Hi! On Mon, Jul 25, 2022 at 01:11:47PM +0800, HAO CHEN GUI wrote: > +(define_insn "<u>madddi4_lowpart" > + [(set (match_operand:DI 0 "gpc_reg_operand" "=r") > + (subreg:DI > + (plus:TI > + (mult:TI (any_extend:TI > + (match_operand:DI 1 "gpc_reg_operand" "r")) > + (any_extend:TI > + (match_operand:DI 2 "gpc_reg_operand" "r"))) > + (any_extend:TI > + (match_operand:DI 3 "gpc_reg_operand" "r"))) > + 8))] > + "TARGET_POWERPC64 && TARGET_MADDLD && BYTES_BIG_ENDIAN" > + "maddld %0,%1,%2,%3" > + [(set_attr "type" "mul")])
So, hrm. This (as well as the _le version) simplifies to just the :DI ops, without subreg. Not properly simplified patterns like this will not ever match, so most optimisations on this will not work :-( Segher
