Ventana Micro has published the specification for their
XVentanaCondOps ("conditional ops") extension at
https://github.com/ventanamicro/ventana-custom-extensions/releases/download/v1.0.0/ventana-custom-extensions-v1.0.0.pdf
which contains two new instructions
- vt.maskc
- vt.maskcn
that can be used in constructing branchless sequences for
various conditional-arithmetic, conditional-logical, and
conditional-select operations.
To support such vendor-defined instructions in the mainline binutils,
this change also adds a riscv_supported_vendor_x_ext secondary
dispatch table (but also keeps the behaviour of allowing any unknow
X-extension to be specified in addition to the known ones from this
table).
As discussed, this change already includes the planned/agreed future
requirements for X-extensions (which are likely to be captured in the
riscv-toolchain-conventions repository):
- a public specification document is available (see above) and is
referenced from the gas-documentation
- the naming follows chapter 27 of the RISC-V ISA specification
- instructions are prefixed by a vendor-prefix (vt for Ventana)
to ensure that they neither conflict with future standard
extensions nor clash with other vendors
bfd/ChangeLog:
* elfxx-riscv.c (riscv_get_default_ext_version): Add riscv_supported_vendor_x_ext.
(riscv_multi_subset_supports): Recognize INSN_CLASS_XVENTANACONDOPS.
gas/ChangeLog:
* doc/c-riscv.texi: Add section to list custom extensions and
their documentation URLs.
* testsuite/gas/riscv/x-ventana-condops.d: New test.
* testsuite/gas/riscv/x-ventana-condops.s: New test.
include/ChangeLog:
* opcode/riscv-opc.h Add vt.maskc and vt.maskcn.
* opcode/riscv.h (enum riscv_insn_class): Add INSN_CLASS_XVENTANACONDOPS.
opcodes/ChangeLog:
* riscv-opc.c: Add vt.maskc and vt.maskcn.
Series-version: 1
Series-to: binutils@sourceware.org
Series-cc: Kito Cheng <kito.cheng@sifive.com>
Series-cc: Nelson Chu <nelson.chu@sifive.com>
Series-cc: Greg Favor <gfavor@ventanamicro.com>
Series-cc: Christoph Muellner <cmuellner@gcc.gnu.org>
1656d3f8ef