From 6e774845b321e729966fed7de4aa8ea59c2c3b2e Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Wed, 19 Dec 2018 22:13:07 -0800 Subject: nfp: bpf: remove the trivial JSET optimization The verifier will now understand the JSET instruction, so don't mark the dead branch in the JIT as noop. We won't generate any code, anyway. Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann --- drivers/net/ethernet/netronome/nfp/bpf/jit.c | 5 ----- 1 file changed, 5 deletions(-) (limited to 'drivers') diff --git a/drivers/net/ethernet/netronome/nfp/bpf/jit.c b/drivers/net/ethernet/netronome/nfp/bpf/jit.c index 662cbc21d909..f765e76e4924 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c @@ -3054,11 +3054,6 @@ static int jset_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) u64 imm = insn->imm; /* sign extend */ swreg tmp_reg; - if (!imm) { - meta->skip = true; - return 0; - } - if (imm & ~0U) { tmp_reg = ur_load_imm_any(nfp_prog, imm & ~0U, imm_b(nfp_prog)); emit_alu(nfp_prog, reg_none(), -- cgit v1.2.3 From 4987eaccd2d1535eaa72d3bbe2b8bfc8267ba965 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Wed, 19 Dec 2018 22:13:08 -0800 Subject: 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 Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann --- drivers/net/ethernet/netronome/nfp/bpf/jit.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) (limited to 'drivers') 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; } -- cgit v1.2.3