Re: GCC fails with -O2 for own Target

[Jens Mehler <jens dot mehler at mni dot thm dot de>]

Am 31.07.13 20:49, schrieb Ian Lance Taylor:
> On Wed, Jul 31, 2013 at 5:35 AM, Jens Mehler <jens.mehler@mni.thm.de> wrote:
> > After testing around I came up with a much easier example to reproduce my
> > error:
> >
> > static unsigned char sbox[256];
> >
> > void
> > test(void)
> > {
> >      int n;
> >      for (n =  0; n < 256; n++)
> >          sbox[n] = (unsigned char) n;
> > }
> >
> > This results in the same error massage:
> > test3.c: In function 'test':
> > test3.c:4:1: internal compiler error: in gen_lowpart_general, at
> > rtlhooks.c:59
> >
> > Via GDB I was able to print the RTX in question:
> > As you can see the code is SYMBOL_REF and therefore the error.
> > I am not really sure how to track that any futher.
> You need to find out what is asking for the low part of a SYMBOL_REF.
>
> Some targets can not load a symbol into a register.  Those target
> break up the SYMBOL_REF in some form, typically into a PLUS of a HIGH
> and a LO_SUM.  For example, the MIPS backend works this way.  You may
> need to do something similar.
>
> Ian
My target can do that don't worry :)
Currently I got it compiled with:
eco32-gcc -O1 -S -fno-tree-loop-optimize test.c

Something else I found out:
As long as the size of the array is small enough the loop gets unrolled 
and it works like a charm.

And I still can't find why there is a low_part requested.

I suspect and error in my machine definition. Currently I am trying to 
track that down.

With best regards,
Jens