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Commit d5e54c4e authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 build updates from Ingo Molnar:
 "More Clang support related fixes"

* 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/build: Use cc-option to validate stack alignment parameter
  x86/build: Fix stack alignment for CLang
  x86/build: Drop unused mflags-y
parents 45153920 9e8730b1

arch/x86/Makefile

+8 −9
Original line number Diff line number Diff line
@@ -14,9 +14,11 @@ endif 
# For gcc stack alignment is specified with -mpreferred-stack-boundary,

# clang has the option -mstack-alignment for that purpose.

ifneq ($(call cc-option, -mpreferred-stack-boundary=4),)

        cc_stack_align_opt := -mpreferred-stack-boundary

else ifneq ($(call cc-option, -mstack-alignment=4),)

        cc_stack_align_opt := -mstack-alignment

      cc_stack_align4 := -mpreferred-stack-boundary=2

      cc_stack_align8 := -mpreferred-stack-boundary=3

else ifneq ($(call cc-option, -mstack-alignment=16),)

      cc_stack_align4 := -mstack-alignment=4

      cc_stack_align8 := -mstack-alignment=8

endif



# How to compile the 16-bit code.  Note we always compile for -march=i386;
@@ -36,7 +38,7 @@ REALMODE_CFLAGS := $(M16_CFLAGS) -g -Os -D__KERNEL__ \ 


REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -ffreestanding)

REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -fno-stack-protector)

REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), $(cc_stack_align_opt)=2)

REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), $(cc_stack_align4))

export REALMODE_CFLAGS



# BITS is used as extension for files which are available in a 32 bit
@@ -76,7 +78,7 @@ ifeq ($(CONFIG_X86_32),y) 
        # Align the stack to the register width instead of using the default

        # alignment of 16 bytes. This reduces stack usage and the number of

        # alignment instructions.

        KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align_opt)=2)

        KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align4))



        # Disable unit-at-a-time mode on pre-gcc-4.0 compilers, it makes gcc use

        # a lot more stack due to the lack of sharing of stacklots:
@@ -115,7 +117,7 @@ else 
        # default alignment which keep the stack *mis*aligned.

        # Furthermore an alignment to the register width reduces stack usage

        # and the number of alignment instructions.

        KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align_opt)=3)

        KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align8))



	# Use -mskip-rax-setup if supported.

	KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup)
@@ -232,9 +234,6 @@ KBUILD_CFLAGS += -Wno-sign-compare 
#

KBUILD_CFLAGS += -fno-asynchronous-unwind-tables



KBUILD_CFLAGS += $(mflags-y)

KBUILD_AFLAGS += $(mflags-y)



archscripts: scripts_basic

	$(Q)$(MAKE) $(build)=arch/x86/tools relocs