arithmetic compressor integration to RTL MVAU - #1648
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Port of compressor-python library for efficient low-bitwidth dot product computation using LUT primitives instead of DSP blocks. Architecture: - Counter-based compressor trees - Fused accumulation with constant propagation - Target-specific primitive selection (CARRY4/CARRY8/LOOKAHEAD8) FPGA Support: - Versal: Fully functional - 7-Series: Functional without fused accumulation and gate absorption (not ready for mvau integration) - UltraScale/UltraScale+: Not yet implemented Integration scripts for both dotp_comp and add_multi optimization modes included. Implementation: - Python-based compressor graph construction and optimization - SystemVerilog template expansion for RTL generation - mul_comp_map module for partial product broadcasting This commit adds the generator infrastructure only. Integration with FINN's RTL backend follows in subsequent commits.
Wire the compressor generator into FINN's RTL MVAU datapath, enabling LUT-based dot product computation as an alternative to DSP blocks. RTL Datapath Changes (finn-rtllib/mvu/): - mvu_vvu_axi.sv: Add USE_COMPRESSOR parameter and conditional instantiation - add_multi.sv: Add CATCH_COMP macro for generated compressor module instantiation - mvu_vvu_axi_wrapper.v: Propagate COMP_PIPELINE_DEPTH parameter FINN Backend Integration (matrixvectoractivation_rtl.py): - Add compressor eligibility checks (_is_dotp_comp_eligible) - Conditionally generate dotp_comp and add_multi compressor modules - Include generated RTL files in build - Propagate USE_COMPRESSOR and COMP_PIPELINE_DEPTH template variables Versal MVAU can use compressor-based compute instead of DSP blocks. 7-Series and UltraScale+ not yet supported.
Test infrastructure: - XSim testbench templates (dotp_comp_tb, add_multi_comp_tb, mul_comp_map_tb) - Vivado TCL simulation scripts (dotp_comp, add_multi_comp, dotp) - Test runner scripts: run_tests.sh (21 core configs), run_dotp_comp_tests.sh (8 configs), run_add_multi_comp_tests.sh (8 configs) - Common test utilities (test_common.sh)
Complete 7-Series support with gate absorption optimization and fused accumulation. Add UltraScale/UltraScale+ target (reuses 7-Series primitives, Vivado maps CARRY4→CARRY8 transparently). Key Changes: - Implement 7-Series gate absorption (MuxCYPredAdder, MuxCYRippleSum) - Fix 7-Series fused accumulation and carry chain wiring - Fix compressor generation bugs (mul_comp_map indexing, N=1 passthrough, MuxCYAtom06) - Add UltraScale() target class and remove UltraScale+ restrictions - Remove RTL bitwidth restrictions: 2-3 bit networks now eligible for compressor path - Add BIPOLAR datatype guard (RTL doesn't support BIPOLAR) - Unified add_multi.sv generation for OOC synthesis - VVU template variable consistency (USE_COMPRESSOR, COMP_PIPELINE_DEPTH) All three FPGA families (Versal, 7-Series, UltraScale+) now fully supported.
…ale+ test coverage
- Fixed bitwidth >= 2 check for both activations and weights - Remove 7-Series narrow weight clipping from tests - Update comments to reflect bitwidth ranges
…e. pre-commit changes. code cleanup of several testing scripts.
…s pulled into finn.
… never overlap in the flat-namespace compile that is used.
Stage the compressor's fixed HDL at ipgen via $COMPRESSOR_ROOT/copy_sources.sh and register it from the emitted filelist.f, with add_multi.sv as a single parametric module (TARGET, CYCLE_BUDGET) and a unique per-node core name that keeps whole-design sim collision-free. Drop the compressor pip dependency and the codegen nodeattrs, simplifying add_multi_dedup and synth_ooc.
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Replaces hls dot-product and add-multi computation in RTL MVAU with fully elaboration time compressor tree implementations, reducing resource usage for low-bitwidths. supports all three FPGA families (versal, 7series and UltraScale). rtl files are based in finnlib.