[v3,0/7] target/riscv: Add XVentanaCondOps and supporting infrastructure changes

Message

Philipp Tomsich Jan. 28, 2022, 2:56 p.m. UTC

In adding our first X-extension (i.e., vendor-defined) on RISC-V with
XVentanaCondOps, we need to add a few instructure improvements to make
it easier to add similar vendor-defined extensions in the future:
- refactor access to the cfg->ext_* fields by making a pointer to the
  cfg structure (as cfg_ptr) available via DisasContext
- add a table-based list of decoders to invoke, each being guarded by
  a guard/predicate-function, that can be used to either add vendor
  extensions, large extensions or override (by listing the decoder
  before the one for standard extensions) patterns to handle errata


Changes in v3:
- (new patch) refactor 'struct RISCVCPUConfig'
- (new patch) copy pointer to element cfg into DisasContext
- (new patch) test extension-availability through cfg_ptr in
  DisasContext, removing the fields that have been copied into
  DisasContext directly
- (new patch) change Zb[abcs] implementation to use cfg_ptr (copied
  into DisasContext) instead of going throuhg RISCV_CPU
- expose only the DisasContext* to predicate functions
- mark the table of decoder functions as static
- drop the inline from always_true_p, until the need arises (i.e.,
  someone finds a use for it and calls it directly)
- rewrite to drop the 'handled' temporary in iterating over the
  decoder table, removing the assignment in the condition of the if
- rename to trans_xventanacondops.c.inc (i.e. with the '.c')
- (in MATERIALISE_EXT_PREDICATE) don't annotate the predicate function
  for testing the availability of individual extensions as 'inline'
  and don't make CPURISCVState* visible to these predicate functions
- add a MAINTAINERS entry for XVentanaCondOps

Changes in v2:
- (new patch) iterate over a table of guarded decoder functions
- Split off decode table into XVentanaCondOps.decode
- Wire up XVentanaCondOps in the decoder-table

Philipp Tomsich (7):
  target/riscv: refactor (anonymous struct) RISCVCPU.cfg into 'struct
    RISCVCPUConfig'
  target/riscv: riscv_tr_init_disas_context: copy pointer-to-cfg into
    cfg_ptr
  target/riscv: access configuration through cfg_ptr in DisasContext
  target/riscv: access cfg structure through DisasContext
  target/riscv: iterate over a table of decoders
  target/riscv: Add XVentanaCondOps custom extension
  target/riscv: add a MAINTAINERS entry for XVentanaCondOps

 MAINTAINERS                                   |   7 ++
 target/riscv/XVentanaCondOps.decode           |  25 +++++
 target/riscv/cpu.c                            |   3 +
 target/riscv/cpu.h                            |  79 ++++++-------
 target/riscv/insn_trans/trans_rvb.c.inc       |   8 +-
 target/riscv/insn_trans/trans_rvi.c.inc       |   2 +-
 target/riscv/insn_trans/trans_rvv.c.inc       | 104 +++++++++---------
 target/riscv/insn_trans/trans_rvzfh.c.inc     |   4 +-
 .../insn_trans/trans_xventanacondops.c.inc    |  39 +++++++
 target/riscv/meson.build                      |   1 +
 target/riscv/translate.c                      |  62 +++++++----
 11 files changed, 218 insertions(+), 116 deletions(-)
 create mode 100644 target/riscv/XVentanaCondOps.decode
 create mode 100644 target/riscv/insn_trans/trans_xventanacondops.c.inc