[PATCH net-next 2/3] arm64: bpf: optimize JMP_CALL

From: Zi Shen Lim
Date: Sat Jun 04 2016 - 18:01:32 EST


Remove superfluous stack frame, saving us 3 instructions for
every JMP_CALL.

Signed-off-by: Zi Shen Lim <zlim.lnx@xxxxxxxxx>
---
arch/arm64/net/bpf_jit_comp.c | 3 ---
1 file changed, 3 deletions(-)

diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index 51abc97..7ae304e 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -578,11 +578,8 @@ emit_cond_jmp:
const u64 func = (u64)__bpf_call_base + imm;

emit_a64_mov_i64(tmp, func, ctx);
- emit(A64_PUSH(A64_FP, A64_LR, A64_SP), ctx);
- emit(A64_MOV(1, A64_FP, A64_SP), ctx);
emit(A64_BLR(tmp), ctx);
emit(A64_MOV(1, r0, A64_R(0)), ctx);
- emit(A64_POP(A64_FP, A64_LR, A64_SP), ctx);
break;
}
/* tail call */
--
1.9.1