https://sourceware.org/bugzilla/show_bug.cgi?id=30690
--- Comment #1 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jose E. Marchesi <jema...@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=249d4715e41061b6bd2d26df20ae274e6478f972 commit 249d4715e41061b6bd2d26df20ae274e6478f972 Author: Jose E. Marchesi <jose.march...@oracle.com> Date: Thu Jul 27 18:17:35 2023 +0200 bpf: gas: support relaxation of V4 jump instructions The BPF jump-always instruction (JA), like all other jump instructions in the ISA, get a signed 16-bit displacement target argument denoted in number of 64-bit words minus one. This can sometimes be overflown. The BPF V4 ISA thus introduced support for a jump-always instruction (JAL) that gets a signed 32-bit displacement instead. This patch makes the BPF assembler to perform the following relaxations when the disp16 field gets overflown, unless the option -mno-relax is specified: JA disp16 -> JAL disp32 Jxx disp16 -> Jxx +1; JA +1; JAL disp32 Documentation and tests added. Tested in bpf-unknown-none. gas/ChangeLog: 2023-07-28 Jose E. Marchesi <jose.march...@oracle.com> PR gas/30690 * config/tc-bpf.c (struct bpf_insn): Add fields is_relaxable and relaxed_exp. (enum options): Add OPTION_NO_RELAX. (md_longopts): Likewise for -mno-relax. (do_relax): New global. (md_parse_option): Handle OPTION_NO_RELAX. (RELAX_BRANCH_ENCODE): Define. (RELAX_BRANCH_P): Likewise. (RELAX_BRANCH_LENGTH): Likewise. (RELAX_BRANCH_CONST): Likewise. (RELAX_BRANCH_UNCOND): Likewise. (relaxed_branch_length): New function. (md_estimate_size_before_relax): Likewise. (read_insn_word): Likewise. (encode_int16): Likewise. (encode_int32): Likewise. (write_insn_bytes): Likewise. (md_convert_frag): Likewise. (encode_insn): Likewise. (install_insn_fixups): Likewise. (add_fixed_insn): Likewise. (add_relaxed_insn): Likewise. (md_assemble): Move instruction encoding logic to the above new functions. * testsuite/gas/bpf/jump-relax-ja.d: New test. * testsuite/gas/bpf/jump-relax-ja-be.d: Likewise. * testsuite/gas/bpf/jump-relax-ja.s: And corresponding source. * testsuite/gas/bpf/jump-relax-jump.d: New test. * testsuite/gas/bpf/jump-relax-jump-be.d: Likewise. * testsuite/gas/bpf/jump-relax-jump.s: And corresponding source. * testsuite/gas/bpf/bpf.exp: Run new tests. * doc/c-bpf.texi (BPF Options): Document -mno-relax. -- You are receiving this mail because: You are on the CC list for the bug.
