The Solidity port and EVM-specific work belongs to trifle-labs contributors,
not the original author. The MIT license still references Project Nayuki for
the derived algorithmic portions, satisfying the MIT requirement to retain the
original copyright notice in derivatives.
Updated in: QRCode.sol, QRCodeDemo.sol, Readme.markdown
Co-authored-by: okwme <964052+okwme@users.noreply.github.com>
Replace the pre-optimisation gas estimates with freshly measured values
after the GF256-table / uint256-grid / Yul-assembly rewrite:
Fixed mask: v1 byte ~930 k (was ~2.24 M), v5 ~3.3–3.6 M (was ~8.9 M)
Auto mask: v1 ~5.3 M, v3 ~11 M, v5 ~15.7 M (all now below 30 M limit)
SVG render: ~2.36 M for version-1 with 4-module border
Also adds a MASK_AUTO table, SVG row, and corrected scaling guide.
Co-authored-by: okwme <964052+okwme@users.noreply.github.com>
1. Pre-computed lookup tables as bytes constant
- GF256_EXP / GF256_LOG (256 bytes each) stored in bytecode;
replaces 8-iteration Russian-peasant GF(256) multiply with
3 table lookups in _gf256Mul.
- ALPHA_MAP (59 bytes) replaces 11-branch if-else chain in
_alphanumericCharIndex with 2 range checks + 1 lookup.
- _ECPB_* / _NECB_* ECC tables (4 x 41 bytes each) stored as
library constants; eliminates heap allocation per call.
2. uint256 row packing for the internal module grid
- Grid kept as uint256[] rows (bit x of rows[y] = module(x,y))
throughout _buildQrCode; converted to packed bytes only by
_gridToBytes at the end.
- _fillRect: 1 OR per row instead of width*height bit sets.
- _applyMask: per-row 256-bit XOR computed analytically from
9 precomputed 256-bit constants (_MASK0_EVEN/ODD, _MP0-2,
_MPA/B/6/C/D) — O(1) per row for all 8 masks.
- _drawCodewords: no y*size multiplication per module access.
3. Yul inline assembly for hot paths
- _reedSolomonComputeRemainder: full inner loop in assembly with
GF(256) multiply inlined via memory-resident log/exp tables;
eliminates bounds checks and function-call overhead.
- _getPenaltyScore N2/N4: vectorised 256-bit row operations +
inline popcnt64/popcnt256 reduce O(n^2) module reads to O(n)
word operations.
All 22 tests pass with byte-exact output matching the C reference.
Co-authored-by: okwme <964052+okwme@users.noreply.github.com>
- Added a readme file for each programming language implementation (port) if it didn't already have one, mostly by copying the project readme text, and then added/edited a couple of feature points.
billy rennekamp
copilot-swe-agent[bot]
Project Nayuki
Corvus