https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125907
Hongtao Liu <liuhongt at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |liuhongt at gcc dot gnu.org
--- Comment #2 from Hongtao Liu <liuhongt at gcc dot gnu.org> ---
we already have splitter for cmov + bt
;; Help combine recognize bt followed by cmov
(define_split
[(set (match_operand:SWI248 0 "register_operand")
(if_then_else:SWI248
(match_operator 5 "bt_comparison_operator"
[(zero_extract:SWI48
(match_operand:SWI48 1 "nonimmediate_operand")
(const_int 1)
(match_operand:QI 2 "register_operand"))
(const_int 0)])
(match_operand:SWI248 3 "nonimmediate_operand")
(match_operand:SWI248 4 "nonimmediate_operand")))]
"TARGET_USE_BT && TARGET_CMOVE
&& !(MEM_P (operands[3]) && MEM_P (operands[4]))
&& ix86_pre_reload_split ()"
[(set (reg:CCC FLAGS_REG)
(compare:CCC
(const_int 0)
(zero_extract:SWI48 (match_dup 1) (const_int 1) (match_dup 2))))
(set (match_dup 0)
(if_then_else:SWI248 (ltu (reg:CCC FLAGS_REG) (const_int 0))
(match_dup 3)
(match_dup 4)))]
{
if (GET_CODE (operands[5]) == EQ)
std::swap (operands[3], operands[4]);
})
But it only accepts nonimmediate_operand, but here for the testcase in the PR,
it's const_int 0
Failed to match this instruction:
(set (reg:SI 99 [ <retval> ])
(if_then_else:SI (ne (and:SI (reg:SI 103 [ _1 ])
(const_int 1 [0x1]))
(const_int 0 [0]))
(reg:SI 107 [ c ])
(const_int 0 [0])))
