[BK/PATCH] better i386 compiler flags

[Jeff Garzik]

[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:

<[e-mail]> (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