Hi,
I am trying to implement interleave_high/low and extract_even/odd using vzip and vuzp instructions. I am attaching a patch that attempts to do that. It uses already existing neon_vzip<mode>_internal. The problem with it is that it doesn't express the fact that the two outputs of vzip depend on both inputs, which causes wrong code generation in CSE: for (a,b)<- vzip (c,d) and (e,f) <- vzip (g,d) CSE decides that b==f, since on RTL level b and f depend only on d.
Here is neon_vzip<mode>_internal:
(define_insn "neon_vzip<mode>_internal" [(set (match_operand:VDQW 0 "s_register_operand" "=w") (unspec:VDQW [(match_operand:VDQW 1 "s_register_operand" "0")] UNSPEC_VZIP1)) (set (match_operand:VDQW 2 "s_register_operand" "=w") (unspec:VDQW [(match_operand:VDQW 3 "s_register_operand" "2")] UNSPEC_VZIP2))] "TARGET_NEON" "vzip.<V_sz_elem>\t%<V_reg>0, %<V_reg>2" [(set (attr "neon_type") (if_then_else (ne (symbol_ref "<Is_d_reg>") (const_int 0)) (const_string "neon_bp_simple") (const_string "neon_bp_3cycle")))] )
Is there a way to properly mark the dependence?
Thanks, Ira