diff options
| author | Alexei Starovoitov <ast@kernel.org> | 2022-10-19 16:53:51 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2022-10-19 16:53:51 -0700 |
| commit | 04a8f9d7c09d04ba39e84611adfe6f48e30353c3 (patch) | |
| tree | 3de533d16556810b08caba926d43effd89c62a45 /scripts/bpf_doc.py | |
| parent | 7d8d535546a0ac03d7949881ef23bd2c903d19be (diff) | |
| parent | 8662de2321496499a21841486660817f72ac9456 (diff) | |
Merge branch 'bpf,x64: Use BMI2 for shifts'
Jie Meng says:
====================
With baseline x64 instruction set, shift count can only be an immediate
or in %cl. The implicit dependency on %cl makes it necessary to shuffle
registers around and/or add push/pop operations.
BMI2 provides shift instructions that can use any general register as
the shift count, saving us instructions and a few bytes in most cases.
Suboptimal codegen when %ecx is source and/or destination is also
addressed and unnecessary instructions are removed.
test_progs: Summary: 267/1340 PASSED, 25 SKIPPED, 0 FAILED
test_progs-no_alu32: Summary: 267/1333 PASSED, 26 SKIPPED, 0 FAILED
test_verifier: Summary: 1367 PASSED, 636 SKIPPED, 0 FAILED (same result
with or without BMI2)
test_maps: OK, 0 SKIPPED
lib/test_bpf:
test_bpf: Summary: 1026 PASSED, 0 FAILED, [1014/1014 JIT'ed]
test_bpf: test_tail_calls: Summary: 10 PASSED, 0 FAILED, [10/10 JIT'ed]
test_bpf: test_skb_segment: Summary: 2 PASSED, 0 FAILED
---
v4 -> v5:
- More comments regarding instruction encoding
v3 -> v4:
- Fixed a regression when BMI2 isn't available
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'scripts/bpf_doc.py')
0 files changed, 0 insertions, 0 deletions