[Qemu-devel] [PATCH v5 00/35] target/riscv: Convert to decodetree

[Bastian Koppelmann <kbastian@mail.uni-paderborn.de>]

Hi,

this patchset converts the RISC-V decoder to decodetree in four major steps:

1) Convert 32-bit instructions to decodetree [Patch 1-16]:
    Many of the gen_* functions are called by the decode functions for 16-bit
    and 32-bit functions. If we move translation code from the gen_*
    functions to the generated trans_* functions of decode-tree, we get a lot of
    duplication. Therefore, we mostly generate calls to the old gen_* function
    which are properly replaced after step 2).

    Each of the trans_ functions are grouped into files corresponding to their
    ISA extension, e.g. addi which is in RV32I is translated in the file
    'trans_rvi.inc.c'.

2) Convert 16-bit instructions to decodetree [Patch 17-19]:
    All 16 bit instructions have a direct mapping to a 32 bit instruction. Thus,
    we convert the arguments in the 16 bit trans_ function to the arguments of
    the corresponding 32 bit instruction and call the 32 bit trans_ function.

3) Remove old manual decoding in gen_* function [Patch 20-30]:
    this move all manual translation code into the trans_* instructions of
    decode tree, such that we can remove the old decode_* functions.

4) Simplify RVC by reusing as much as possible from the RVG decoder as suggested
   by Richard. [Patch 31-35]

full tree available at
https://github.com/bkoppelmann/qemu/tree/riscv-dt-v5

Cheers,
Bastian

v4 -> v5:
    - fixed rebase error
    - moved TARGET_LONG_BITS check of shift instructions before rd == 0 check
    - removed extra sign extension of sraiw
    - removed rs2 == 0 special cases in sraw/srlw

Bastian Koppelmann (35):
  target/riscv: Move CPURISCVState pointer to DisasContext
  target/riscv: Activate decodetree and implemnt LUI & AUIPC
  target/riscv: Convert RVXI branch insns to decodetree
  target/riscv: Convert RV32I load/store insns to decodetree
  target/riscv: Convert RV64I load/store insns to decodetree
  target/riscv: Convert RVXI arithmetic insns to decodetree
  target/riscv: Convert RVXI fence insns to decodetree
  target/riscv: Convert RVXI csr insns to decodetree
  target/riscv: Convert RVXM insns to decodetree
  target/riscv: Convert RV32A insns to decodetree
  target/riscv: Convert RV64A insns to decodetree
  target/riscv: Convert RV32F insns to decodetree
  target/riscv: Convert RV64F insns to decodetree
  target/riscv: Convert RV32D insns to decodetree
  target/riscv: Convert RV64D insns to decodetree
  target/riscv: Convert RV priv insns to decodetree
  target/riscv: Convert quadrant 0 of RVXC insns to decodetree
  target/riscv: Convert quadrant 1 of RVXC insns to decodetree
  target/riscv: Convert quadrant 2 of RVXC insns to decodetree
  target/riscv: Remove gen_jalr()
  target/riscv: Remove manual decoding from gen_branch()
  target/riscv: Remove manual decoding from gen_load()
  target/riscv: Remove manual decoding from gen_store()
  target/riscv: Move gen_arith_imm() decoding into trans_* functions
  target/riscv: make ADD/SUB/OR/XOR/AND insn use arg lists
  target/riscv: Remove shift and slt insn manual decoding
  target/riscv: Remove manual decoding of RV32/64M insn
  target/riscv: Rename trans_arith to gen_arith
  target/riscv: Remove gen_system()
  target/riscv: Remove decode_RV32_64G()
  target/riscv: Convert @cs_2 insns to share translation functions
  target/riscv: Convert @cl_d, @cl_w, @cs_d, @cs_w insns
  target/riscv: Splice fsw_sd and flw_ld for riscv32 vs riscv64
  target/riscv: Splice remaining compressed insn pairs for riscv32 vs
    riscv64
  target/riscv: Remaining rvc insn reuse 32 bit translators

 target/riscv/Makefile.objs                    |   22 +
 target/riscv/insn16-32.decode                 |   31 +
 target/riscv/insn16-64.decode                 |   33 +
 target/riscv/insn16.decode                    |  114 ++
 target/riscv/insn32-64.decode                 |   72 +
 target/riscv/insn32.decode                    |  203 ++
 .../riscv/insn_trans/trans_privileged.inc.c   |  110 +
 target/riscv/insn_trans/trans_rva.inc.c       |  207 ++
 target/riscv/insn_trans/trans_rvc.inc.c       |  149 ++
 target/riscv/insn_trans/trans_rvd.inc.c       |  388 ++++
 target/riscv/insn_trans/trans_rvf.inc.c       |  388 ++++
 target/riscv/insn_trans/trans_rvi.inc.c       |  568 ++++++
 target/riscv/insn_trans/trans_rvm.inc.c       |  107 +
 target/riscv/translate.c                      | 1781 ++---------------
 14 files changed, 2611 insertions(+), 1562 deletions(-)
 create mode 100644 target/riscv/insn16-32.decode
 create mode 100644 target/riscv/insn16-64.decode
 create mode 100644 target/riscv/insn16.decode
 create mode 100644 target/riscv/insn32-64.decode
 create mode 100644 target/riscv/insn32.decode
 create mode 100644 target/riscv/insn_trans/trans_privileged.inc.c
 create mode 100644 target/riscv/insn_trans/trans_rva.inc.c
 create mode 100644 target/riscv/insn_trans/trans_rvc.inc.c
 create mode 100644 target/riscv/insn_trans/trans_rvd.inc.c
 create mode 100644 target/riscv/insn_trans/trans_rvf.inc.c
 create mode 100644 target/riscv/insn_trans/trans_rvi.inc.c
 create mode 100644 target/riscv/insn_trans/trans_rvm.inc.c

-- 
2.20.1