kbuild: deprecate cc-option-align

Commit Message

Masahiro Yamada June 19, 2017, 7:28 a.m. UTC

Documentation/kbuild/makefiles.txt says the change for align options
occurred at GCC 3.0, and Documentation/process/changes.rst says the
minimal supported GCC version is 3.2, so it should be safe to hard-code
-falign* options.

Fix the only user arch/x86/Makefile_32.cpu and deprecate the
cc-option-align.

Signed-off-by: Masahiro Yamada <[e-mail]>
---

x86 maintainers,

If this patch looks OK, could you give me Acked-by?


 Documentation/kbuild/makefiles.txt | 16 ----------------
 arch/x86/Makefile_32.cpu           |  7 +++----
 scripts/Kbuild.include             |  5 -----
 3 files changed, 3 insertions(+), 25 deletions(-)

Comments

Ingo Molnar June 22, 2017, 8:59 a.m. UTC | #1

* Masahiro Yamada <[e-mail]> wrote:

> Documentation/kbuild/makefiles.txt says the change for align options
> occurred at GCC 3.0, and Documentation/process/changes.rst says the
> minimal supported GCC version is 3.2, so it should be safe to hard-code
> -falign* options.
> 
> Fix the only user arch/x86/Makefile_32.cpu and deprecate the
> cc-option-align.
> 
> Signed-off-by: Masahiro Yamada <[e-mail]>
> ---
> 
> x86 maintainers,
> 
> If this patch looks OK, could you give me Acked-by?

LGTM in principle, although I haven't tested it:

   Acked-by: Ingo Molnar <[e-mail]>

Thanks,

	Ingo
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Masahiro Yamada June 25, 2017, 4 a.m. UTC | #2

2017-06-19 16:28 GMT+09:00 Masahiro Yamada <[e-mail]>:
> Documentation/kbuild/makefiles.txt says the change for align options
> occurred at GCC 3.0, and Documentation/process/changes.rst says the
> minimal supported GCC version is 3.2, so it should be safe to hard-code
> -falign* options.
>
> Fix the only user arch/x86/Makefile_32.cpu and deprecate the
> cc-option-align.
>
> Signed-off-by: Masahiro Yamada <[e-mail]>

Applied to linux-kbuild/kbuild.

Patch

diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
index 1c49e87cea4f..247fb331c4b2 100644
--- a/Documentation/kbuild/makefiles.txt
+++ b/Documentation/kbuild/makefiles.txt
@@ -486,22 +486,6 @@  more details, with real examples.
 	respectively.
 	Note: cc-option-yn uses KBUILD_CFLAGS for $(CC) options
 
-    cc-option-align
-	gcc versions >= 3.0 changed the type of options used to specify
-	alignment of functions, loops etc. $(cc-option-align), when used
-	as prefix to the align options, will select the right prefix:
-	gcc < 3.00
-		cc-option-align = -malign
-	gcc >= 3.00
-		cc-option-align = -falign
-
-	Example:
-		KBUILD_CFLAGS += $(cc-option-align)-functions=4
-
-	In the above example, the option -falign-functions=4 is used for
-	gcc >= 3.00. For gcc < 3.00, -malign-functions=4 is used.
-	Note: cc-option-align uses KBUILD_CFLAGS for $(CC) options
-
     cc-disable-warning
 	cc-disable-warning checks if gcc supports a given warning and returns
 	the commandline switch to disable it. This special function is needed,
diff --git a/arch/x86/Makefile_32.cpu b/arch/x86/Makefile_32.cpu
index a45eb15b7cf2..f3717d36718a 100644
--- a/arch/x86/Makefile_32.cpu
+++ b/arch/x86/Makefile_32.cpu
@@ -9,7 +9,6 @@  else
 tune		= $(call cc-option,-mcpu=$(1),$(2))
 endif
 
-align := $(cc-option-align)
 cflags-$(CONFIG_M486)		+= -march=i486
 cflags-$(CONFIG_M586)		+= -march=i586
 cflags-$(CONFIG_M586TSC)	+= -march=i586
@@ -24,11 +23,11 @@  cflags-$(CONFIG_MK6)		+= -march=k6
 # They make zero difference whatsosever to performance at this time.
 cflags-$(CONFIG_MK7)		+= -march=athlon
 cflags-$(CONFIG_MK8)		+= $(call cc-option,-march=k8,-march=athlon)
-cflags-$(CONFIG_MCRUSOE)	+= -march=i686 $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0
-cflags-$(CONFIG_MEFFICEON)	+= -march=i686 $(call tune,pentium3) $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0
+cflags-$(CONFIG_MCRUSOE)	+= -march=i686 -falign-functions=0 -falign-jumps=0 -falign-loops=0
+cflags-$(CONFIG_MEFFICEON)	+= -march=i686 $(call tune,pentium3) -falign-functions=0 -falign-jumps=0 -falign-loops=0
 cflags-$(CONFIG_MWINCHIPC6)	+= $(call cc-option,-march=winchip-c6,-march=i586)
 cflags-$(CONFIG_MWINCHIP3D)	+= $(call cc-option,-march=winchip2,-march=i586)
-cflags-$(CONFIG_MCYRIXIII)	+= $(call cc-option,-march=c3,-march=i486) $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0
+cflags-$(CONFIG_MCYRIXIII)	+= $(call cc-option,-march=c3,-march=i486) -falign-functions=0 -falign-jumps=0 -falign-loops=0
 cflags-$(CONFIG_MVIAC3_2)	+= $(call cc-option,-march=c3-2,-march=i686)
 cflags-$(CONFIG_MVIAC7)		+= -march=i686
 cflags-$(CONFIG_MCORE2)		+= -march=i686 $(call tune,core2)
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index 5001bf9b6579..9a7697d17fb5 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -133,11 +133,6 @@  hostcc-option = $(call __cc-option, $(HOSTCC),\
 cc-option-yn = $(call try-run,\
 	$(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
 
-# cc-option-align
-# Prefix align with either -falign or -malign
-cc-option-align = $(subst -functions=0,,\
-	$(call cc-option,-falign-functions=0,-malign-functions=0))
-
 # cc-disable-warning
 # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
 cc-disable-warning = $(call try-run,\