[RFC] [PATCH] arch: x86: change GCC optimisation target from atom to bonnell

[Rui Salvaterra <rsalvaterra@gmail.com>]

Hi, Thomas, Ingo, Peter,

(Sending as RFC, since I don't know if this patch is acceptable.)

The GCC team has deprecated atom as a march/mtune target since almost three
years ago, according to this mailing list thread [1], in favour of specific
microarchitecture names (bonnell, silvermont). This patch changes the Atom
optimisation target in the kernel to bonnell, as it was originally intended.

Tested on an x86-64 Atom 330 machine. No functional changes.

[1] https://gcc.gnu.org/ml/gcc-patches/2013-12/msg01805.html

Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
---
 arch/x86/Makefile        | 4 ++--
 arch/x86/Makefile_32.cpu | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 2d44933..b7d615f 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -109,8 +109,8 @@ else
 
         cflags-$(CONFIG_MCORE2) += \
                 $(call cc-option,-march=core2,$(call cc-option,-mtune=generic))
-	cflags-$(CONFIG_MATOM) += $(call cc-option,-march=atom) \
-		$(call cc-option,-mtune=atom,$(call cc-option,-mtune=generic))
+	cflags-$(CONFIG_MATOM) += $(call cc-option,-march=bonnell) \
+		$(call cc-option,-mtune=bonnell,$(call cc-option,-mtune=generic))
         cflags-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=generic)
         KBUILD_CFLAGS += $(cflags-y)
 
diff --git a/arch/x86/Makefile_32.cpu b/arch/x86/Makefile_32.cpu
index 6647ed4..d66e5e3 100644
--- a/arch/x86/Makefile_32.cpu
+++ b/arch/x86/Makefile_32.cpu
@@ -32,8 +32,8 @@ cflags-$(CONFIG_MCYRIXIII)	+= $(call cc-option,-march=c3,-march=i486) $(align)-f
 cflags-$(CONFIG_MVIAC3_2)	+= $(call cc-option,-march=c3-2,-march=i686)
 cflags-$(CONFIG_MVIAC7)		+= -march=i686
 cflags-$(CONFIG_MCORE2)		+= -march=i686 $(call tune,core2)
-cflags-$(CONFIG_MATOM)		+= $(call cc-option,-march=atom,$(call cc-option,-march=core2,-march=i686)) \
-	$(call cc-option,-mtune=atom,$(call cc-option,-mtune=generic))
+cflags-$(CONFIG_MATOM)		+= $(call cc-option,-march=bonnell,$(call cc-option,-march=core2,-march=i686)) \
+	$(call cc-option,-mtune=bonnell,$(call cc-option,-mtune=generic))
 
 # AMD Elan support
 cflags-$(CONFIG_MELAN)		+= -march=i486
-- 
2.10.1