Re: [PATCH v2 00/52] disas/riscv: Reorganize the disassembler

On Wed, 2026-08-12 at 15:30 -0700, Richard Henderson wrote:
> One of my pet peeves is the non-automatic addition of indexes to
> rv_op
> which must match entries in rvi_opcode_data[].
> 
> Reorganize the disassembler to pass around pointers to individual
> opcodes
> rather than pointer to table + index.  To do that, rewrite how pseudo
> ops
> are processed, replacing indexes with pointers.  Merge the
> decompression
> of compressed opcodes into the pseudo ops mechanism.
> 
> Fix quite a few bugs found in the process, mostly related to isa
> level.
> 
> Changes for v2:
>   - Rebase on riscv-to-apply.next, which now contains Tiancheng's
> fixes.
>   - Adjust the DECOMP macro to make clang happy.
>   - new patch: "disas/riscv: Skip post-processing of illegal insns"
> 
> The only unreviewed patch is the new one.
> 
> 
> r~
> 
> 
> Richard Henderson (52):
>   disas/riscv: Move operand extractors earlier in file
>   disas/riscv: Reduce rv_insn to uint32_t
>   disas/riscv: Tidy dec initialization in disasm_inst
>   disas/riscv: Pass rv_opcode_data pointer to decode_inst_operands
>   disas/riscv: Pass rv_opcode_data pointer to/from
>     decode_inst_decompress
>   disas/riscv: Pass rv_opcode_data pointer to/from
>     decode_inst_lift_pseudo
>   disas/riscv: Pass rv_opcode_data pointer to format_inst
>   disas/riscv: Tidy disasm_inst main loop
>   disas/riscv: Set dec->opcode_data in decode function
>   disas/riscv: Drop explicit zero of rv_opcode_data fields
>   disas/riscv: Drop useless const in structures
>   disas/riscv: Drop codec from rv_decode
>   disas/riscv: Handle c.addi4spn imm != 0 during decode
>   disas/riscv: Simplify c.addi
>   disas/riscv: Handle c.lui imm != 0 during decode
>   disas/riscv: Handle c.{srli,srai} imm during decode
>   disas/riscv: Handle c.slli imm != 0 during decode
>   disas/riscv: Do not recognize c.{addw,subw} with rv32
>   disas/riscv: Remove rvcd_imm_nz
>   disas/riscv: Unify decomp_rv{32,64,128}
>   disas/riscv: Drop always true branch pseudos
>   disas/riscv: Handle aliases of csrrw during decode
>   disas/riscv: Handle aliases of csrrs during decode
>   disas/riscv: Handle aliases of csrrwi during decode
>   disas/riscv: Break pseudo loop for jal and jalr
>   disas/riscv: Allow decode_inst_lift_pseudo to loop
>   disas/riscv: Handle decompression via decode_inst_lift_pseudo
>   disas/riscv: Drop format from DECOMP insns
>   disas/riscv: Tidy rv_comp_data terminators
>   disas/riscv: Chain "ret" pseudo off "jr" pseudo
>   disas/riscv: Chain "nop" pseudo off "mv" pseudo
>   disas/riscv: Use rv_codec_illegal for pseudos
>   disas/riscv: Simplify some insn decompressions
>   disas/riscv: Store op pointer in rv_comp_data
>   disas/riscv: Return rv_opcode_data pointer from decoders
>   disas/riscv: Skip post-processing of illegal insns
>   disas/riscv: Reject all of OP-32 and OP-IMM-32 for RV32
>   disas/riscv: Fix rv32 encoding of zext.h
>   disas/riscv: Fix isa decoding of rev8
>   disas/riscv: Fix typo in th.lbib format
>   disas/riscv: Split ventana_opcode_data
>   disas/riscv: Split xlrbr_opcode_data
>   disas/riscv: Split xthead_opcode_data
>   disas/riscv: Move rv_op_illegal to riscv.c
>   disas/riscv: Split out riscv-op.c.inc
>   disas/riscv: Merge all mop.r.n to one pattern
>   disas/riscv: Merge all mop.rr.n to one pattern
>   disas/riscv: Merge all c.mop.n to one pattern
>   disas/riscv: Tidy decode of c.mop.n
>   disas/riscv: Tidy decode of mop.r.n and mop.rr.n
>   disas/riscv: Split rvi_opcode_data
>   disas/riscv: Sort riscv-op.c.inc

Thanks!

Applied to riscv-to-apply.next

Alistair

> 
>  disas/riscv-xlrbr.h           |    4 +-
>  disas/riscv-xthead.h          |   24 +-
>  disas/riscv-xventana.h        |    4 +-
>  disas/riscv.h                 |   46 +-
>  disas/riscv-xlrbr.c           |   57 +-
>  disas/riscv-xthead.c          |  503 +--
>  disas/riscv-xventana.c        |   23 +-
>  disas/riscv.c                 | 6390 +++++++++++--------------------
> --
>  disas/riscv-op.c.inc          |  913 +++++
>  disas/riscv-xlrbr-op.c.inc    |    8 +
>  disas/riscv-xthead-op.c.inc   |  125 +
>  disas/riscv-xventana-op.c.inc |    2 +
>  12 files changed, 3411 insertions(+), 4688 deletions(-)
>  create mode 100644 disas/riscv-op.c.inc
>  create mode 100644 disas/riscv-xlrbr-op.c.inc
>  create mode 100644 disas/riscv-xthead-op.c.inc
>  create mode 100644 disas/riscv-xventana-op.c.inc