[PATCH] 2.5.69 Change to i386 Makefile to distinguish athlons.

[PATCH] 2.5.69 Change to i386 Makefile to distinguish athlons.

[Jonathan Bastien-Filiatrault]

It should succesfully set -march=athlon-<type> according to uname -p.

--- linux-2.5.69/arch/i386/Makefile.orig    2003-05-14 
13:37:19.000000000 -0400
+++ linux-2.5.69/arch/i386/Makefile    2003-05-14 14:50:03.000000000 -0400
@@ -23,7 +23,7 @@
 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)
-
+get_athlon_type = ${shell case `uname -p` in "* 4 *") echo 
"athlon-4";;*XP*) echo "athlon-xp";;*MP*) echo "athlon-mp";;*) echo 
"athlon";;esac}
 # prevent gcc from keeping the stack 16 byte aligned
 CFLAGS += $(call check_gcc,-mpreferred-stack-boundary=2,)

@@ -39,7 +39,7 @@
 cflags-$(CONFIG_MPENTIUMIII)    += $(call 
check_gcc,-march=pentium3,-march=i686)
 cflags-$(CONFIG_MPENTIUM4)    += $(call 
check_gcc,-march=pentium4,-march=i686)
 cflags-$(CONFIG_MK6)        += $(call check_gcc,-march=k6,-march=i586)
-cflags-$(CONFIG_MK7)        += $(call 
check_gcc,-march=athlon,-march=i686 $(align)-functions=4)
+cflags-$(CONFIG_MK7)        += $(call check_gcc,-march=$(call 
get_athlon_type),-march=i686 $(align)-functions=4)
 cflags-$(CONFIG_MK8)        += $(call check_gcc,-march=k8,$(call 
check_gcc,-march=athlon,-march=i686 $(align)-functions=4))
 cflags-$(CONFIG_MCRUSOE)    += -march=i686 $(align)-functions=0 
$(align)-jumps=0 $(align)-loops=0
 cflags-$(CONFIG_MWINCHIPC6)    += $(call 
check_gcc,-march=winchip-c6,-march=i586)

Re: [PATCH] 2.5.69 Change to i386 Makefile to distinguish athlons.

[Dave Jones]

On Wed, May 14, 2003 at 02:57:21PM -0400, Jonathan Bastien-Filiatrault wrote:
 > It should succesfully set -march=athlon-<type> according to uname -p.

"Look, a new way to do something pointless!"

This is just as broken as the previous patch that was posted.
_READ_ the gcc sources. See what those flags do.

The only differences are the enabling of PTA_SSE on the later models.
"Cool, I have SSE, I want optimised SSE routines". Bad luck.
This flag makes damn all difference on integer code. FP code is not
allowed in kernel space, and in the few exceptions where we do use it
(see the memcpy routines), it's guarded by explicit kernel_fpu_begin()
kernel_fpu_end() pairs, something that gcc wouldn't be able to add for us.

		Dave

Re: [PATCH] 2.5.69 Change to i386 Makefile to distinguish athlons.

[Sam Ravnborg]

On Wed, May 14, 2003 at 02:57:21PM -0400, Jonathan Bastien-Filiatrault wrote:
> It should succesfully set -march=athlon-<type> according to uname -p.
> 
> --- linux-2.5.69/arch/i386/Makefile.orig    2003-05-14 
> 13:37:19.000000000 -0400
> +++ linux-2.5.69/arch/i386/Makefile    2003-05-14 14:50:03.000000000 -0400
> @@ -23,7 +23,7 @@
> 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)
> -
> +get_athlon_type = ${shell case `uname -p` in "* 4 *") echo 
> "athlon-4";;*XP*) echo "athlon-xp";;*MP*) echo "athlon-mp";;*) echo 
> "athlon";;esac}

This is broken.
You have no guarantee whatsoever that the kernel is being compiled
for the machine where you do the compilation.

	Sam