From: Andi Kleen <ak@muc.de>
To: torvalds@osdl.org, akpm@osdl.org, rth@redhat.com,
linux-kernel@vger.kernel.org, jh@suse.cz
Subject: [PATCH] Use -fno-unit-at-a-time if gcc supports it
Date: Fri, 5 Sep 2003 02:47:10 +0200 [thread overview]
Message-ID: <20030905004710.GA31000@averell> (raw)
Hallo,
gcc 3.4 current has switched to default -fno-unit-at-a-time mode for -O2.
The 3.3-Hammer branch compiler used in some distributions also does this.
Unfortunately the kernel doesn't compile with unit-at-a-time currently,
it cannot tolerate the reordering of functions in relation to inline
assembly.
This patch just turns it off when gcc supports the option.
I only did it for i386 for now. The problem is actually not i386 specific
(other architectures break too), so it may make sense to move the check_gcc
stuff into the main Makefile and do it for everybody.
-Andi
--- linux-2.6.0test4-work/arch/i386/Makefile-o 2003-08-23 13:03:08.000000000 +0200
+++ linux-2.6.0test4-work/arch/i386/Makefile 2003-09-05 02:14:07.000000000 +0200
@@ -26,6 +26,10 @@
# prevent gcc from keeping the stack 16 byte aligned
CFLAGS += $(call check_gcc,-mpreferred-stack-boundary=2,)
+# gcc 3.4/3.3-hammer support -funit-at-a-time mode, but the Kernel is not ready
+# for it yet
+CFLAGS += $(call check_gcc,-fno-unit-at-a-time,)
+
align := $(subst -functions=0,,$(call check_gcc,-falign-functions=0,-malign-functions=0))
cflags-$(CONFIG_M386) += -march=i386
next reply other threads:[~2003-09-05 0:47 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-09-05 0:47 Andi Kleen [this message]
2003-09-05 1:05 ` [PATCH] Use -fno-unit-at-a-time if gcc supports it Aaron Lehmann
2003-09-05 1:24 ` Andi Kleen
2003-09-05 5:37 ` Jan Hubicka
2003-09-05 17:27 ` Andi Kleen
2003-09-05 17:59 ` Jeff Garzik
2003-09-06 7:08 ` Jan Hubicka
2003-09-05 14:54 ` Linus Torvalds
2003-09-05 15:17 ` Andreas Jaeger
2003-09-05 16:16 ` Robert Love
2003-09-05 16:10 ` Andreas Jaeger
2003-09-06 7:06 ` Jan Hubicka
2003-09-05 17:19 ` Jakub Jelinek
2003-09-05 17:30 ` Andi Kleen
2003-09-08 9:48 ` Helge Hafting
[not found] <sqnW.3zE.13@gated-at.bofh.it>
[not found] ` <sqHd.3Yj.1@gated-at.bofh.it>
[not found] ` <srtA.53H.1@gated-at.bofh.it>
[not found] ` <sFmW.78P.13@gated-at.bofh.it>
2003-09-06 8:10 ` David Mosberger-Tang
2003-09-08 20:32 ` David Mosberger
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