diff options
| author | Jakub Kicinski <jakub.kicinski@netronome.com> | 2018-12-19 22:13:08 -0800 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2018-12-20 17:28:29 +0100 |
| commit | 4987eaccd2d1535eaa72d3bbe2b8bfc8267ba965 (patch) | |
| tree | c6bf58bba8b67edb2e6d80671348a54890966eef /drivers/net/ethernet/netronome/nfp/bpf/jit.c | |
| parent | 6e774845b321e729966fed7de4aa8ea59c2c3b2e (diff) | |
| download | linux-4987eaccd2d1535eaa72d3bbe2b8bfc8267ba965.tar.bz2 | |
nfp: bpf: optimize codegen for JSET with a constant
The top word of the constant can only have bits set if sign
extension set it to all-1, therefore we don't really have to
mask the top half of the register. We can just OR it into
the result as is.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'drivers/net/ethernet/netronome/nfp/bpf/jit.c')
| -rw-r--r-- | drivers/net/ethernet/netronome/nfp/bpf/jit.c | 22 |
1 files changed, 10 insertions, 12 deletions
diff --git a/drivers/net/ethernet/netronome/nfp/bpf/jit.c b/drivers/net/ethernet/netronome/nfp/bpf/jit.c index f765e76e4924..e23ca90289f7 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c @@ -3052,21 +3052,19 @@ static int jset_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) { const struct bpf_insn *insn = &meta->insn; u64 imm = insn->imm; /* sign extend */ + u8 dst_gpr = insn->dst_reg * 2; swreg tmp_reg; - if (imm & ~0U) { - tmp_reg = ur_load_imm_any(nfp_prog, imm & ~0U, imm_b(nfp_prog)); - emit_alu(nfp_prog, reg_none(), - reg_a(insn->dst_reg * 2), ALU_OP_AND, tmp_reg); - emit_br(nfp_prog, BR_BNE, insn->off, 0); - } - - if (imm >> 32) { - tmp_reg = ur_load_imm_any(nfp_prog, imm >> 32, imm_b(nfp_prog)); + tmp_reg = ur_load_imm_any(nfp_prog, imm & ~0U, imm_b(nfp_prog)); + emit_alu(nfp_prog, imm_b(nfp_prog), + reg_a(dst_gpr), ALU_OP_AND, tmp_reg); + /* Upper word of the mask can only be 0 or ~0 from sign extension, + * so either ignore it or OR the whole thing in. + */ + if (imm >> 32) emit_alu(nfp_prog, reg_none(), - reg_a(insn->dst_reg * 2 + 1), ALU_OP_AND, tmp_reg); - emit_br(nfp_prog, BR_BNE, insn->off, 0); - } + reg_a(dst_gpr + 1), ALU_OP_OR, imm_b(nfp_prog)); + emit_br(nfp_prog, BR_BNE, insn->off, 0); return 0; } |