Re: [PATCH] New style SUBREGs, PLEASE PLEASE testme

[Bill Currie <bcurrie at tssc dot co dot nz>]

David S. Miller wrote:
> It should be indifferent.

Half good news is better than bad news:)

> Let me put it another way, I believe that if a target has defined
> WORDS_BIG_ENDIAN and BYTES_BIG_ENDIAN correctly, the compiler will act
> precisely how it did before.  It should generate the same code sans
> bug fixes.  The only case of the latter I know of are the jump.c
> changes because rtx_renumbered_equal_p() previous to my patch handled
> the 'x' and 'y' parts, if subregs, in an inconsistant manner.

??? (mild confusion)  I think what you're saying is that I will still
have to sort out a reliable (and preferably future proof) way of
convincing gcc that even though DI mode pseudos are big-endian in
memory, they are little-endian in hard-regs (ie, in a pair of registers,
say %r2 and %r3, %r2 is ALWAYS the least significant word, even though
mem addr 0 is the MSW and 4 is the LSW), or is there something hidden
that I can use?  When I ported my hacks from gcc 2.[78].x I used
ALTER_HARD_SUBREG and things seemed to work (though I had other problems
with things like long long constants, bad constraints I think), but I
had to hack reload so it wouldn't strip SUBREGs when the SUBREG number
was 0.

Bill
-- 
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