[PATCH v2 00/27] Adding partial support for 128-bit riscv target

[Frédéric Pétrot]

This series of patches provides partial 128-bit support for the riscv
target architecture.
Feedback on v1 was most useful and led to many improvements.
+ the load and store make use of a not yet upstreamed patch from Richard,
+ use of the existing Int128 computations in helpers, and addition of
  a few more operations there, in particular division and remainder
+ refactoring of the calls to the code generation helpers, as suggested
  by Richard, lead to a much cleaner solution. I did that for gen_arith
  and gen_shift, not for gen_unary as it used only for the bitmanip
  extension that I did not take into consideration yet
+ split of the patch in smaller pieces, as advised by Alistair

Two things suggested I could not achieve:
- the total eviction of the #ifdefs taking the target size into account:
  I cheated by using #else when I needed, IMHO a shame
- the qemu_build_not_reached() use when accessing the upper part of the
  registers: the misa/misah field is used for this check, and in 128-bit
  the compiler cannot infer that the field is read only.

The checks I made in between each patch:
* smooth boot of busybear linux on rv64
* correct execution of all riscv-probe programs on rv32

For the 128-bit, the tests are there: https://github.com/fpetrot/128-test
* from hash 925e1af2c7, run the tests in unit_test_i
* from hash 6d4a39f2c4, run in addition the tests in unit_test_m
* from hash 864e563916, run in addition the tests unit_test_csr


Frédéric Pétrot (27):
  memory: add a few defines for octo (128-bit) values
  Int128.h: addition of a few 128-bit operations
  target/riscv: adding upper 64 bits for misa
  target/riscv: array for the 64 upper bits of 128-bit registers
  target/riscv: additional macros to check instruction support
  target/riscv: separation of bitwise logic and aritmetic helpers
  target/riscv: refactoring calls to gen_arith
  target/riscv: refactoring calls to gen_shift
  target/riscv: setup everything so that riscv128-softmmu compiles
  target/riscv: adding accessors to the registers upper part
  target/riscv: handling 128-bit part in logic/arith/shift gen helpers
  target/riscv: moving some insns close to similar insns
  target/riscv: rename a few gen function helpers
  target/riscv: 128-bit support for instructions using
    gen_arith/gen_logic
  target/riscv: 128-bit support for instructions using gen_shift
  target/riscv: support for 128-bit loads and store
  target/riscv: 128-bit double word integer arithmetic instructions
  target/riscv: 128-bit double word integer shift instructions
  target/riscv: support for 128-bit base multiplications insns
  target/riscv: addition of the 'd' insns for 128-bit mult/div/rem
  target/riscv: div and rem insns on 128-bit
  target/riscv: adding high part of some csrs
  target/riscv: helper functions to wrap calls to 128-bit csr insns
  target/riscv: modification of the trans_csrxx for 128-bit support
  target/riscv: actual functions to realize crs 128-bit insns
  target/riscv: adding 128-bit access functions for some csrs
  target/riscv: support for 128-bit satp

 configs/devices/riscv128-softmmu/default.mak |  17 +
 configs/targets/riscv128-softmmu.mak         |   6 +
 include/exec/memop.h                         |   6 +
 include/hw/riscv/sifive_cpu.h                |   3 +
 include/qemu/int128.h                        | 264 ++++++
 target/riscv/cpu-param.h                     |  10 +
 target/riscv/cpu.h                           |  40 +
 target/riscv/cpu_bits.h                      |  11 +
 target/riscv/helper.h                        |   9 +
 target/riscv/insn16.decode                   |  32 +-
 target/riscv/insn32.decode                   |  25 +
 target/riscv/cpu.c                           |  49 +-
 target/riscv/cpu_helper.c                    |  54 +-
 target/riscv/csr.c                           | 329 ++++++-
 target/riscv/gdbstub.c                       |   3 +
 target/riscv/m128_helper.c                   | 109 +++
 target/riscv/op_helper.c                     |  44 +
 target/riscv/translate.c                     | 351 ++++++-
 target/riscv/insn_trans/trans_rvb.c.inc      |  80 +-
 target/riscv/insn_trans/trans_rvd.c.inc      |  12 +-
 target/riscv/insn_trans/trans_rvf.c.inc      |   6 +-
 target/riscv/insn_trans/trans_rvi.c.inc      | 936 ++++++++++++++++---
 target/riscv/insn_trans/trans_rvm.c.inc      | 352 ++++++-
 gdb-xml/riscv-128bit-cpu.xml                 |  48 +
 gdb-xml/riscv-128bit-virtual.xml             |  12 +
 target/riscv/Kconfig                         |   3 +
 target/riscv/meson.build                     |   1 +
 27 files changed, 2579 insertions(+), 233 deletions(-)
 create mode 100644 configs/devices/riscv128-softmmu/default.mak
 create mode 100644 configs/targets/riscv128-softmmu.mak
 create mode 100644 target/riscv/m128_helper.c
 create mode 100644 gdb-xml/riscv-128bit-cpu.xml
 create mode 100644 gdb-xml/riscv-128bit-virtual.xml

-- 
2.33.0