-O2 enables tail merging of string table strings. For arm64: 0.34% size improvement with lld -O2 over lld for vmlinux. 3.30% size improvement with lld -O2 over lld for Image.lz4-dtb. Link: https://github.com/ClangBuiltLinux/linux/issues/343 Suggested-by: Rui Ueyama <ruiu@xxxxxxxxxx> Suggested-by: Nathan Chancellor <natechancellor@xxxxxxxxx> Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> --- Makefile | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/Makefile b/Makefile index 6307c17259ea..c07208ec49d4 100644 --- a/Makefile +++ b/Makefile @@ -718,6 +718,10 @@ else KBUILD_CFLAGS += -Wno-unused-but-set-variable endif +ifdef CONFIG_LD_IS_LLD +KBUILD_LDFLAGS += -O2 +endif + KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable) ifdef CONFIG_FRAME_POINTER KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls -- 2.20.1.791.gb4d0f1c61a-goog
