* [BK/PATCH] better i386 compiler flags
@ 2003-01-11 1:26 Jeff Garzik
2003-01-12 0:06 ` Dave Jones
0 siblings, 1 reply; 4+ messages in thread
From: Jeff Garzik @ 2003-01-11 1:26 UTC (permalink / raw)
To: Marcelo Tosatti; +Cc: arjanv, Alan Cox, linux-kernel
[this kills scads of warnings with CONFIG_MCYRIXIII and gcc 3.2,
also starts using -march=pentium3/4/athlon when available. I've been
doing that for a while now without problems.]
Marcelo, please do a
bk pull bk://kernel.bkbits.net/jgarzik/misc-2.4
This will update the following files:
arch/i386/Makefile | 19 +++++++++++--------
1 files changed, 11 insertions(+), 8 deletions(-)
through these ChangeSets:
<jgarzik@redhat.com> (03/01/10 1.994)
arch/i386/Makefile: improved support for gcc 3.2 compiler flags
* Adds useful 'check_gcc' makefile function
* stop using the deprecated -malign* arguments when -falign* is available
* call -march={pentium3,pentium4,k6,athlon,c3,winchip*} when available
--- 1.4/arch/i386/Makefile Mon Sep 30 12:45:01 2002
+++ edited/arch/i386/Makefile Fri Jan 10 19:49:03 2003
@@ -23,8 +23,10 @@
CFLAGS += -pipe
+check_gcc = $(shell if $(CC) $(1) -S -o /dev/null -xc /dev/null > /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi)
+
# prevent gcc from keeping the stack 16 byte aligned
-CFLAGS += $(shell if $(CC) -mpreferred-stack-boundary=2 -S -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo "-mpreferred-stack-boundary=2"; fi)
+CFLAGS += $(call check_gcc,-mpreferred-stack-boundary=2,)
ifdef CONFIG_M386
CFLAGS += -march=i386
@@ -51,19 +53,19 @@
endif
ifdef CONFIG_MPENTIUMIII
-CFLAGS += -march=i686
+CFLAGS += $(call check_gcc,-march=pentium3,-march=i686)
endif
ifdef CONFIG_MPENTIUM4
-CFLAGS += -march=i686
+CFLAGS += $(call check_gcc,-march=pentium4,-march=i686)
endif
ifdef CONFIG_MK6
-CFLAGS += $(shell if $(CC) -march=k6 -S -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo "-march=k6"; else echo "-march=i586"; fi)
+CFLAGS += $(call check_gcc,-march=k6,-march=i586)
endif
ifdef CONFIG_MK7
-CFLAGS += $(shell if $(CC) -march=athlon -S -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo "-march=athlon"; else echo "-march=i686 -malign-functions=4"; fi)
+CFLAGS += $(call check_gcc,-march=athlon,-march=i686 -malign-functions=4)
endif
ifdef CONFIG_MCRUSOE
@@ -71,11 +73,11 @@
endif
ifdef CONFIG_MWINCHIPC6
-CFLAGS += -march=i586
+CFLAGS += $(call check_gcc,-march=winchip-c6,-march=i586)
endif
ifdef CONFIG_MWINCHIP2
-CFLAGS += -march=i586
+CFLAGS += $(call check_gcc,-march=winchip2,-march=i586)
endif
ifdef CONFIG_MWINCHIP3D
@@ -83,7 +85,8 @@
endif
ifdef CONFIG_MCYRIXIII
-CFLAGS += -march=i486 -malign-functions=0 -malign-jumps=0 -malign-loops=0
+CFLAGS += $(call check_gcc,-march=c3,-march=i486)
+CFLAGS += $(call check_gcc,-falign-functions=0 -falign-jumps=0 -falign-loops=0,-malign-functions=0 -malign-jumps=0 -malign-loops=0)
endif
HEAD := arch/i386/kernel/head.o arch/i386/kernel/init_task.o
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [BK/PATCH] better i386 compiler flags
2003-01-11 1:26 [BK/PATCH] better i386 compiler flags Jeff Garzik
@ 2003-01-12 0:06 ` Dave Jones
2003-01-12 7:29 ` Richard Henderson
0 siblings, 1 reply; 4+ messages in thread
From: Dave Jones @ 2003-01-12 0:06 UTC (permalink / raw)
To: Jeff Garzik; +Cc: Marcelo Tosatti, arjanv, Alan Cox, linux-kernel
On Fri, Jan 10, 2003 at 08:26:46PM -0500, Jeff Garzik wrote:
> [this kills scads of warnings with CONFIG_MCYRIXIII and gcc 3.2,
> also starts using -march=pentium3/4/athlon when available. I've been
> doing that for a while now without problems.]
As a heads up, judging from gcc-patches, it seems that the gcc folks are
changing -march over to -mtune at some point soon. I can't fathom the
reasoning behind this other than causing a PITA for users.
Dave
--
| Dave Jones. http://www.codemonkey.org.uk
| SuSE Labs
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [BK/PATCH] better i386 compiler flags
2003-01-12 0:06 ` Dave Jones
@ 2003-01-12 7:29 ` Richard Henderson
2003-01-12 14:52 ` Dave Jones
0 siblings, 1 reply; 4+ messages in thread
From: Richard Henderson @ 2003-01-12 7:29 UTC (permalink / raw)
To: Dave Jones, Jeff Garzik, Marcelo Tosatti, arjanv, Alan Cox,
linux-kernel
On Sun, Jan 12, 2003 at 12:06:02AM +0000, Dave Jones wrote:
> As a heads up, judging from gcc-patches, it seems that the gcc folks are
> changing -march over to -mtune at some point soon. I can't fathom the
> reasoning behind this other than causing a PITA for users.
No, -mcpu -> -mtune. Reason: mcpu means different things
to different targets, and it's confusing.
r~
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [BK/PATCH] better i386 compiler flags
2003-01-12 7:29 ` Richard Henderson
@ 2003-01-12 14:52 ` Dave Jones
0 siblings, 0 replies; 4+ messages in thread
From: Dave Jones @ 2003-01-12 14:52 UTC (permalink / raw)
To: Jeff Garzik, Marcelo Tosatti, arjanv, Alan Cox, linux-kernel
On Sat, Jan 11, 2003 at 11:29:39PM -0800, Richard Henderson wrote:
> On Sun, Jan 12, 2003 at 12:06:02AM +0000, Dave Jones wrote:
> > As a heads up, judging from gcc-patches, it seems that the gcc folks are
> > changing -march over to -mtune at some point soon. I can't fathom the
> > reasoning behind this other than causing a PITA for users.
> No, -mcpu -> -mtune. Reason: mcpu means different things
> to different targets, and it's confusing.
Ah, right. It's still going to make the checkgcc macros in
arch/i386/Makefile get even more 'interesting' though 8-)
Dave
--
| Dave Jones. http://www.codemonkey.org.uk
^ permalink raw reply [flat|nested] 4+ messages in thread
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2003-01-11 1:26 [BK/PATCH] better i386 compiler flags Jeff Garzik
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