https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104982
--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Hongtao.liu from comment #4)
> I'm testing
>
> diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
> index 02f298c2846..c74edd1aaef 100644
> --- a/gcc/config/i386/i386.md
> +++ b/gcc/config/i386/i386.md
> @@ -14182,12 +14182,12 @@ (define_insn_and_split "*jcc_bt<mode>_mask"
> (define_split
> [(set (match_operand:SWI248 0 "register_operand")
> (if_then_else:SWI248
> - (ne
> - (zero_extract:SWI48
> - (match_operand:SWI48 1 "register_operand")
> - (const_int 1)
> - (zero_extend:SI (match_operand:QI 2 "register_operand")))
> - (const_int 0))
> + (match_operator 5 "bt_comparison_operator"
> + [(zero_extract:SWI48
> + (match_operand:SWI48 1 "register_operand")
> + (const_int 1)
> + (zero_extend:SI (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
> @@ -14202,6 +14202,8 @@ (define_split
> (match_dup 3)
> (match_dup 4)))]
> {
> + if (GET_CODE (operands[5]) == EQ)
> + std::swap (operands[3], operands[4]);
> operands[2] = lowpart_subreg (SImode, operands[2], QImode);
> })
Ah, yeah - I was hoping for a solution like this.
