netdev - [PATCH bpf-next v2 5/7] nfp: bpf: remove the trivial JSET optimization

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Message-Id: <20181220061309.28287-6-jakub.kicinski@netronome.com>
Date:   Wed, 19 Dec 2018 22:13:07 -0800
From:   Jakub Kicinski <jakub.kicinski@...ronome.com>
To:     alexei.starovoitov@...il.com, daniel@...earbox.net
Cc:     oss-drivers@...ronome.com, netdev@...r.kernel.org,
        Jakub Kicinski <jakub.kicinski@...ronome.com>
Subject: [PATCH bpf-next v2 5/7] 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 <jakub.kicinski@...ronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@...ronome.com>
---
 drivers/net/ethernet/netronome/nfp/bpf/jit.c | 5 -----
 1 file changed, 5 deletions(-)

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(),
-- 
2.19.2