| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 29/70] x86/kbuild: Use cc-option to enable -falign-{jumps/loops} | Date | Mon, 26 Nov 2018 11:50:44 +0100 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Matthias Kaehlcke <mka@chromium.org>
commit 2c4fd1ac3ff167c91272dc43c7bfd2269ef61557 upstream.
clang currently does not support these optimizations, only enable them when they are available.
Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Cc: Greg Hackmann <ghackmann@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michael Davidson <md@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: grundler@chromium.org Link: http://lkml.kernel.org/r/20170413172609.118122-1-mka@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- arch/x86/Makefile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -88,10 +88,10 @@ else KBUILD_CFLAGS += -m64 # Align jump targets to 1 byte, not the default 16 bytes: - KBUILD_CFLAGS += -falign-jumps=1 + KBUILD_CFLAGS += $(call cc-option,-falign-jumps=1) # Pack loops tightly as well: - KBUILD_CFLAGS += -falign-loops=1 + KBUILD_CFLAGS += $(call cc-option,-falign-loops=1) # Don't autogenerate traditional x87 instructions KBUILD_CFLAGS += $(call cc-option,-mno-80387)
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