[Bug middle-end/24627] [4.1 Regression] xntp miscompiled

[pinskia at gcc dot gnu dot org]

------- Comment #11 from pinskia at gcc dot gnu dot org  2005-11-02 15:53 -------
The following fails with -O1 -fno-tree-sra.
typedef struct {
  struct {unsigned Xl_ui;} Ul_i;
  struct {unsigned Xl_uf;} Ul_f;
} l_fp;
void dolfptoa(short ndec)
{
  l_fp work;
  work.Ul_f.Xl_uf = 0x535f3d8;
  while (ndec > 0) {

    ndec--;
    work.Ul_i.Xl_ui = 0;
    work.Ul_i.Xl_ui = 0;
    if ((work.Ul_f.Xl_uf) & 0x80000000)
      (work.Ul_i.Xl_ui) |= 0x1;
    (work.Ul_f.Xl_uf) <<= 1;

    (work.Ul_i.Xl_ui) <<= 1;
    if ((work.Ul_f.Xl_uf) & 0x80000000)
      (work.Ul_i.Xl_ui) |= 0x1;
    (work.Ul_f.Xl_uf) <<= 1;

    (work.Ul_i.Xl_ui) <<= 1;

    if (!(work.Ul_i.Xl_ui < 10))
      abort ();
  }
}
int main()
{
  dolfptoa(6);
  return 0;
}
----

The -fno-tree-sra is need as otherwise SRA actually does it work and renames
the PHIs correctly.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24627