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x86/kbuild: Eliminate duplicate command line options
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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>
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Rasmus Villemoes authored and Ingo Molnar committed Sep 16, 2014
1 parent 9e82bf0 commit 5c63008
Showing 1 changed file with 2 additions and 6 deletions.
8 changes: 2 additions & 6 deletions arch/x86/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down Expand Up @@ -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)

Expand Down Expand Up @@ -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)
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