[Bug middle-end/113734] [14 regression] libarchive miscompiled (fails libarchive_test_read_format_rar5_extra_field_version test) since r14-8768-g85094e2aa6dba7

["tnfchris at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113734

--- Comment #24 from Tamar Christina <tnfchris at gcc dot gnu.org> ---
The case I thought would go wrong with the above fix is:

#include <string.h>
#include <stdlib.h>
#include <stdio.h>

#define N 306
#define NEEDLE 135

__attribute__ ((noipa, noinline))
int use(int x[N])
{
  printf("res=%d\n", x[NEEDLE]);
  return x[NEEDLE];
}

__attribute__ ((noipa, noinline))
int foo (int i, unsigned short parse_tables_n)
{
  int table[N];
  memset (table, -1, sizeof (table));

  parse_tables_n >>= 9;
  parse_tables_n += 9;
  while (i < N && parse_tables_n--)
    table[i++] = 0;

  return use (table);
}

int main ()
{
  if (foo (0, 0xFFFF) != 0)
    abort ();

  return 0;
}

---
but this seems fine because of the bias_for_lowest which I now understand to be
there to account for this.

So starting a regtest for that patch.