GCC fails with -O2 for own Target

Question

I have ported the GCC (v4.5.3) to a new target (32-bit RISC processor). So far everything went fine. I wrote my own little C-Lib with basic input output and tested it worked. Until today I never actually tried optimization passes (maybe that was the mistake that lead to this)
Anyway:
During porting and building Newlib I ran into an error that I tracked down to the following code:

unsigned char hexdig[256];

static void htinit ( unsigned char *h , unsigned char *s , int inc)
{
 int i, j;
 for(i = 0; (j = s[i]) !=0; i++)
 h[j] = i + inc;
}

void
hexdig_init ()
{
 htinit(hexdig, (unsigned char *) "**********", 0x10);
 htinit(hexdig, (unsigned char *) "abcdef", 0x10 + 10);
 htinit(hexdig, (unsigned char *) "ABCDEF", 0x10 + 10);
}

Compiling this code without optimization works like a charm, however compiling it with -O2 leads to the following error:
test1.c: In function 'hexdig_init':
test1.c:11:1: internal compiler error: in gen_lowpart_general, at rtlhooks.c:59

Tried with:
eco32-gcc -O2 -S test1.c

My question in short is:
Could this be a targe- backend-error or just some configuration I have missed while building GCC?
Any pointers into the right direction are welcome.

Answer 1

It is most likely an error in your backend. The first step is to break out the debugger and find out why that function is being called with something that is not a MEM. You may want to look at http://gcc.gnu.org/wiki/DebuggingGCC