Unable to generate reloads

[Alexandre Courbot <Alexandre dot Courbot at lifl dot fr>]

Hello everybody,

I'm currently porting GCC to our architecture. I managed to get a basic
MD completed so GCC does compile, but when trying to compile the
following simple program:

char c;

int barfunc()
{
    c = 2;
}

But GCC complains:

test.c: In function `barfunc':
test.c:6: Unable to generate reloads for:

(insn 9 8 10 (set (mem/f:QI (reg/f:SI 15) 0)
        (const_int 2 [0x2])) 1 {movqi} (nil)
    (expr_list:REG_DEAD (reg/f:SI 15)
        (nil)))
test.c:6: Internal compiler error in find_reloads, at reload.c:3486

>From the manual, it looks like there is a problem with the register
allocation or something like this, as it fails in the reload pass - but
I still can't get what's wrong with it. It's the first time I mess with
GCC, and a lot of its internals are still unclear to me. Although the
machine I'm porting GCC to is register-less, I've defined 10 dummy
hard-register for testing purposes. Does someone see something I missed
and could give me a pointer to where the error could come from? Should I
provide more information?

Thank you for your time,
Alex.
-- 
http://www.gnurou.org