[Bug middle-end/22141] [4.0/4.1 Regression] Missing optimization when storing structures

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-06-22 13:07 -------
Reduced testcase for the regression:
typedef struct  type
{
  char a;
  char b;
  char c;
  char d;
} type_t;
type_t u;
void
f(void)
{
  u = (type_t){ 1, 2, 3, 4};
}

3.3 produced:
        lis r0,0x102
        lis r2,ha16(_u)
        ori r0,r0,772
        stw r0,lo16(_u)(r2)
        blr

4.0.0 produces:
        lis r11,ha16(_u)
        li r0,2
        la r9,lo16(_u)(r11)
        li r2,1
        stb r0,1(r9)
        li r0,4
        stb r2,lo16(_u)(r11)
        li r2,3
        stb r0,3(r9)
        stb r2,2(r9)
        blr

Which is much slower and larger.

Also this is a code size regression even at -Os.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
          Component|c                           |middle-end
     Ever Confirmed|                            |1
           Keywords|                            |missed-optimization
   Last reconfirmed|0000-00-00 00:00:00         |2005-06-22 13:07:06
               date|                            |
            Summary|Missing optimization when   |[4.0/4.1 Regression] Missing
                   |storing structures          |optimization when storing
                   |                            |structures
   Target Milestone|---                         |4.0.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22141