x86/kbuild: Eliminate duplicate command line options

The options -mno-mmx and -mno-sse are unconditionally added to
KBUILD_CFLAGS in both branches of an ifeq and through a
$(cc-option) further down. We can safely remove the first
instances.

In fact, since the -mno-mmx and -mno-sse options were introduced
simultaneous with the other two options in the $(cc-option)
[according to http://www.gnu.org/software/gcc/gcc-3.1/changes.html],
and since the former were unconditionally used, one can deduce that
only gcc versions knowing about all four are supported. So also
eliminate the $(cc-option) wrap.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Peter Foley <pefoley2@pefoley.com>
Link: http://lkml.kernel.org/r/1410365139-24440-1-git-send-email-linux@rasmusvillemoes.dk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 60087ca37679ccfad7c0417b8e3b32852524ba7c..efea9112bbfefa98fc974a82fb8544d63292691b 100644 (file)
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -50,9 +50,6 @@ ifeq ($(CONFIG_X86_32),y)
 
         KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return
 
-        # Don't autogenerate MMX or SSE instructions
-        KBUILD_CFLAGS += -mno-mmx -mno-sse
-
         # Never want PIC in a 32-bit kernel, prevent breakage with GCC built
         # with nonstandard options
         KBUILD_CFLAGS += -fno-pic
@@ -80,8 +77,7 @@ else
         KBUILD_AFLAGS += -m64
         KBUILD_CFLAGS += -m64
 
-        # Don't autogenerate traditional x87, MMX or SSE instructions
-        KBUILD_CFLAGS += -mno-mmx -mno-sse
+        # Don't autogenerate traditional x87 instructions
         KBUILD_CFLAGS += $(call cc-option,-mno-80387)
         KBUILD_CFLAGS += $(call cc-option,-mno-fp-ret-in-387)
 
@@ -168,7 +164,7 @@ KBUILD_CFLAGS += -Wno-sign-compare
 #
 KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
 # prevent gcc from generating any FP code by mistake
-KBUILD_CFLAGS += $(call cc-option,-mno-sse -mno-mmx -mno-sse2 -mno-3dnow,)
+KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow
 KBUILD_CFLAGS += $(call cc-option,-mno-avx,)
 
 KBUILD_CFLAGS += $(mflags-y)