kbuild,arc: add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3 for ARC
arch/arc/Makefile overrides -O2 with -O3. This is the only user of
ARCH_CFLAGS. There is no user of ARCH_CPPFLAGS or ARCH_AFLAGS.
My plan is to remove ARCH_{CPP,A,C}FLAGS after refactoring the ARC
Makefile.
Currently, ARC has no way to enable -Wmaybe-uninitialized because both
-O3 and -Os disable it. Enabling it will be useful for compile-testing.
This commit allows allmodconfig (, which defaults to -O2) to enable it.
Add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y to all the defconfig files
in arch/arc/configs/ in order to keep the current config settings.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
diff --git a/init/Kconfig b/init/Kconfig
index 149efd8..9211850 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1209,14 +1209,22 @@
default CC_OPTIMIZE_FOR_PERFORMANCE
config CC_OPTIMIZE_FOR_PERFORMANCE
- bool "Optimize for performance"
+ bool "Optimize for performance (-O2)"
help
This is the default optimization level for the kernel, building
with the "-O2" compiler flag for best performance and most
helpful compile-time warnings.
+config CC_OPTIMIZE_FOR_PERFORMANCE_O3
+ bool "Optimize more for performance (-O3)"
+ depends on ARC
+ imply CC_DISABLE_WARN_MAYBE_UNINITIALIZED # avoid false positives
+ help
+ Choosing this option will pass "-O3" to your compiler to optimize
+ the kernel yet more for performance.
+
config CC_OPTIMIZE_FOR_SIZE
- bool "Optimize for size"
+ bool "Optimize for size (-Os)"
imply CC_DISABLE_WARN_MAYBE_UNINITIALIZED # avoid false positives
help
Choosing this option will pass "-Os" to your compiler resulting