nfp: bpf: remove the trivial JSET optimization

Jakub Kicinski · borkmann · commit 6e774845b321 · 2018-12-20T17:28:28.000+01:00
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 &lt;jakub.kicinski@netronome.com&gt;
Reviewed-by: Quentin Monnet &lt;quentin.monnet@netronome.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
diff --git 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(),
