Re: [PATCH] Add sh4-nommu-nofpu architecture

[Alexandre Oliva <aoliva at redhat dot com>]

On Mar  8, 2004, Joern Rennecke <renneckej@superh.com> wrote:

> The crucial test is are they in third-party libraries, or in tools
> used to generate ones?

Tools and, possibly, third-party libraries.  We can't tell.

Oh, BTW, we've used number 7 too.

> ! #define EF_SH4_NOMMU_NOFPU 7

This number is a bad idea.  Existing tools will take it as a DSP
machine, because of the macro you removed, and report a very confusing
error message.

Also, your code seems to assume there will always be a machine number
that represents a superset of a given collection of machine numbers,
except for DSP/FPU conflicts, but this is not true.  SH5 is currently
the only oddball, but there may be others.  Ideally, there should be a
way to express `no match' in the table, and have an error be reported,
instead of picking an incorrect match.  We used to return -1 from the
merge macro in such cases before; now there's nothing we can do
AFAICT.

Frankly, I'd much rather have a static inline function with all the
code needed to merge two machine numbers than this table that I don't
find particularly appealing, especially with the additional corner
cases handled in sh_elf_merge_private_data.  Ideally, the merge
function should be used for other purposes, not only in BFD.

-- 
Alexandre Oliva             http://www.ic.unicamp.br/~oliva/
Red Hat Compiler Engineer   aoliva@{redhat.com, gcc.gnu.org}
Free Software Evangelist  oliva@{lsd.ic.unicamp.br, gnu.org}