This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: PATCH: Add pa8000 scheduling
- To: Jerry Quinn <jquinn at nortelnetworks dot com>, egcs-patches at egcs dot cygnus dot com
- Subject: Re: PATCH: Add pa8000 scheduling
- From: Richard Henderson <rth at cygnus dot com>
- Date: Fri, 5 Mar 1999 17:03:46 -0800
- References: <199903051622.IAA24682@cygnus.com>
On Fri, Mar 05, 1999 at 04:22:15PM +0000, Jerry Quinn wrote:
> + ;; Shifts and memory ops actually execute in one of the integer
> + ;; ALUs, but we can't really model that.
Sure we can. Look at alpha ev6_ebox and ev6_[ul].
Alpha ev6 has 4 `ebox' pipes, divided into upper and lower (u, l)
and left and right (0, 1). Basic alu stuff can issue anywhere,
but loads, stores, mult, shift, branches, and motion video insns
issue to some subset of those pipes.
So what you do is pretend you've got more units than actually
exist, but that insns need several in order to issue.
So we say there are 4 ebox units and 2 upper units. Shifts
then, require one of each in order to issue.
r~