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docs(docs): update documentation for GF16 DLFloat attribution (#477)
- Clarify GF16 adopts IBM DLFloat format (1/6/9, bias=31) - Add Agrawal 2019 and Mellempudi 2021 references - Remove φ-optimality as scientific claim (present as theoretical framework) - Note novelty is in implementation (integer-backed u16) Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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README.md

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**Honest comparison of Trinity number formats (GF16, Ternary) against IEEE standards (fp16, bfloat16).**
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**Note on GF16 Attribution:** GF16 adopts IBM's DLFloat format specification (1/6/9, bias=31) first proposed in Agrawal et al. (2019). The novelty of GF16 is its **integer-backed implementation** using `u16` storage, which bypasses 62+ compiler bugs in half-precision floating-point and provides stable cross-platform compilation.
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### Summary Table (CPU, Synthetic Data)
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| Format | Bits (s/e/m) | Range | MSE (N(0,1)) | Add (ns/op) | Mul (ns/op) | NN Accuracy | Bytes/weight |
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|----------|-------------|---------------|--------------|-------------|-------------|-------------|--------------|
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| f32 | 1/8/23 | ±3.4e38 | baseline | ~5.0 | ~4.5 | 5.80% | 32 |
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| fp16 | 1/5/10 | ±6.55e4 | 0.000123 | ~8.5 | ~4.5 | 5.80% | 16 |
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| bfloat16 | 1/8/7 | ±3.4e38 | 0.000456 |||| 16 |
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| **GF16** | **1/6/9** | **±4.29e9** | **0.000234** | **~7.2** | **~4.5** | **5.80%** | **16** |
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| **GF16** (DLFloat 6:9) | **1/6/9** | **±4.29e9** | **0.000234** | **~7.2** | **~4.5** | **5.80%** | **16** |
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| ternary | 2 bits | {-1, 0, +1} | 0.500000 | ~0.5 | ~0.5 | 6.90% | 2 |
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GF16 maintains f32-equivalent accuracy on a small MLP while offering 10⁵× wider
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dynamic range than fp16 and stable cross-platform compilation via integer-backed u16.
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GF16 (DLFloat 6:9) maintains f32-equivalent accuracy on a small MLP while offering 10⁵× wider
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dynamic range than fp16. GF16 is an **integer-backed implementation of IBM's DLFloat format** (Agrawal et al., 2019; Mellempudi et al., 2021).
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### Key Findings
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| **BENCH-001** | Quantization error (MSE/MAE) on Normal/Log-normal/Uniform distributions | ✅ Complete |
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| **BENCH-002** | Arithmetic throughput (add/mul/div) | ✅ Complete |
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| **BENCH-003** | NN inference accuracy on frozen weights | ✅ Complete |
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| **BENCH-004** | MNIST real data validation | ✅ GF16 encode/decode, trained weights support |
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### Running Benchmarks
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```bash
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# Build and run
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# Build and run (Phase 1: synthetic data)
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zig build bench-quant && ./zig-out/bin/bench-quant
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zig build bench-arith && ./zig-out/bin/bench-arith
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zig build bench-nn && ./zig-out/bin/bench-nn
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# Phase 2: MNIST real data (requires download)
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# 1. Download MNIST test data:
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cd data
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curl -LO https://ossci-datasets.s3.amazonaws.com/mnist/t10k-images-idx3-ubyte.gz
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curl -LO https://ossci-datasets.s3.amazonaws.com/mnist/t10k-labels-idx1-ubyte.gz
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gunzip t10k-images-idx3-ubyte.gz t10k-labels-idx1-ubyte.gz
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cd ..
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# 2. Run with random weights (sanity check):
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zig build bench-mnist && ./.zig-cache/o/*/bench-mnist
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# 3. Run with trained weights:
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# (Export from PyTorch using format in docs/research/gf16_vs_literature.md)
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zig build bench-mnist && ./.zig-cache/o/*/bench-mnist --weights=mnist_mlp_784x128x10.bin
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# or: ./zig-out/bin/bench-mnist
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# Results written to results/
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ls results/quant_*.csv results/arith_*.csv results/nn_*.csv
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ls results/quant_*.csv results/arith_*.csv results/nn_*.csv results/mnist_*.csv
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```
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### Documentation

docs/docs/concepts/native-f16-comparison.md

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- CPU **has** fp16 hardware → direct instructions
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- CPU **lacks** fp16 → LLVM promotes `half → float`
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**GF16 CANNOT pass natively** LLVM doesn't know "6-bit exp + 9-bit mant" type. Must use manual encode/decode at Level 0.
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**Note on GF16:** GF16 adopts IBM's DLFloat format (1/6/9, bias=31, Agrawal et al. 2019). GF16 CANNOT pass natively through LLVM — the compiler doesn't know this custom format. Must use manual encode/decode at Level 0 via integer-backed `u16` storage.
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**Source:** [LLVM SelectionDAG](https://www.cl.cam.ac.uk/teaching/1314/L25/4LLVMIRandTransformPipeline.pdf)
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| Level | What Trinity Does | File/Tool |
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|-------|-------------------|-----------|
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| **0 — Language** | GF16, TF3, Sensation System | `intraparietal_sulcus.zig`, `angular_gyrus.zig` |
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| **0 — Language** | GF16 (DLFloat 6:9), TF3, Sensation System | `intraparietal_sulcus.zig`, `angular_gyrus.zig` |
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| **1 — Frontend** | Zig compiler → ZIR | `zig build` |
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| **2 — LLVM IR** | Auto-vectorization f16 | `std.simd``<N x half>` |
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| **3 — SelectionDAG** | fp16 legalization | Automatic by LLVM |
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| **6 — RTL** | **GF16/TF3 native arithmetic** | FPGA XC7A100T (Vivado) |
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| **7 — Physical** | 28nm Artix-7 fabric | Hardware (fixed) |
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**Key insight:** Trinity operates **simultaneously** on Level 0 (language/formats) **AND** Level 6 (FPGA RTL). All others (PyTorch, JAX, TensorRT) stop at Level 0–4.
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**Key insight:** Trinity operates **simultaneously** on Level 0 (language/formats) **AND** Level 6 (FPGA RTL). All others (PyTorch, JAX, TensorRT) stop at Level 0–4. GF16 is an integer-backed implementation of IBM's DLFloat (1/6/9, bias=31).
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docs/docs/concepts/phi-distance-formats.md

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## Attribution Note
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**GF16 and IBM DLFloat:** GF16 adopts IBM's DLFloat format (1/6/9, bias=31). IBM arrived at the 1/6/9 allocation through **distribution analysis of neural network data** (Mellempudi et al., 2021), not through golden ratio optimization. φ-distance analysis here is presented as an **alternative theoretical framework** for evaluating floating-point formats, not as the design rationale for DLFloat/GF16.
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The 6/9 exponent/mantissa split happens to have good φ-distance properties (0.049), but this is **correlation, not causation**. IBM's design was based on empirical analysis of deep learning workloads, not sacred geometry.
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---
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## Executive Summary
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Standard floating-point formats (IEEE 754) were chosen by committees, not mathematical principles. This analysis shows that **custom formats (GF16, TF3) are closer to φ** than any standard format, suggesting they may be more "naturally suited" for representing real-world data.

docs/research/bundles/B006_GF16.md

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## Overview
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**Note on GF16 Format Attribution:** GF16 adopts IBM's DLFloat format (1/6/9, bias=31), first proposed in Agrawal et al. (2019). This is an **integer-backed implementation** of IBM's format using `u16` storage, providing cross-platform stability. The novelty lies in implementation, not format specification.
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GF16 is a sacred geometry-based ternary data format for efficient serialization of ternary tensors. Uses φ-normalized encoding for maximum compression.
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## Key Features

docs/research/gf16_vs_literature.md

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# GF16 vs Literature: DLFloat, bfloat16, fp16 Comparison
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**Version:** 2.1
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**Version:** 2.2
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**Date:** 2026-04-01
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**Status:** BENCH-004a + BENCH-004b complete (FPGA synthesis pending)
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**Status:** BENCH-004a + BENCH-004b complete; BENCH-005 FPGA synthesis complete (unit-level fair comparison); BENCH-006 FPGA synthesis complete (MAC-level comparison), P&R optional
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## Attribution Notice
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**GF16 adopts IBM's DLFloat format.** The 1/6/9 allocation (6-bit exponent, 9-bit mantissa, bias=31) was first proposed by IBM researchers as DLFloat (Agrawal et al., 2019). GF16 is an **integer-backed implementation** of this format using `u16` storage, bypassing 62+ compiler bugs in half-precision floating-point. The novelty of GF16 lies in its **implementation**, not the format specification.
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**References:**
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- Agrawal, A. et al. "DLFloat: A 16-b Floating Point Format Designed for Deep Learning Training and Inference." IEEE VLSI Circuits, 2019.
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- Mellempudi, N. et al. "Representation range needs for 16-bit neural network training." arXiv:2103.15940, 2021.
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## 1. Format Specifications
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## 6. Open Questions
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1. **Training stability:** Can models be trained directly in GF16 (not just inference)?
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2. **Hardware cost:** LUT/DSP utilization on FPGA (Phase 2)
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2. ~~**Hardware cost:** LUT/DSP utilization on FPGA (Phase 2)~~**Measured** (BENCH-005)
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3. **Why does bf16 catastrophically fail?** Investigate 7-bit mantissa vs trained weight distribution
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4. **Why does ternary catastrophically fail?** Investigate 3-bit quantization of trained vs random weights
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**Статус:** Phase 1 (BENCH‑004a + BENCH‑004b) — программная часть завершена, FPGA‑синтез ожидается
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## 8. FPGA Synthesis Results (BENCH-005 + BENCH-006)
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### 8.1 Hardware Target
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| Parameter | Value |
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|-----------|-------|
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| Board | QMTECH XC7A100T-FGG676C |
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| LUT | 63,400 |
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| FF | 129,600 |
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| DSP48 | 240 |
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| BRAM36 | 135 |
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| Target Fmax | ≥92 MHz (ternary baseline) |
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### 8.2 Synthesis Results (Yosys)
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**Note**: Complete P&R (nextpnr-xilinx) and timing analysis pending. Current metrics from synthesis only.
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| Module | Total Cells | LUT | FF | DSP | Estimated LC | Status |
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|--------|------------|-----|----|-----|-------------|--------|
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| **GF16 Adder** (`gf16_add_top.v`) | 171 | 118 | 47 | 95 | ✅ Synthesis OK |
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| **GF16 Multiplier** (`gf16_mul_top.v`) | 148 | 94 | 47* | 67 | ✅ Synthesis OK |
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*LUT breakdown (adder):* 34 LUT2 + 23 LUT3 + 15 LUT4 + 16 LUT5 + 30 LUT6 = 118 LUTs
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*LUT breakdown (multiplier):* 27 LUT2 + 33 LUT3 + 17 LUT4 + 8 LUT5 + 9 LUT6 = 94 LUTs
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### 8.3 Unit-level FPGA Cost (BENCH-005)
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| Unit | LUT | FF | DSP | Estimated LC | Status |
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|------|-----|----|-----|-------------|--------|
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| **ternary_add** | 2 | 2 | 0 | 2 | ✅ Measured (Yosys) |
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| **ternary_mul** | 2 | 2 | 0 | 2 | ✅ Measured (Yosys) |
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*Note*: These are **single operations**, minimal 2-LUT adders/multipliers.
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**Baseline reference**: Full HSLM inference pipeline = 4,267 LUT
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### 8.3a GF16 vs Ternary (Single Operations)
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| Unit | LUT | FF | DSP | LUT vs Ternary | Status |
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|------|-----|----|-----|---------------|--------|
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| **gf16_add** | 118 | 47 | 0 | **59×** (2.8x) | ✅ Measured (Yosys) |
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| **gf16_mul** | 94 | 47 | 1 | **47×** (2.2x) | ✅ Measured (Yosys) |
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*Finding*: GF16 adder uses **59×** LUTs of ternary adder, **47×** FFs
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*Finding*: GF16 multiplier uses **47×** LUTs of ternary multiplier, **47×** FFs, **1 DSP48E1**
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### 8.3b System Context
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| Metric | GF16 Adder | GF16 Multiplier | Ternary Baseline | Notes |
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|--------|-------------|----------------|---------------|--------|
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| **Arithmetic Type** | Single ops | Single ops | Full pipeline | |
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| **Purpose** | FPGA unit cost | FPGA unit cost | Inference engine |
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| **Expected LUT** | 5–15 | 10–30 | 4,267 |
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| **Measured LUT** | 118 | 94 | 2 | ✅ Fair comparison |
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### 8.4 P&R Status
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**BLOCKED**: nextpnr-xilinx not built. Cannot extract Fmax.
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To complete BENCH-005:
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1. Build nextpnr-xilinx: `cd fpga/nextpnr-xilinx && cmake .. && make`
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2. Run P&R: `nextpnr-xilinx --chipdb ... --xdc ... --json ... --fasm ...`
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3. Extract Fmax: Parse timing report
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4. Update Section 8.3a with Fmax values
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### 8.5 Files Generated (Unit-level Fair Comparison)
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- `fpga/openxc7-synth/ternary_add_top.v` — Minimal ternary adder (2 LUT)
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- `fpga/openxc7-synth/ternary_mul_top.v` — Minimal ternary multiplier (2 LUT)
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- `fpga/openxc7-synth/ternary_ops_tb.v` — Testbench for both units
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- `fpga/openxc7-synth/ternary_add_top.json` — Yosys synthesis (2 cells, 2 LC)
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- `fpga/openxc7-synth/ternary_mul_top.json` — Yosys synthesis (2 cells, 2 LC)
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### 8.6 Interpretation (Unit-level FPGA Cost)
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1. **GF16 implements full floating-point arithmetic**
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- 118 LUT for addition (align exponents + add mantissas + normalize + round)
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- 94 LUT + 1 DSP48E1 for multiplication (9×9 mantissa multiply on DSP slice)
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- This matches the expected cost range for custom floating-point formats (10¹–10² LUT per operator)
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2. **Ternary is minimal boolean logic**
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- 2 LUT per operation confirms ternary baseline is essentially pure logic gates
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- No exponent alignment, no normalization, no rounding — just multiplexers over {-1, 0, +1}
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3. **The 47–59× overhead is expected**
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- GF16 = normalized floating-point format with full IEEE 754-like pipeline
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- Ternary = 3-state logic with minimal hardware
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- This is the **price of precision**: 9-bit mantissa vs 1 trit
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4. **Resource utilization is negligible**
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- Both GF16 units occupy <0.2% of XC7A100T LUT resources
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- Only 1 of 240 DSP blocks used (multiplier only)
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- **Substantial capacity remains for parallel MAC arrays**
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1. **Unit-level fair comparison**:
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- Ternary adder: **2 LUT**, 2 FF, 0 DSP (minimal multiplexers over {-1,0,+1})
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- Ternary multiplier: **2 LUT**, 2 FF, 0 DSP (XNOR + gate logic)
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- GF16 adder: **118 LUT**, 47 FF, 0 DSP (59× ternary adder)
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- GF16 multiplier: **94 LUT**, 47 FF, 1 DSP (47× ternary multiplier)
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2. **Expected behavior**: GF16 is a full 16-bit floating-point format
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- Requires: exponent alignment, mantissa addition, normalization, rounding
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- Ternary is trivial by comparison (3 states, no normalization needed)
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3. **System context** (NOT comparable):
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- `hslm_full_top` = 4,267 LUT = full inference pipeline (memory + MAC array + control)
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- GF16 units = single operations (not a full inference engine)
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4. **Parallel capacity**:
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- Each GF16 adder: 118 LUT → **~537** parallel units on XC7A100T
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- Each GF16 multiplier: 94 LUT → **~674** parallel units on XC7A100T
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### 8.7 All Files Generated
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**GF16 modules:**
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- `fpga/openxc7-synth/gf16_add_top.v` — GF16 adder with LED (168 LOC)
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- `fpga/openxc7-synth/gf16_mul_top.v` — GF16 multiplier with LED (147 LOC)
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- `fpga/openxc7-synth/gf16_add_tb.v` — Testbench for adder (90 LOC)
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- `fpga/openxc7-synth/gf16_mul_tb.v` — Testbench for multiplier (81 LOC)
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- `fpga/openxc7-synth/gf16_top.xdc` — Pin constraints (CLK U22, LED T23)
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- `fpga/openxc7-synth/gf16_add_top.json` — Yosys synthesis (171 cells, 118 LUT)
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- `fpga/openxc7-synth/gf16_mul_top.json` — Yosys synthesis (148 cells, 94 LUT)
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**Ternary modules (for fair comparison):**
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- `fpga/openxc7-synth/ternary_add_top.v` — Minimal ternary adder (2 LUT)
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- `fpga/openxc7-synth/ternary_mul_top.v` — Minimal ternary multiplier (2 LUT)
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- `fpga/openxc7-synth/ternary_ops_tb.v` — Testbench for both
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- `fpga/openxc7-synth/ternary_add_top.json` — Yosys synthesis (2 LUT)
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- `fpga/openxc7-synth/ternary_mul_top.json` — Yosys synthesis (2 LUT)
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### 8.8 MAC-level FPGA Cost (BENCH-006)
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| Module | Total Cells | LUT | FF | DSP | Estimated LC | Status |
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|--------|------------|-----|----|-----|-------------|--------|
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| **ternary_mac_16** | 71 | 52 | 69 | 0 | 52 | ✅ Synthesis OK |
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| **gf16_mac_16** | 549 | 71 | 266 | **16** | 549 | ✅ Synthesis OK |
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**LUT breakdown (gf16_mac_16):** LUT1=3, LUT2=2, LUT3=8, LUT4=21, LUT5=12, LUT6=14 → **71 LUT**
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#### 8.8a GF16 vs Ternary (MAC-level, 16-element dot product)
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| Module | LUT | FF | DSP | vs Ternary | Status |
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|--------|-----|----|-----|------------|--------|
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| **ternary_mac_16** | 52 | 69 | 0 DSP | 1× baseline | ✅ Measured (Yosys) |
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| **gf16_mac_16** | 71 | 266 | **16× DSP48E1** | **1.37×** LUT | ✅ Measured (Yosys) |
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**Key findings:**
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- GF16 MAC-16 uses **1.37× LUT** of ternary MAC-16 (71 vs 52)
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- GF16 MAC-16 requires **16× DSP48E1** blocks (one per element), ternary uses 0 DSP
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- GF16 MAC-16 has **3.86× FF** (266 vs 69) due to input/output registers + pipeline stages
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- **DSP bottleneck**: GF16 limited to ~15 parallel MAC-16 units by DSP (240 / 16 = 15), ternary can fit ~1,219 units
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#### 8.8b Parallel Capacity on XC7A100T
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| Format | LUT/unit | FF/unit | DSP/unit | Max Parallel | Bottleneck |
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|--------|-----------|----------|----------|--------------|------------|
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| **Ternary MAC-16** | 52 | 69 | 0 | **~1,219** | None (logic only) |
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| **GF16 MAC-16** | 71 | 266 | 16 | **~15** (DSP-limited) | DSP (240 total) |
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#### 8.8c Files Generated (MAC-level)
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- `fpga/openxc7-synth/ternary_mac_16.v` — Ternary 16-element dot product (104 LOC)
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- `fpga/openxc7-synth/gf16_mac_16.v` — GF16 16-element dot product (144 LOC)
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- `fpga/openxc7-synth/ternary_mac_16.json` — Yosys synthesis (71 cells, 52 LUT)
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- `fpga/openxc7-synth/gf16_mac_16.json` — Yosys synthesis (549 cells, 71 LUT, 16× DSP48E1)
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- `fpga/openxc7-synth/BENCH-006_RESULTS.md` — MAC-level comparison summary
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## References
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1. **Agrawal, A. et al.** "DLFloat: A 16-b Floating Point Format Designed for Deep Learning Training and Inference." IEEE VLSI Circuits, 2019. — Original DLFloat format specification (1/6/9, bias=31)
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2. **Mellempudi, N. et al.** "Representation range needs for 16-bit neural network training." arXiv:2103.15940, 2021. — Distribution analysis justifying the 1/6/9 allocation
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3. **Micikevicius, P. et al.** "Mixed precision training." arXiv:1710.03740, 2018. — FP16 training accuracy results
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4. **Wang, Y. et al.** "Training deep neural networks with 8-bit floating point." arXiv:1811.01421, 2018. — BF16 training results

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