Subject: re: sparc/sparc64 gcc CFLAGS for optimization
To: David Brownlee <abs@netbsd.org>
From: matthew green <mrg@eterna.com.au>
List: port-sparc
Date: 11/27/2001 13:37:22
I believe sparc64 automatically sets -mcpu=v9. For other boxes
you might want to look at the devel/cpuflags package. It takes
a look at sysctl hw.model and tries to pick a good set of
optimisation flags. If you find any CPU values it doesn't
recognise, please let me know :)
-msupersparc gets you the int multiply and divide which should
be a win :)
it seems to me that the default sparc64 flags should include -multrasparc
to properly enable scheduling for ultrasparc. "sparc" needs to run on
both v7 and v8 hardware (no v6 that i'm aware of??) and the int mul/div
instructions take a Long Time to emulate on the v7 machines, so you don't
want to default to -mv8 or -msupersparc.
sparc64 doesn't set -mcpu=v9. the 64bit compiler defaults to 64bit,
but that's separate (-m32 vs -m64).
.mrg.