PATCH: PR target/59605: Create jump_around_label only if it doesn't exist

[Richard Sandiford]

Hi H.J.,

"H.J. Lu" <hjl.tools@gmail.com> writes:
> diff --git a/gcc/testsuite/gcc.dg/pr59605.c b/gcc/testsuite/gcc.dg/pr59605.c
> new file mode 100644
> index 0000000..4556843
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr59605.c
> @@ -0,0 +1,55 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2" } */
> +/* { dg-additional-options "-minline-stringops-dynamically" { target { i?86-*-* x86_64-*-* } } } */
> +
> +extern void abort (void);
> +
> +#define MAX_OFFSET (sizeof (long long))
> +#define MAX_COPY (1024 + 8192)
> +#define MAX_EXTRA (sizeof (long long))
> +
> +#define MAX_LENGTH (MAX_OFFSET + MAX_COPY + MAX_EXTRA)
> +
> +static union {
> +  char buf[MAX_LENGTH];
> +  long long align_int;
> +  long double align_fp;
> +} u;
> +
> +char A[MAX_LENGTH];
> +
> +int
> +main ()
> +{
> +  int off, len, i;
> +  char *p, *q;
> +
> +  for (i = 0; i < MAX_LENGTH; i++)
> +    A[i] = 'A';
> +
> +  for (off = 0; off < MAX_OFFSET; off++)
> +    for (len = 1; len < MAX_COPY; len++)
> +      {
> +	for (i = 0; i < MAX_LENGTH; i++)
> +	  u.buf[i] = 'a';
> +
> +	p = __builtin_memcpy (u.buf + off, A, len);
> +	if (p != u.buf + off)
> +	  abort ();
> +
> +	q = u.buf;
> +	for (i = 0; i < off; i++, q++)
> +	  if (*q != 'a')
> +	    abort ();
> +
> +	for (i = 0; i < len; i++, q++)
> +	  if (*q != 'A')
> +	    abort ();
> +
> +	for (i = 0; i < MAX_EXTRA; i++, q++)
> +	  if (*q != 'a')
> +	    abort ();
> +      }
> +
> +  return 0;
> +}

The innermost loop bodies are executed over 6x10⁸ times on most targets
and so the test times out for me when using the GDB MIPS simulator.
I'm not sure what the best fix is though.  E.g.:

1. It looks like the PR was for a compile-time failure rather than a run-time
   failure, so one option might be to drop it to dg-do compile.  That'd lose
   a nice executable conformance test though.  I don't like this option.

2. We could drop it to dg-do compile for simulator targets only.  That's still
   lose some conformance testing for simulator targets.

3. We could use a smaller MAX_COPY for simulator targets, which is typically
   how check_effective_target_simulator is used.  I'm not sure whether having
   a smaller MAX_COPY would defeat the original ICE test though.

4. We could split the test into two, a dg-do compile one and a dg-do run one.
   We could then do (3) on the run one.

But there are probably other alternatives too.

I'm willing to do the patch, but has anyone got any suggestions for
what would be best?

Thanks,
Richard