Messages in this thread Patch in this message | | | From | Masahiro Yamada <> | Subject | [PATCH] arm64: relax assembly code alignment from 16 byte to 4 byte | Date | Thu, 31 Aug 2017 18:56:23 +0900 |
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Aarch64 instructions must be word aligned. The current 16 byte alignment is more than enough. Relax it into 4 byte alignment.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> ---
I do not know why arm64 Linux requires 16 byte alignment.
I dug git-history of arch/arm64/include/asm/linkage.h and the only commit I see is:
commit aeed41a9371ee02257b608eb06a9058507a7d0f4 Author: Marc Zyngier <Marc.Zyngier@arm.com> Date: Fri Oct 19 17:33:27 2012 +0100
arm64: fix alignment padding in assembly code
It just opt out of the asm-generic variant to remove 0x90. So, the amount of alignment might not be not optimized yet.
Please correct me if I am missing something.
arch/arm64/include/asm/linkage.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/linkage.h b/arch/arm64/include/asm/linkage.h index 636c1bc..1b26629 100644 --- a/arch/arm64/include/asm/linkage.h +++ b/arch/arm64/include/asm/linkage.h @@ -1,7 +1,7 @@ #ifndef __ASM_LINKAGE_H #define __ASM_LINKAGE_H -#define __ALIGN .align 4 -#define __ALIGN_STR ".align 4" +#define __ALIGN .align 2 +#define __ALIGN_STR ".align 2" #endif -- 2.7.4
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