Subject: Re: improving ssh performance on sun4m systems
To: Charles Shannon Hendrix <shannon@widomaker.com>
From: David Brownlee <abs@netbsd.org>
List: port-sparc
Date: 03/16/2002 10:18:00
On Sat, 16 Mar 2002, Charles Shannon Hendrix wrote:
> -mv8 enables the instruction set, -mtune=supersparc enables the
> instruction ordering (anything else?), and -msupersparc does both.
>
> I think cpuflags should really issue the latter, because what it
> does say, -mcpu=supersparc, is only the v8 instruction set.
'-mcpu=supersparc' should be synonymous to
'-mcpu=supersparc -mtune=supersparc'. From 'info gcc':
`-mcpu=CPU_TYPE'
Set the instruction set, register set, and instruction scheduling
parameters for machine type CPU_TYPE. Supported values for
CPU_TYPE are `v7', `cypress', `v8', `supersparc', `sparclite',
`f930', `f934', `sparclet', `tsc701', `v9', and `ultrasparc'.
Default instruction scheduling parameters are used for values that
select an architecture and not an implementation. These are `v7',
`v8', `sparclite', `sparclet', `v9'.
Here is a list of each supported architecture and their supported
implementations.
v7: cypress
v8: supersparc
sparclite: f930, f934
sparclet: tsc701
v9: ultrasparc
`-mtune=CPU_TYPE'
Set the instruction scheduling parameters for machine type
CPU_TYPE, but do not set the instruction set or register set that
the option `-mcpu='CPU_TYPE would.
The same values for `-mcpu='CPU_TYPE are used for `-mtune='
CPU_TYPE, though the only useful values are those that select a
particular cpu implementation: `cypress', `supersparc', `f930',
`f934', `tsc701', `ultrasparc'.
I tend to build userland and all packages with cpuflags on
all my boxes. I haven't come up with a clean way to handle
it automatically in kernel builds, so I just tend to go
with adding 'makeoptions COPTS="-O2 -mcpu=supersparc"'
or similar by hand to the config.
--
David/absolute -- www.netbsd.org: No hype required --