Bug in ARM compiler

[JoergSilkeSchoen at t-online dot de (Jörg Schön)]

Hello!

I have discovered the following problem with the gcc compiler for the ARM
architecture:

 $ arm-linux-gcc -v

Reading specs from /usr/local/arm-linux/lib/gcc-lib/arm-linux/2.95.2/specs
gcc version 2.95.2 19991024 (release)

 $ arm-linux-gcc -O2 -funroll-loops -c buggy.c

buggy.c: In function `buggy':
buggy.c:29: internal error--unrecognizable insn:
(insn 427 316 312 (set (mem:SI (plus:SI (plus:SI (reg:SI 11 fp)
                    (const_int -4096 [0xfffff000]))
                (const_int -64 [0xffffffc0])) 0)
        (reg:SI 12 ip)) -1 (nil)
    (nil))

 $

I have tried to strip down the buggy routine as much as possible. It seems 
that almost everything that is left is related to the bug.

Regards,
  Joerg Schoen

-- 
      \|/
      @ @
--oOO-(_)-OOo-----------------------------------------------
  Joerg Schoen; Giessener Str. 6; D-35415 Pohlheim; GERMANY
  PHONE +49-6403-978580  EMAIL JoergSilkeSchoen@t-online.de
----ooO-Ooo-------------------------------------------------
typedef struct aa {
  int FID,x[4];
} aa;

typedef struct  {
  aa *fields;
  int *table;
} bb;

void buggy(aa *fieldDefs,int *defaults,int n,int mode)
{
  char fName[4090]; /*  bug disappears if this variable is removed  */
  bb *d;
  int i;

  for(i = 0 ; i < n ; i++) {
    if(fieldDefs[i].FID & 1) mode |= 1;
    d->fields[i] = fieldDefs[i];
    mode |= defaults[i] ? 2 : 1;
  }

  if(mode & 1)
    for(i = 0 ; i < n ; i++) d->table[i] = i;
}