Bug#332897: set COPTFLAGS in config files to improve performance on subarches
Package: kfreebsd-5
Severity: wishlist
Tags: patch
I'm attaching a patch that should improve performance on high subarches:
- i486 gets -march=i486 and -mtune=i686
- i586 gets -march=i586
- i686 gets -march=i686
Unless this causes runtime errors, I think there's no drawback in adding -march
for the respective subarches.
For -mtune, though, it is not clear what is better. My opinion is that, since
the default kernel is the i486 one, it'll most often be used on i686, so it's
probably better to tune for that cpu (but keeping compatibility with i486).
This isn't only the case for installs on which the user didn't bother to switch
to -586 or -686, but also for Live systems that are forced to use -486.
As for i586, since they installed this package explicitly, it most likely means
we're really on a i586 cpu, so -mtune would do more harm than good.
This patch is a followup to the one in #332836.
-- System Information:
Debian Release: testing/unstable
APT prefers unstable
APT policy: (500, 'unstable')
Architecture: i386 (i686)
Shell: /bin/sh linked to /bin/bash
Kernel: Linux 2.6.11-1-k7
Locale: LANG=en_US, LC_CTYPE=en_US (charmap=ANSI_X3.4-1968) (ignored: LC_ALL set to C)
diff -ur config.old/486 config/486
--- config.old/486 2005-10-09 11:58:29.000000000 +0200
+++ config/486 2005-10-09 12:01:03.000000000 +0200
@@ -5,6 +5,7 @@
cpu I486_CPU
cpu I586_CPU
cpu I686_CPU
+makeoptions COPTFLAGS="-march=i486 -mtune=i686"
ident Debian-i486
# To statically compile in device wiring instead of /boot/device.hints
diff -ur config.old/586 config/586
--- config.old/586 2005-10-09 11:58:29.000000000 +0200
+++ config/586 2005-10-09 12:01:15.000000000 +0200
@@ -4,6 +4,7 @@
machine i386
cpu I586_CPU
cpu I686_CPU
+makeoptions COPTFLAGS="-march=i586"
ident Debian-i586
# To statically compile in device wiring instead of /boot/device.hints
diff -ur config.old/686 config/686
--- config.old/686 2005-10-09 11:56:00.000000000 +0200
+++ config/686 2005-10-09 12:01:29.000000000 +0200
@@ -3,6 +3,7 @@
machine i386
cpu I686_CPU
+makeoptions COPTFLAGS="-march=i686"
ident Debian-i686
# To statically compile in device wiring instead of /boot/device.hints
diff -ur config.old/686-smp config/686-smp
--- config.old/686-smp 2005-10-09 11:56:00.000000000 +0200
+++ config/686-smp 2005-10-09 12:01:42.000000000 +0200
@@ -3,6 +3,7 @@
machine i386
cpu I686_CPU
+makeoptions COPTFLAGS="-march=i686"
ident Debian-i686-SMP
# To statically compile in device wiring instead of /boot/device.hints
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