[PATCH] Kconfig: default to CC_OPTIMIZE_FOR_PERFORMANCE_O3 for gcc >= 10

["Jason A. Donenfeld" <Jason@zx2c4.com>]

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 <Jason@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