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: Adrian Bunk <[email protected]>
---
This patch was already sent on:
- 12 Feb 2006
Makefile | 7 -------
init/Kconfig | 37 -------------------------------------
2 files changed, 44 deletions(-)
--- linux-2.6.16-rc2-mm1-full/init/Kconfig.old 2006-02-12 15:30:08.000000000 +0100
+++ linux-2.6.16-rc2-mm1-full/init/Kconfig 2006-02-12 15:30:53.000000000 +0100
@@ -353,45 +353,8 @@
to userspace as tmpfs if TMPFS is enabled. Disabling this
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
help
--- linux-2.6.16-rc2-mm1-full/Makefile.old 2006-02-12 15:30:59.000000000 +0100
+++ linux-2.6.16-rc2-mm1-full/Makefile 2006-02-12 15:31:24.000000000 +0100
@@ -473,15 +473,8 @@
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
CFLAGS += -fomit-frame-pointer
-
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