The attached file reports 
  foo.c: In function `main':
  foo.c:19: warning: `result1' might be used uninitialized in this function
when compiled with avr-gcc -Os -Wall -c foo.c

gcc was built with
./configure --host=i686-pc-linux-gnu --enable-languages=c --target=avr --disable-nls

The same problem shows up in gcc-ss-3_3-20031110


foo.c:
char a;
 
static inline char rcombine(char r1, char r2)
{
  return r1 ? 0 : r2;
}
 
static inline char Mod1_xx(void)
{
  int i;
 
  for (i = 0; i < 6; i++) a += i;
 
  return 1;
}
 
static inline char Mod1_StdControl_init(void)
{
  char result1;
  char result2;
 
  result1 = rcombine(2, 1);
  result2 = Mod1_xx();
  result1 = rcombine(result1, result2);
  return result1;
}
 
int   main(void)
{
  Mod1_StdControl_init();
  return 0;
}