specifications (saved, clobbered, reserved) to be changed
on a per-file basis.  However, for optimization uses it would be much more
useful if they could be defined on a per-function basis using attributes, just
as calling conventions can be specified with attributes.

In the Linux kernel world we currently have several uses of functions with ad
hoc calling conventions.  We have to wrap them in assembly wrappers, and either
write them in assembly or put them in separate files with the calling
convention specified with compiler options.