[PATCH] factor common GCC options check

Make the test for supported GCC options into a macro, and add new checks
for -march={winchip-c6,winchip2,c3}.

arch/i386/Makefile

@@ -22,24 +22,26 @@ LDFLAGS_vmlinux := -e stext
 
 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,)
 
 cflags-$(CONFIG_M386)		+= -march=i386
 cflags-$(CONFIG_M486)		+= -march=i486
 cflags-$(CONFIG_M586)		+= -march=i586
 cflags-$(CONFIG_M586TSC)	+= -march=i586
-cflags-$(CONFIG_M586MMX)	+= $(shell if $(CC) -march=pentium-mmx -S -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo "-march=pentium-mmx"; else echo "-march=i586"; fi) 
+cflags-$(CONFIG_M586MMX)	+= $(call check_gcc,-march=pentium-mmx,-march=i586)
 cflags-$(CONFIG_M686)		+= -march=i686
-cflags-$(CONFIG_MPENTIUMIII)	+= $(shell if $(CC) -march=pentium3 -S -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo "-march=pentium3"; else echo "-march=i686"; fi) 
-cflags-$(CONFIG_MPENTIUM4)	+= $(shell if $(CC) -march=pentium4 -S -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo "-march=pentium4"; else echo "-march=i686"; fi) 
-cflags-$(CONFIG_MK6)		+= $(shell if $(CC) -march=k6 -S -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo "-march=k6"; else echo "-march=i586"; fi)
-cflags-$(CONFIG_MK7)		+= $(shell if $(CC) -march=athlon -S -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo "-march=athlon"; else echo "-march=i686 -malign-functions=4"; fi) 
+cflags-$(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)		+= $(call check_gcc,-march=athlon,-march=i686 -malign-functions=4)
 cflags-$(CONFIG_MCRUSOE)	+= -march=i686 -malign-functions=0 -malign-jumps=0 -malign-loops=0
-cflags-$(CONFIG_MWINCHIPC6)	+= -march=i586
-cflags-$(CONFIG_MWINCHIP2)	+= -march=i586
+cflags-$(CONFIG_MWINCHIPC6)	+= $(call check_gcc,-march=winchip-c6,-march=i586)
+cflags-$(CONFIG_MWINCHIP2)	+= $(call check_gcc,-march=winchip2,-march=i586)
 cflags-$(CONFIG_MWINCHIP3D)	+= -march=i586
-cflags-$(CONFIG_MCYRIXIII)	+= -march=i586
+cflags-$(CONFIG_MCYRIXIII)	+= $(call check_gcc,-march=c3,-march=i586)
 
 CFLAGS += $(cflags-y)