This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
How to use "nothing" in pipeline description?
- From: "H. J. Lu" <hjl at lucon dot org>
- To: gcc at gcc dot gnu dot org
- Date: Fri, 25 Aug 2006 10:42:57 -0700
- Subject: How to use "nothing" in pipeline description?
If an instruction has latency 3 and throughput 1, should I write it as
(define_insn_reservation "simple" 3
(eq_attr "memory" "none")
"p0")
or
(define_insn_reservation "simple" 3
(eq_attr "memory" "none")
"p0,nothing*2")
Are they equivalent? What happens when there are fewer reservation
cycles than default latency?
Thanks.
H.J.