On Tue, Dec 3, 2013 at 4:35 PM, Jonathan Corbet <cor...@lwn.net> wrote: > On Mon, 2 Dec 2013 20:28:50 -0800 > Alexei Starovoitov <a...@plumgrid.com> wrote: > >> GCC-BPF backend is available on github >> (since gcc plugin infrastructure doesn't allow for out-of-tree backends) > > Do you have a pointer to where this backend can be found? I've > done a bit of digging around but seem to be unable to find it…
here it is: https://github.com/iovisor/bpf_gcc/commit/9e7223f8f09c822ecc6e18309e89a574a23dbf63 It's quite small comparing to normal backend: config.me | 3 + config.sub | 12 +- gcc/common/config/bpf/bpf-common.c | 39 ++ gcc/config.gcc | 18 + gcc/config/bpf/bpf-modes.def | 22 + gcc/config/bpf/bpf-protos.h | 60 ++ gcc/config/bpf/bpf.c | 1063 ++++++++++++++++++++++++++++++++++++ gcc/config/bpf/bpf.h | 746 +++++++++++++++++++++++++ gcc/config/bpf/bpf.md | 895 ++++++++++++++++++++++++++++++ gcc/config/bpf/linux.h | 67 +++ 10 files changed, 2922 insertions(+), 3 deletions(-) Instruction emission is in bpf.md in functions like: (define_insn "adddi3" [(set (match_operand:DI 0 "int_reg_operand" "=r, r") (plus:DI (match_operand:DI 1 "int_reg_operand" "0, 0") (match_operand:DI 2 "int_reg_or_const_operand" "r, K")))] "" "@ BPF_INSN_ALU(BPF_ADD, %0, %2), // %0 += %2 BPF_INSN_ALU_IMM(BPF_ADD, %0, %2), // %0 += %2" [(set_attr "type" "arith,arith") ]) So it takes C and emits BPF_* macros from include/linux/bpf.h tools/bpf/trace/ examples were generated by it. Eventually it will be changed to emit binary hex directly, but macros are much easier to understand for now. Thanks Alexei -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
