Re: PATCH: Fix the MIPS ISA ELF setting (Re: RedHat 7.1/mips update)

[Thiemo Seufer <ica2_ts at csv dot ica dot uni-stuttgart dot de>]

Michael Eager wrote:
[snip]
> I think that you should be able to specify exactly one of arch, isa, 
> or cpu.   It makes no sense to me to have both -m4100 and -mcpu=4100.
> The 4100 is a processor, not an architecture.  -mcpu=4100 should be
> a complete specification.  -mips2 is an architecture.  Specifying either 
> one should be a complete specification, with nothing additional necessary.
> Or permitted.  They are not orthogonal specifications.

Specification of an ABI would be needed also. The idea is to
standardize on -march=FOO -mtune=BAR -mabi=BAZ, where -mabi=
could be replaced by -mfp32 and -mgp32 if there is no ABI in
use (e.g. for embedded systems). Specifying an ISA is not as
helpful as it looks: For kernel code the ISA opcodes are not
enough, while the non-ISA opcodes are forbidden in userspace
anyway. Aliasing the -mipsX options to their respective base
CPU type is a simple but working approach.


Thiemo