From 2c4fd1ac3ff167c91272dc43c7bfd2269ef61557 Mon Sep 17 00:00:00 2001
From: Matthias Kaehlcke <mka@chromium.org>
Date: Thu, 13 Apr 2017 10:26:09 -0700
Subject: [PATCH] x86/kbuild: Use cc-option to enable -falign-{jumps/loops}
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>
---
arch/x86/Makefile | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index a94a4d10f2df..73604e18447a 100644
--- 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)