[PATCH v2 00/18] target/riscv: Add support for RISC-V P

This series adds support for the RISC-V Packed SIMD (P) extension.

The P extension defines packed-SIMD fixed-point operations intended
for DSP-style workloads such as multimedia and signal processing.
These instructions operate on packed subword elements within
general-purpose registers (GPRs).

The implementation follows the current development draft of the
specification (v0.20):

  https://github.com/riscv/riscv-p-spec/
  or
  https://www.jhauser.us/RISCV/ext-P/

Compared with v1, this version reduces implementation boilerplate by
defining and reusing helper macros for common patterns in
trans_rvp.c.inc and psimd_helper.c. It also consolidates the P
extension prerequisite validation in riscv_cpu_validate_p().

The Zbkb dependency has been removed to align the implementation with
the current specification. This version also implements the
specification-defined control of vxsat, which was missing from v1.

All instructions have been functionally tested using the following
test suite:

  https://github.com/mollybuild/qemu-riscv-test-uart

The implementation focuses on functional correctness and ISA
coverage. Performance optimizations were not considered at this
stage.

Feedback on the implementation details would be highly appreciated.

Tested with:

  - ninja -C build test
  - make -C build check-qtest-riscv32
  - make -C build check-qtest-riscv64
  - Functional tests for all P extension instructions using
    qemu-riscv-test-uart

No regressions or test failures were observed.

---
Changes in v2:

  - Refactored trans_rvp.c.inc and psimd_helper.c by defining and
    reusing helper macros for common implementation patterns, reducing
    boilerplate and overall code size.
  - Moved the P extension prerequisite checks into
    riscv_cpu_validate_p().
  - Removed the Zbkb dependency to align with the current
    specification.
  - Added the specification-defined vxsat control mechanism, which was
    missing from v1.

v1:
  https://lists.nongnu.org/archive/html/qemu-riscv/2026-04/msg00301.html

Molly Chen (18):
  target/riscv: Add packed SIMD extension state
  target/riscv: Add packed SIMD helper framework
  target/riscv: Add packed SIMD arithmetic instructions
  target/riscv: Add packed SIMD averaging and rounding instructions
  target/riscv: Add packed SIMD absolute, difference, compare and mask
    instructions
  target/riscv: Add packed SIMD shift instructions
  target/riscv: Add packed SIMD exchange instructions
  target/riscv: Add packed SIMD horizontal reduction instructions
  target/riscv: Add packed SIMD pack, merge and count-leading
    instructions
  target/riscv: Add packed SIMD multiplication instructions
  target/riscv: Add packed SIMD multiply-accumulate instructions
  target/riscv: Add packed SIMD Q-format multiplication instructions
  target/riscv: Add packed SIMD Q-format MAC instructions
  target/riscv: Add packed SIMD two-way MAC instructions
  target/riscv: Add packed SIMD four-way MAC instructions
  target/riscv: Add packed SIMD load-replicate instructions
  target/riscv: Add packed SIMD RV32 only instructions
  target/riscv: Remove Zbkb dependency from P extension to align with
    the spec

 target/riscv/cpu.c                          |    5 +-
 target/riscv/cpu.h                          |    8 +
 target/riscv/cpu_bits.h                     |    2 +
 target/riscv/helper.h                       |  529 ++++
 target/riscv/insn32.decode                  |  829 +++++
 target/riscv/machine.c                      |   19 +
 target/riscv/tcg/csr.c                      |   39 +-
 target/riscv/tcg/insn_trans/trans_rvb.c.inc |    4 +-
 target/riscv/tcg/insn_trans/trans_rvp.c.inc | 1389 ++++++++
 target/riscv/tcg/meson.build                |    3 +-
 target/riscv/tcg/psimd_helper.c             | 3165 +++++++++++++++++++
 target/riscv/tcg/tcg-cpu.c                  |   46 +
 target/riscv/tcg/translate.c                |    6 +
 13 files changed, 6038 insertions(+), 6 deletions(-)
 create mode 100644 target/riscv/tcg/insn_trans/trans_rvp.c.inc
 create mode 100644 target/riscv/tcg/psimd_helper.c


base-commit: 8fb307591625731060d399aca42373c02c7cb040
-- 
2.34.1