[Bug middle-end/43987] [4.5/4.6 Regression] type-punning causes broken binaries unless -O0 is used

[rguenth at gcc dot gnu dot org]

------- Comment #16 from rguenth at gcc dot gnu dot org  2010-05-05 14:01 
-------
Runtime testcase:

char B[256 * sizeof(void *)];
typedef void *FILE;
typedef struct globals {
    int c;
    FILE *l;
} __attribute__((may_alias)) T;
void add_input_file(FILE *file)
{
  (*(T*)&B).l[0] = file;
}
extern void abort (void);
int main()
{
  FILE x;
  (*(T*)&B).l = &x;
  add_input_file ((void *)-1);
  if ((*(T*)&B).l[0] != (void *)-1)
    abort ();
  return 0;
}


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43987