MSDF Online Softmax Backend

This repository contains the current MSDF online Softmax/PV backend work.

The main design target is a row-wise Softmax/PV backend:

FP32 score tile + FP16 V tile -> FP16 O

The main RTL line is:

MSDF_online_softmax_composite/rtl/msdf_online_flash_softmax_backend_ring.v

The current paper-facing configuration is the ring-reused, shared-denominator, FP-visible backend under MSDF_online_softmax_composite/. The repository also contains the PWL baseline RTL, CPU/GPU benchmark scripts and reports, and the Chinese/English paper workspace under MSDF_online_softmax_composite/Paper/.

Contents

• MSDF_online_softmax_composite/rtl/: MSDF backend, PWL baseline, wrappers, online divider, ring slot, and supporting datapaths.
• MSDF_online_softmax_composite/tb/: Verilog testbenches.
• MSDF_online_softmax_composite/model/: mathematical and vector-generation models.
• MSDF_online_softmax_composite/generated/: lightweight generated reports and test vectors. Heavy Vivado route/synth directories are intentionally excluded.
• MSDF_online_softmax_composite/Paper/: FPT-style paper drafts, figures, experiment scripts, CPU/GPU test reports, and generated tables.
• MSDF_exp_model/: minimal PWL baseline dependencies required by the composite backend scripts.

Main Experiments

• MSDF ring backend route/resource sweeps for TL64 and V channel counts 1/2/4/8.
• Matched PWL+DSP baseline sweeps.
• RTL accuracy sweeps for 2 to 1024 inputs.
• CPU single-row online Softmax/PV benchmarks on Ryzen 9950X.
• GPU single-row Softmax/PV benchmark scripts and recorded results.

Primary reports are in:

MSDF_online_softmax_composite/Paper/generated/
MSDF_online_softmax_composite/Paper/GPU_test/

Toolchain

The default FPGA toolchain is Vivado/Vitis 2023.2. On the development machine:

source /tools/Xilinx/Vitis/2023.2/settings64.sh

Route scripts are Tcl batch flows, for example:

vivado -mode batch -source MSDF_online_softmax_composite/route_online_flash_softmax_backend_ring.tcl
vivado -mode batch -source MSDF_online_softmax_composite/route_pwl_flash_softmax_backend_fpwrap.tcl

Repository Hygiene

This public snapshot intentionally excludes:

• Vivado route/synth work directories;
• .dcp, .vvp, .wdb, .jou, verbose .log, and other rebuildable tool artifacts;
• local external reference PDFs and translated paper sources.

The excluded files are either very large, machine-specific, or external reference material. The committed Markdown/CSV/JSON reports keep the numerical results needed for paper writing and review.