Versions of gcc prior to gcc 5 emitted a __multi3 function call when dealing with TI types, resulting in failures when trying to link to libgcc, and more generally, horrible performance. However, since gcc 5, the compiler supports actually emitting fast instructions, which means we can at long last enable this option and receive the speedups.
The gcc commit that added proper Aarch64 support is: https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=d1ae7bb994f49316f6f63e6173f2931e837a351d This commit appears to be part of the gcc 5 release. Signed-off-by: Jason A. Donenfeld <ja...@zx2c4.com> --- arch/arm64/Makefile | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index 939b310913cf..1f8a0fec6998 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -53,6 +53,8 @@ KBUILD_AFLAGS += $(lseinstr) $(brokengasinst) KBUILD_CFLAGS += $(call cc-option,-mabi=lp64) KBUILD_AFLAGS += $(call cc-option,-mabi=lp64) +KBUILD_CFLAGS += $(call cc-ifversion, -ge, 0500, -DCONFIG_ARCH_SUPPORTS_INT128) + ifeq ($(CONFIG_CPU_BIG_ENDIAN), y) KBUILD_CPPFLAGS += -mbig-endian CHECKFLAGS += -D__AARCH64EB__ -- 2.14.2
