------- Comment #1 from hutchinsonandy at gcc dot gnu dot org 2009-11-29 14:35
-------
Same on 4.5 Head.
The backend patterns match against "MEM AND singlebit".
Combine never considers this.
Incoming RTL and Combine pass dump file extract:
;; Pred edge ENTRY [100.0%] (fallthru)
(note 4 0 2 2 [bb 2] NOTE_INSN_BASIC_BLOCK)
(insn 2 4 3 2 rot.c:25 (set (reg/v:QI 41 [ flag ])
(reg:QI 24 r24 [ flag ])) 4 {*movqi} (expr_list:REG_DEAD (reg:QI 24 r24
[ flag ])
(nil)))
(note 3 2 7 2 NOTE_INSN_FUNCTION_BEG)
(insn 7 3 8 2 rot.c:26 (set (reg:QI 43)
(and:QI (reg/v:QI 41 [ flag ])
(const_int 1 [0x1]))) 43 {andqi3} (expr_list:REG_DEAD (reg/v:QI 41
[ flag ])
(nil)))
(insn 8 7 9 2 rot.c:26 (set (reg:QI 44)
(ashift:QI (reg:QI 43)
(const_int 6 [0x6]))) 59 {*ashlqi3} (expr_list:REG_DEAD (reg:QI 43)
(nil)))
(insn 9 8 10 2 rot.c:26 (set (reg:QI 45)
(mem/s/j:QI (const_int 35 [0x23]) [0 S1 A8])) 4 {*movqi} (nil))
(insn 10 9 11 2 rot.c:26 (set (reg:QI 46)
(and:QI (reg:QI 45)
(const_int -65 [0xffffffbf]))) 43 {andqi3} (expr_list:REG_DEAD
(reg:QI 45)
(nil)))
(insn 11 10 12 2 rot.c:26 (set (reg:QI 47)
(ior:QI (reg:QI 46)
(reg:QI 44))) 46 {iorqi3} (expr_list:REG_DEAD (reg:QI 46)
(expr_list:REG_DEAD (reg:QI 44)
(nil))))
(insn 12 11 0 2 rot.c:26 (set (mem/s/j:QI (const_int 35 [0x23]) [0 S1 A8])
(reg:QI 47)) 4 {*movqi} (expr_list:REG_DEAD (reg:QI 47)
(nil)))
;; End of basic block 2 -> ( 1)
Trying 2 -> 7:
Successfully matched this instruction:
(set (reg:QI 43)
(and:QI (reg:QI 24 r24 [ flag ])
(const_int 1 [0x1])))
deferring deletion of insn with uid = 2.
modifying insn i3 7 r43:QI=r24:QI&0x1
REG_DEAD: r24:QI
deferring rescan insn with uid = 7.
Trying 7 -> 8:
Failed to match this instruction:
(set (reg:QI 44)
(and:QI (ashift:QI (reg:QI 24 r24 [ flag ])
(const_int 6 [0x6]))
(const_int 64 [0x40])))
Trying 9 -> 10:
Failed to match this instruction:
(set (reg:QI 46)
(and:QI (mem/s/j:QI (const_int 35 [0x23]) [0 S1 A8])
(const_int -65 [0xffffffbf])))
Trying 8 -> 11:
Failed to match this instruction:
(set (reg:QI 47)
(ior:QI (ashift:QI (reg:QI 43)
(const_int 6 [0x6]))
(reg:QI 46)))
Trying 10 -> 11:
Failed to match this instruction:
(set (reg:QI 47)
(ior:QI (and:QI (reg:QI 45)
(const_int -65 [0xffffffbf]))
(reg:QI 44)))
Trying 7, 8 -> 11:
Failed to match this instruction:
(set (reg:QI 47)
(ior:QI (and:QI (ashift:QI (reg:QI 24 r24 [ flag ])
(const_int 6 [0x6]))
(const_int 64 [0x40]))
(reg:QI 46)))
Failed to match this instruction:
(set (reg:QI 44)
(and:QI (ashift:QI (reg:QI 24 r24 [ flag ])
(const_int 6 [0x6]))
(const_int 64 [0x40])))
Trying 9, 10 -> 11:
Failed to match this instruction:
(set (reg:QI 47)
(ior:QI (and:QI (mem/s/j:QI (const_int 35 [0x23]) [0 S1 A8])
(const_int -65 [0xffffffbf]))
(reg:QI 44)))
Failed to match this instruction:
(set (reg:QI 46)
(and:QI (mem/s/j:QI (const_int 35 [0x23]) [0 S1 A8])
(const_int -65 [0xffffffbf])))
Trying 10, 8 -> 11:
Failed to match this instruction:
(set (reg:QI 47)
(ior:QI (and:QI (reg:QI 45)
(const_int -65 [0xffffffbf]))
(ashift:QI (reg:QI 43)
(const_int 6 [0x6]))))
Successfully matched this instruction:
(set (reg:QI 46)
(ashift:QI (reg:QI 43)
(const_int 6 [0x6])))
Failed to match this instruction:
(set (reg:QI 47)
(ior:QI (and:QI (reg:QI 45)
(const_int -65 [0xffffffbf]))
(reg:QI 46)))
Trying 11 -> 12:
Failed to match this instruction:
(set (mem/s/j:QI (const_int 35 [0x23]) [0 S1 A8])
(ior:QI (reg:QI 46)
(reg:QI 44)))
Trying 8, 11 -> 12:
Failed to match this instruction:
(set (mem/s/j:QI (const_int 35 [0x23]) [0 S1 A8])
(ior:QI (ashift:QI (reg:QI 43)
(const_int 6 [0x6]))
(reg:QI 46)))
Successfully matched this instruction:
(set (reg:QI 47)
(ashift:QI (reg:QI 43)
(const_int 6 [0x6])))
Failed to match this instruction:
(set (mem/s/j:QI (const_int 35 [0x23]) [0 S1 A8])
(ior:QI (reg:QI 47)
(reg:QI 46)))
Trying 10, 11 -> 12:
Failed to match this instruction:
(set (mem/s/j:QI (const_int 35 [0x23]) [0 S1 A8])
(ior:QI (and:QI (reg:QI 45)
(const_int -65 [0xffffffbf]))
(reg:QI 44)))
Successfully matched this instruction:
(set (reg:QI 47)
(and:QI (reg:QI 45)
(const_int -65 [0xffffffbf])))
Failed to match this instruction:
(set (mem/s/j:QI (const_int 35 [0x23]) [0 S1 A8])
(ior:QI (reg:QI 47)
(reg:QI 44)))
__SREG__ = 0x3f
__SP_H__ = 0x3e
__SP_L__ = 0x3d
__tmp_reg__ = 0
__zero_reg__ = 1
.global __do_copy_data
.global __do_clear_bss
.text
.global set_flag_good
.type set_flag_good, @function
set_flag_good:
/* prologue: function */
/* frame size = 0 */
/* stack size = 0 */
.L__stack_usage = 0
tst r24
brne .L5
cbi 35-0x20,6
ret
.L5:
sbi 35-0x20,6
ret
.size set_flag_good, .-set_flag_good
.global set_flag_bad
.type set_flag_bad, @function
set_flag_bad:
/* prologue: function */
/* frame size = 0 */
/* stack size = 0 */
.L__stack_usage = 0
andi r24,lo8(1)
swap r24
lsl r24
lsl r24
andi r24,lo8(-64)
in r25,35-0x20
andi r25,lo8(-65)
or r25,r24
out 35-0x20,r25
/* epilogue start */
ret
.size set_flag_bad, .-set_flag_bad
--
hutchinsonandy at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |hutchinsonandy at gcc dot
| |gnu dot org
Status|UNCONFIRMED |NEW
Ever Confirmed|0 |1
Last reconfirmed|0000-00-00 00:00:00 |2009-11-29 14:35:09
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42210
