github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-09-24 06:24:02 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

LoongArch: BPF: Remove dead move_imm() call in BPF_NEG path

Browse Source 
The BPF_NEG operation is a unary operator that performs `dst = -dst`.
The current code unconditionally executes a move_imm() call before the
subtraction, generating useless JITted instructions to load data into
the temporary register `t1`. This `t1` register is never used anywhere
else in the entire BPF_NEG path.

Remove this dead `move_imm()` call to avoid useless instructions.

Acked-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
This commit is contained in:
Tiezhu Yang 2026-08-17 22:07:24 +08:00 committed by Huacai Chen
parent 32a5e3eaa0
commit 252ae40ba9
1 changed files with 0 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/loongarch/net/bpf_jit.c
View File

@ -869,7 +869,6 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
/* dst = -dst */
case BPF_ALU | BPF_NEG:
case BPF_ALU64 | BPF_NEG:
move_imm(ctx, t1, imm, is32);
emit_insn(ctx, subd, dst, LOONGARCH_GPR_ZERO, dst);
emit_zext_32(ctx, dst, is32);
break;