[Bug middle-end/22141] [4.0/4.1/4.2/4.3 Regression] Missing optimization when storing structures

["rguenth at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #11 from rguenth at gcc dot gnu dot org  2008-01-18 12:08 -------
For 3.3-hammer I get (x86_64):

;; Function f

(note 2 0 3 NOTE_INSN_DELETED)

(note 3 2 4 NOTE_INSN_FUNCTION_BEG) 

(note 4 3 5 NOTE_INSN_DELETED)

(note 5 4 6 NOTE_INSN_DELETED)

(note 6 5 8 NOTE_INSN_DELETED)

(insn 8 6 9 (nil) (set (reg/v:SI 58 [ <anonymous> ])
        (const_int 0 [0x0])) -1 (nil)
    (nil))

(insn 9 8 10 (nil) (set (strict_low_part (subreg:QI (reg/v:SI 58 [ <anonymous>
]) 0))
        (const_int 1 [0x1])) -1 (nil)
    (nil))

(insn 10 9 11 (nil) (set (reg:DI 59)
        (const_int 2 [0x2])) -1 (nil)
    (expr_list:REG_EQUAL (const_int 2 [0x2])
        (nil)))

(insn 11 10 13 (nil) (set (zero_extract:DI (subreg:DI (reg/v:SI 58 [
<anonymous> ]) 0)
            (const_int 8 [0x8])
            (const_int 8 [0x8]))
        (reg:DI 59)) -1 (nil)
    (nil))

(insn 13 11 14 (nil) (parallel [
            (set (reg/v:SI 58 [ <anonymous> ])
                (and:SI (reg/v:SI 58 [ <anonymous> ])
                    (const_int -16711681 [0xffffffffff00ffff])))
            (clobber (reg:CC 17 flags))
        ]) -1 (nil)
    (nil))

(insn 14 13 16 (nil) (parallel [
            (set (reg/v:SI 58 [ <anonymous> ])
                (ior:SI (reg/v:SI 58 [ <anonymous> ])
                    (const_int 196608 [0x30000])))
            (clobber (reg:CC 17 flags))
        ]) -1 (nil)
    (nil))

(insn 16 14 17 (nil) (parallel [
            (set (reg/v:SI 58 [ <anonymous> ])
                (and:SI (reg/v:SI 58 [ <anonymous> ])
                    (const_int 16777215 [0xffffff])))
            (clobber (reg:CC 17 flags))
        ]) -1 (nil)
    (nil))

(insn 17 16 18 (nil) (parallel [
            (set (reg/v:SI 58 [ <anonymous> ])
                (ior:SI (reg/v:SI 58 [ <anonymous> ])
                    (const_int 67108864 [0x4000000])))
            (clobber (reg:CC 17 flags))
        ]) -1 (nil)
    (nil))

(insn 18 17 19 (nil) (set (mem/s:SI (symbol_ref:DI ("u")) [2 u+0 S4 A8])
        (reg/v:SI 58 [ <anonymous> ])) -1 (nil)
    (nil))

(note 19 18 21 NOTE_INSN_FUNCTION_END)

(code_label 21 19 0 1 "" [0 uses])


while on the trunk I see:


;; Function f (f)


;;
;; Full RTL generated for this function:
;;
(note 1 0 3 NOTE_INSN_DELETED)

;; Start of basic block ( 0) -> 2
;; Pred edge  ENTRY [100.0%]  (fallthru)
(note 3 1 2 2 [bb 2] NOTE_INSN_BASIC_BLOCK)

(note 2 3 4 2 NOTE_INSN_FUNCTION_BEG)
;; End of basic block 2 -> ( 3) 

;; Succ edge  3 [100.0%]  (fallthru)

;; Start of basic block ( 2) -> 3
;; Pred edge  2 [100.0%]  (fallthru)
(note 4 2 5 3 [bb 3] NOTE_INSN_BASIC_BLOCK)

(insn 5 4 6 3 t.c:12 (set (reg/f:DI 58)
        (symbol_ref:DI ("u") <var_decl 0x2b813a2b8460 u>)) -1 (nil))

(insn 6 5 7 3 t.c:12 (set (mem/s/c:QI (reg/f:DI 58) [0 u.a+0 S1 A8])
        (const_int 1 [0x1])) -1 (nil))

(insn 7 6 8 3 t.c:12 (set (reg/f:DI 59)
        (const:DI (plus:DI (symbol_ref:DI ("u") <var_decl 0x2b813a2b8460 u>)
                (const_int 1 [0x1])))) -1 (nil))

(insn 8 7 9 3 t.c:12 (set (mem/s/c:QI (reg/f:DI 59) [0 u.b+0 S1 A8])
        (const_int 2 [0x2])) -1 (nil))

(insn 9 8 10 3 t.c:12 (set (reg/f:DI 60)
        (const:DI (plus:DI (symbol_ref:DI ("u") <var_decl 0x2b813a2b8460 u>)
                (const_int 2 [0x2])))) -1 (nil))

(insn 10 9 11 3 t.c:12 (set (mem/s/c:QI (reg/f:DI 60) [0 u.c+0 S1 A8])
        (const_int 3 [0x3])) -1 (nil))

(insn 11 10 12 3 t.c:12 (set (reg/f:DI 61)
        (const:DI (plus:DI (symbol_ref:DI ("u") <var_decl 0x2b813a2b8460 u>)
                (const_int 3 [0x3])))) -1 (nil))

(insn 12 11 17 3 t.c:12 (set (mem/s/c:QI (reg/f:DI 61) [0 u.d+0 S1 A8])
        (const_int 4 [0x4])) -1 (nil))
;; End of basic block 3 -> ( 4)

;; Succ edge  4 [100.0%]  (fallthru)

;; Start of basic block ( 3) -> 4
;; Pred edge  3 [100.0%]  (fallthru)
(note 17 12 14 4 [bb 4] NOTE_INSN_BASIC_BLOCK)

(jump_insn 14 17 15 4 t.c:13 (set (pc)
        (label_ref 16)) -1 (nil))
;; End of basic block 4 -> ( 6)

;; Succ edge  6 [100.0%] 

(barrier 15 14 13)

;; Start of basic block () -> 5
(code_label 13 15 18 5 1 "" [0 uses])

(note 18 13 16 5 [bb 5] NOTE_INSN_BASIC_BLOCK)
;; End of basic block 5 -> ( 6) 

;; Succ edge  6 [100.0%]  (fallthru)

;; Start of basic block ( 4 5) -> 6
;; Pred edge  4 [100.0%]
;; Pred edge  5 [100.0%]  (fallthru)
(code_label 16 18 19 6 2 "" [1 uses])

(note 19 16 0 6 [bb 6] NOTE_INSN_BASIC_BLOCK)
;; End of basic block 6 -> ( 1)

;; Succ edge  EXIT [100.0%]  (fallthru)


-- 


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