https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105731
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Combine:
Trying 41 -> 44:
41: r120:SI=r119:SI<<0x1a
REG_DEAD r119:SI
44: pc={(r120:SI<0)?L114:pc}
REG_BR_PROB 283038348
Failed to match this instruction:
(parallel [
(set (pc)
(if_then_else (ne (zero_extract:SI (reg:SI 119 [ _7 ])
(const_int 1 [0x1])
(const_int 5 [0x5]))
(const_int 0 [0]))
(label_ref 114)
(pc)))
(set (reg/v:SI 120 [ bits ])
(ashift:SI (reg:SI 119 [ _7 ])
(const_int 26 [0x1a])))
])
Failed to match this instruction:
(parallel [
(set (pc)
(if_then_else (ne (zero_extract:SI (reg:SI 119 [ _7 ])
(const_int 1 [0x1])
(const_int 5 [0x5]))
(const_int 0 [0]))
(label_ref 114)
(pc)))
(set (reg/v:SI 120 [ bits ])
(ashift:SI (reg:SI 119 [ _7 ])
(const_int 26 [0x1a])))
])
Failed to match this instruction:
(parallel [
(set (pc)
(if_then_else (ne (and:SI (lshiftrt:SI (reg:SI 119 [ _7 ])
(const_int 5 [0x5]))
(const_int 1 [0x1]))
(const_int 0 [0]))
(label_ref 114)
(pc)))
(set (reg/v:SI 120 [ bits ])
(ashift:SI (reg:SI 119 [ _7 ])
(const_int 26 [0x1a])))
])
Failed to match this instruction:
(parallel [
(set (pc)
(if_then_else (ne (and:SI (lshiftrt:SI (reg:SI 119 [ _7 ])
(const_int 5 [0x5]))
(const_int 1 [0x1]))
(const_int 0 [0]))
(label_ref 114)
(pc)))
(set (reg/v:SI 120 [ bits ])
(ashift:SI (reg:SI 119 [ _7 ])
(const_int 26 [0x1a])))
])
Successfully matched this instruction:
(set (reg/v:SI 120 [ bits ])
(ashift:SI (reg:SI 119 [ _7 ])
(const_int 26 [0x1a])))
Successfully matched this instruction:
(set (pc)
(if_then_else (ne (zero_extract:SI (reg:SI 119 [ _7 ])
(const_int 1 [0x1])
(const_int 5 [0x5]))
(const_int 0 [0]))
(label_ref 114)
(pc)))
allowing combination of insns 41 and 44
original costs 4 + 14 = 18
replacement costs 4 + 14 = 18
modifying insn i2 41: r120:SI=r119:SI<<0x1a
deferring rescan insn with uid = 41.
modifying insn i3 44:
{pc={(zero_extract(r119:SI,0x1,0x5)!=0)?L114:pc};clobber scratch;}
REG_DEAD r119:SI
REG_BR_PROB 283038348
deferring rescan insn with uid = 44.
The cost for the following instruction is wrong:
(jump_insn 113 110 114 13 (parallel [
(set (pc)
(if_then_else (eq (zero_extract:SI (reg:SI 119 [ _7 ])
(const_int 1 [0x1])
(const_int 5 [0x5]))
(const_int 0 [0]))
(label_ref 59)
(pc)))
(clobber (scratch:SI))
]) "/app/example.cpp":33:26 961 {*tbit_cbranch}
(expr_list:REG_DEAD (reg:SI 119 [ _7 ])
(int_list:REG_BR_PROB 457091900 (nil)))
-> 59)
It should be 18 since it gets splitted into two one which has a cost of 4 and
another which is a cost of 14.
