[PATCH] test_bpf: Add a couple of tests for BPF_JSGE.

[David Daney]

Some JITs can optimize comparisons with zero.  Add a couple of
BPF_JSGE tests against immediate zero.

Signed-off-by: David Daney <david.da...@cavium.com>
---
 lib/test_bpf.c | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index 889bc31..be88cba 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -4504,6 +4504,44 @@ static struct bpf_test tests[] = {
                { },
                { { 0, 1 } },
        },
+       {
+               "JMP_JSGE_K: Signed jump: value walk 1",
+               .u.insns_int = {
+                       BPF_ALU32_IMM(BPF_MOV, R0, 0),
+                       BPF_LD_IMM64(R1, -3),
+                       BPF_JMP_IMM(BPF_JSGE, R1, 0, 6),
+                       BPF_ALU64_IMM(BPF_ADD, R1, 1),
+                       BPF_JMP_IMM(BPF_JSGE, R1, 0, 4),
+                       BPF_ALU64_IMM(BPF_ADD, R1, 1),
+                       BPF_JMP_IMM(BPF_JSGE, R1, 0, 2),
+                       BPF_ALU64_IMM(BPF_ADD, R1, 1),
+                       BPF_JMP_IMM(BPF_JSGE, R1, 0, 1),
+                       BPF_EXIT_INSN(),                /* bad exit */
+                       BPF_ALU32_IMM(BPF_MOV, R0, 1),  /* good exit */
+                       BPF_EXIT_INSN(),
+               },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+       },
+       {
+               "JMP_JSGE_K: Signed jump: value walk 2",
+               .u.insns_int = {
+                       BPF_ALU32_IMM(BPF_MOV, R0, 0),
+                       BPF_LD_IMM64(R1, -3),
+                       BPF_JMP_IMM(BPF_JSGE, R1, 0, 4),
+                       BPF_ALU64_IMM(BPF_ADD, R1, 2),
+                       BPF_JMP_IMM(BPF_JSGE, R1, 0, 2),
+                       BPF_ALU64_IMM(BPF_ADD, R1, 2),
+                       BPF_JMP_IMM(BPF_JSGE, R1, 0, 1),
+                       BPF_EXIT_INSN(),                /* bad exit */
+                       BPF_ALU32_IMM(BPF_MOV, R0, 1),  /* good exit */
+                       BPF_EXIT_INSN(),
+               },
+               INTERNAL,
+               { },
+               { { 0, 1 } },
+       },
        /* BPF_JMP | BPF_JGT | BPF_K */
        {
                "JMP_JGT_K: if (3 > 2) return 1",
-- 
2.9.4