Steven Bosscher wrote: > Forgive me if I overlooked it, but I can't find in the manuals what > the semantics would be of the following define_expand, from avr.md: > > (define_expand "cbranchsi4" > [(parallel [(set (cc0) > (compare (match_operand:SI 1 "register_operand" "") > (match_operand:SI 2 "nonmemory_operand" ""))) > (clobber (match_scratch:QI 4 ""))]) > (set (pc) > (if_then_else > (match_operator 0 "ordered_comparison_operator" [(cc0) > (const_int 0)]) > (label_ref (match_operand 3 "" "")) > (pc)))] > "") > > The expander performs a SET of CC0 in the first pattern inside the > PARALLEL, and there is a USE of CC0 in the second pattern of the > PARALLEL.
That's incorrect; the second pattern of the PARALLEL is just a CLOBBER. The USE of CC0 happens in a completely separate second INSN that is emitted by this define_expand. (Note that as opposed to define_insn, define_expand can emit more than a single insn.) Bye, Ulrich -- Dr. Ulrich Weigand GNU Toolchain for Linux on System z and Cell BE ulrich.weig...@de.ibm.com
