------- Comment #11 from rearnsha at gcc dot gnu dot org 2009-07-14 14:53
-------
The following define_split works for this specific case, but it needs to be
made more generic (handling IOR and HImode variants).
It also needs reworking for big-endian -- that needs (subreg...3).
(define_split
[(set (match_operand:SI 0 "s_register_operand" "")
(xor:SI (and:SI (ashift:SI (match_operand:SI 1 "s_register_operand" "")
(match_operand:SI 2 "const_int_operand" ""))
(match_operand:SI 3 "const_int_operand" ""))
(zero_extend:SI (subreg:QI (match_dup 1) 0))))]
"TARGET_32BIT && INTVAL (operands[3]) == (255 & (255 << (INTVAL
(operands[2]))))"
[(set (match_dup 0) (xor:SI (ashift:SI (match_dup 1) (match_dup 2))
(match_dup 1)))
(set (match_dup 0) (and:SI (match_dup 0) (const_int 255)))]
"")
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40487
