RFC: constraint reshuffle for SH gcc target port

[Richard Earnshaw]

> The gcc.dg/compat/scalar-return-4 c_compat_x_tst.o compile failure
> is yet another of these little bugs that can be easily solved with
> another constraint - but there are more problems like this, the SH
> port is already very low on free constraint letters, and the existing
> constraint letters are also somewhat haphazard.  For instance, the
> 'Z' constraint really belongs into the CONST_OK_FOR_CONSTRAINT space,
> but it didn't fit there because all the letters had been used up.
> Thus, I think it is time to reshuffle some constraints to get some
> more order in the existing constraints and make room for new ones.
> This will affect assembler templates that use any of the renamed
> constraints.  I have attached an outline of the existing usage of
> uppercase constraint letters (lowercase letters that are not defined
> in a machine-independent way are used for register classes on the SH),
> what constraints I want to change, and list of the uppercase constraints
> after the reshuffle.
> 

Doesn't this break any constraints in asm statements that use the 
constraint letters you are changing?

R.