Re: [PATCH v2 net-next] bpf: arm64: remove callee-save registers use for tmp registers

On Mon, May 16, 2016 at 04:36:26PM -0700, Yang Shi wrote:

In the current implementation of ARM64 eBPF JIT, R23 and R24 are used for
tmp registers, which are callee-saved registers. This leads to variable size
of JIT prologue and epilogue. The latest blinding constant change prefers to
constant size of prologue and epilogue. AAPCS reserves R9 ~ R15 for temp
registers which not need to be saved/restored during function call. So, replace
R23 and R24 to R10 and R11, and remove tmp_used flag to save 2 instructions for
some jited BPF program.

CC: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Zi Shen Lim <redacted>
Signed-off-by: Yang Shi <redacted>

Acked-by: Catalin Marinas <catalin.marinas@arm.com>