GCC 10 appears to have changed -O2 in order to make compilation time
faster when using -flto, seemingly at the expense of performance, in
particular with regards to how the inliner works. Since -O3 these days
shouldn't have the same set of bugs as 10 years ago, this commit
defaults new kernel compiles to -O3 when using gcc >= 10.
Signed-off-by: Jason A. Donenfeld <ja...@zx2c4.com>
---
init/Kconfig | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/init/Kconfig b/init/Kconfig
index 9e22ee8fbd75..fab3f810a68d 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1245,7 +1245,8 @@ config BOOT_CONFIG
choice
prompt "Compiler optimization level"
- default CC_OPTIMIZE_FOR_PERFORMANCE
+ default CC_OPTIMIZE_FOR_PERFORMANCE_O3 if GCC_VERSION >= 100000
+ default CC_OPTIMIZE_FOR_PERFORMANCE if (GCC_VERSION < 100000 ||
CC_IS_CLANG)
config CC_OPTIMIZE_FOR_PERFORMANCE
bool "Optimize for performance (-O2)"
--
2.26.2
