Re: target/4855: arm (thumb) backend generates illegal strb instruction]

[Adrian von Bidder <avbidder at acter dot ch>]

Nick Clifton wrote:
> 
> Hi Adrian,
> 
> > The bug is quite robust. It occurs with
> > arm-linux-elf-gcc -mthumb -fpic -mpic-register=r6 -O2
> 
> Well the good news, or bad news, depending upon your point of view, is
> that this bug does not appear to be reproducible with the current CVS
> sources.  At least not for a toolchain configured with
> --target=arm-elf rather than --target=arm-linux-elf.

Yo!

Sorry to inform you that this problem has resurfaced and is reproducible
with both arm-uclinux (my current workdir; don't use the patch I've
posted some time ago) and arm-elf (from todays unmodified cvs) targets.

It is, of course, highly dependent on the workings of the register
allocator, so it depends on optimizer flags.

arm-elf-gcc -mthumb -fpic -mpic-register=r6 -Os shouls show it with
these with the newest cvs.

The code from target/3218 does not seem to have the problem. 'My' code
(target/4855) does still show the problem, however. [1]

greets from Zürich
-- vbi
[1]
typedef enum
{
  REG_NOERROR = 0,
  REG_NOMATCH,
  REG_BADPAT,
  REG_ECOLLATE,
  REG_ECTYPE,
  REG_EESCAPE,
  REG_ESUBREG,
  REG_EBRACK,
  REG_EPAREN,
  REG_EBRACE,
  REG_BADBR,
  REG_ERANGE,
  REG_ESPACE,
  REG_BADRPT,
  REG_EEND,
  REG_ESIZE,
  REG_ERPAREN
}
reg_errcode_t;

typedef unsigned long int reg_syntax_t;

extern int strcoll (const char *__s1, const char *__s2);

reg_errcode_t
compile_range (p_ptr, pend, translate, syntax, b)
     const char **p_ptr, *pend;
     char *translate;
     reg_syntax_t syntax;
     unsigned char *b;
{
  unsigned this_char;

  const char *p = *p_ptr;
  reg_errcode_t ret;
  char range_start[2];
  char range_end[2];
  char ch[2];

  if (p == pend)
    return REG_ERANGE;

  range_start[0] = p[-2];
  range_start[1] = '\0';
  range_end[0] = p[0];
  range_end[1] = '\0';

  (*p_ptr)++;


  ret = syntax & ((((((((((((((((((unsigned long int) 1) << 1) << 1) <<
1) <<
			      1) << 1) << 1) << 1) << 1) << 1) << 1) << 1) <<
		      1) << 1) << 1) << 1) << 1) ? REG_ERANGE : REG_NOERROR;
  ch[1] = '\0';
  for (this_char = 0; this_char <= (unsigned char) -1; ++this_char)
    {
      ch[0] = this_char;
      if (strcoll (range_start, ch) <= 0 && strcoll (ch, range_end) <=
0)
	{
	  (b
	   [((unsigned
	      char) ((translate ? (char)
		      translate[(unsigned char) (this_char)] : (this_char))))
	    / 8] |=
	   1 <<
	   (((unsigned char) (translate ? (char)
			      translate[(unsigned char) (this_char)]
			      : (this_char))) % 8));
	  ret = REG_NOERROR;
	}
    }

  return ret;
}