Commit 8cab77a2 authored by Adrian Bunk's avatar Adrian Bunk Committed by Sam Ravnborg
Browse files

Kconfig: remove the CONFIG_CC_ALIGN_* options 



I don't see any use case for the CONFIG_CC_ALIGN_* options:
- they are only available if EMBEDDED
- people using EMBEDDED will most likely also enable
  CC_OPTIMIZE_FOR_SIZE
- the default for -Os is to disable alignment

In case someone is doing performance comparisons and discovers that the
default settings gcc chooses aren't good, the only sane thing is to discuss
whether it makes sense to change this, not through offering options to change
this locally.

Signed-off-by: default avatarAdrian Bunk <bunk@stusta.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
parent 7d185983

Makefile

+0 −7
Original line number Diff line number Diff line
@@ -472,13 +472,6 @@ else 
CFLAGS		+= -O2

endif



#Add align options if CONFIG_CC_* is not equal to 0

add-align = $(if $(filter-out 0,$($(1))),$(cc-option-align)$(2)=$($(1)))

CFLAGS		+= $(call add-align,CONFIG_CC_ALIGN_FUNCTIONS,-functions)

CFLAGS		+= $(call add-align,CONFIG_CC_ALIGN_LABELS,-labels)

CFLAGS		+= $(call add-align,CONFIG_CC_ALIGN_LOOPS,-loops)

CFLAGS		+= $(call add-align,CONFIG_CC_ALIGN_JUMPS,-jumps)



ifdef CONFIG_FRAME_POINTER

CFLAGS		+= -fno-omit-frame-pointer $(call cc-option,-fno-optimize-sibling-calls,)

else

init/Kconfig

+0 −37
Original line number Diff line number Diff line
@@ -354,43 +354,6 @@ config SHMEM 
	  option replaces shmem and tmpfs with the much simpler ramfs code,

	  which may be appropriate on small systems without swap.



config CC_ALIGN_FUNCTIONS

	int "Function alignment" if EMBEDDED

	default 0

	help

	  Align the start of functions to the next power-of-two greater than n,

	  skipping up to n bytes.  For instance, 32 aligns functions

	  to the next 32-byte boundary, but 24 would align to the next

	  32-byte boundary only if this can be done by skipping 23 bytes or less.

	  Zero means use compiler's default.



config CC_ALIGN_LABELS

	int "Label alignment" if EMBEDDED

	default 0

	help

	  Align all branch targets to a power-of-two boundary, skipping

	  up to n bytes like ALIGN_FUNCTIONS.  This option can easily

	  make code slower, because it must insert dummy operations for

	  when the branch target is reached in the usual flow of the code.

	  Zero means use compiler's default.



config CC_ALIGN_LOOPS

	int "Loop alignment" if EMBEDDED

	default 0

	help

	  Align loops to a power-of-two boundary, skipping up to n bytes.

	  Zero means use compiler's default.



config CC_ALIGN_JUMPS

	int "Jump alignment" if EMBEDDED

	default 0

	help

	  Align branch targets to a power-of-two boundary, for branch

	  targets where the targets can only be reached by jumping,

	  skipping up to n bytes like ALIGN_FUNCTIONS.  In this case,

	  no dummy operations need be executed.

	  Zero means use compiler's default.



config SLAB

	default y

	bool "Use full SLAB allocator" if EMBEDDED

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