RISC-V: Control fence.i and csr instructions by zifencei and zicsr.
bfd/
* elfxx-riscv.c (riscv_ext_dont_care_version): New function. Return
TRUE if we don't care the versions of the extensions. These extensions
are added to the subset list for special purposes, with the explicit
versions or the RISCV_UNKNOWN_VERSION versions.
(riscv_parse_add_subset): If we do care the versions of the extension,
and the versions are unknown, then report errors for the non-implicit
extensions, and return directly for the implicit one.
(riscv_arch_str1): Do not output i extension after e, and the extensions
which versions are unknown.
gas/
* config/tc-riscv.c (riscv_multi_subset_supports): Handle INSN_CLASS_ZICSR
and INSN_CLASS_ZIFENCEI.
* testsuite/gas/riscv/march-imply-i.s: New testcase.
* testsuite/gas/riscv/march-imply-i2p0-01.d: New testcase. The version
of i is less than 2.1, and zi* are supported in the chosen spec, so
enable the fence.i and csr instructions, also output the implicit zi* to
the arch string.
* testsuite/gas/riscv/march-imply-i2p0-02.d: Likewise, but the zi* are
not supported in the spec 2.2. Enable the related instructions since
i's version is less than 2.1, but do not output them.
* testsuite/gas/riscv/march-imply-i2p1-01.d: New testcase. The version
of i is 2.1, so don't add it's implicit zi*, and disable the related
instructions.
* testsuite/gas/riscv/march-imply-i2p1-01.l: Likewise.
* testsuite/gas/riscv/march-imply-i2p1-02.d: Likewise, and set the zi*
explicitly, so enable the related instructions.
* testsuite/gas/riscv/march-imply-i2p0.d: Removed.
* testsuite/gas/riscv/march-imply-i2p1.d: Removed.
include/
* opcode/riscv.h: Add INSN_CLASS_ZICSR and INSN_CLASS_ZIFENCEI.
opcodes/
* riscv-opc.c (riscv_opcodes): Control fence.i and csr instructions by
zifencei and zicsr.