Performance-portable, length-agnostic SIMD with runtime dispatch
This report summarizes scanner evidence for google/highway, a C++ project with 5,950 GitHub stars. SynthScan examined 170,040 lines of code across 146 source files, recording 739 pattern matches distributed across 9 syntactic categories. The legacy adjusted pattern signal is 4.2 (Low pattern signal); it is not an authorship estimate.
Use the findings to ask whether maintainers can explain intent, verify dependencies, simplify unnecessary scaffolding, and focus review effort. Risk Payload v1 adds ownership, supply-chain, over-engineering, and review-effort vectors when available. These are prompts for human verification, not probabilities, security findings, or measured maintenance costs.
Use each vector to guide manual verification of the underlying findings.
Payload schema: 1.0.0 · Engine: 2.0.0 · Scoring: heuristic-density-v1 · Scan date: 2026-10-31.
Can maintainers explain intent, assumptions, and trade-offs? 737 finding(s).
Are imports declared and package/API names verified? 1 finding(s).
Are wrappers, guards, and repeated structures necessary? 2 finding(s).
Which changes need focused human review? 739 finding(s).
This chart tracks the legacy adjusted pattern score across scan runs. Changes can reflect source changes, scan coverage, or detector/scoring versions; they do not measure AI adoption or prove that a team refactored code. Compare runs only when their scoring versions are compatible. The dashed line tracks the raw pattern-hit count.
Groups findings by configured severity weight. Severity is not a confidence estimate, security rating, or proof that a package is missing. Verify imports against the project's manifests and inspect each finding in its local design context.
This horizontal bar chart shows where configured pattern scores accumulate across directories. Treat the bars as locations to inspect, not as evidence of authorship or code quality. Use the file-level findings to decide whether a directory needs a focused ownership, dependency, complexity, or review check.
The scanner identified 739 distinct pattern matches across 9 syntactic categories. Each entry below represents a discrete location in the source code where the engine recorded a detector match to inspect in context. Expand any category row to inspect the individual file paths, line numbers, code snippets, and the lexical context (CODE, COMMENT, or STRING) in which each match was detected.
Reading the findings table: The Severity column indicates the configured finding weight (CRITICAL / HIGH / MEDIUM / LOW). The Context column identifies whether the match occurred inside executable code, an inline comment, or a string literal — legacy comment-context matches receive a ×1.5 score weight. The ⚡ bolt icon marks clustered matches: three or more patterns within a 10-line window, each receiving an additional ×1.5 density multiplier under the legacy scoring model.
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | CMakeLists.txt | 1 | # Copyright 2019 Google LLC | COMMENT |
| LOW | hwy/highway.h | 1 | // Copyright 2020 Google LLC | COMMENT |
| LOW | hwy/highway.h | 21 | #include "hwy/detect_targets.h" | COMMENT |
| LOW | hwy/highway.h | 41 | // Shorthand for tags (defined in shared-inl.h) used to select overloads. | COMMENT |
| LOW | hwy/highway.h | 61 | //------------------------------------------------------------------------------ | COMMENT |
| LOW | hwy/highway.h | 81 | #define HWY_STATIC_NAMESPACE N_WASM | COMMENT |
| LOW | hwy/highway.h | 101 | #define HWY_STATIC_NAMESPACE N_NEON_WITHOUT_AES | COMMENT |
| LOW | hwy/highway.h | 121 | #define HWY_STATIC_NAMESPACE N_AVX2 | COMMENT |
| LOW | hwy/highway.h | 141 | // that target was not compiled. | COMMENT |
| LOW | hwy/highway.h | 161 | #define HWY_VISIT_WASM(VISITOR) | COMMENT |
| LOW | hwy/highway.h | 181 | #define HWY_CHOOSE_Z15(FUNC_NAME) &N_Z15::FUNC_NAME | COMMENT |
| LOW | hwy/highway.h | 201 | #define HWY_VISIT_PPC9(VISITOR) | COMMENT |
| LOW | hwy/highway.h | 221 | #define HWY_CHOOSE_PPC10(FUNC_NAME) &N_PPC10::FUNC_NAME | COMMENT |
| LOW | hwy/highway.h | 241 | #define HWY_CHOOSE_NEON_WITHOUT_AES(FUNC_NAME) nullptr | COMMENT |
| LOW | hwy/highway.h | 261 | #if HWY_TARGETS & HWY_SVE | COMMENT |
| LOW | hwy/highway.h | 281 | #define HWY_CHOOSE_SVE_256(FUNC_NAME) nullptr | COMMENT |
| LOW | hwy/highway.h | 301 | #if HWY_TARGETS & HWY_SSSE3 | COMMENT |
| LOW | hwy/highway.h | 321 | #define HWY_CHOOSE_AVX2(FUNC_NAME) nullptr | COMMENT |
| LOW | hwy/highway.h | 341 | #if HWY_TARGETS & HWY_AVX3_ZEN4 | COMMENT |
| LOW | hwy/highway.h | 361 | #define HWY_CHOOSE_AVX10_2(FUNC_NAME) nullptr | COMMENT |
| LOW | hwy/highway.h | 401 | const FuncPtr* table; | COMMENT |
| LOW | hwy/highway.h | 481 | HWY_CONCAT(FUNC_NAME, HighwayDispatchTable) | COMMENT |
| LOW | hwy/highway.h | 501 | // namespace skeleton { | COMMENT |
| LOW | hwy/highway.h | 521 | // | COMMENT |
| LOW | hwy/highway.h | 541 | HWY_DISPATCH_TABLE(TABLE_NAME)[1] = {&HWY_STATIC_DISPATCH(FUNC_NAME)} | COMMENT |
| LOW | hwy/highway.h | 561 | // 1) An extra function parameter would be unacceptable because it changes the | COMMENT |
| LOW | hwy/highway.h | 661 | COMMENT | |
| LOW | hwy/highway.h | 681 | COMMENT | |
| LOW | hwy/highway.h | 701 | COMMENT | |
| LOW | hwy/highway.h | 721 | #endif | COMMENT |
| LOW | hwy/highway.h | 741 | #elif HWY_TARGET == HWY_WASM_EMU256 | COMMENT |
| LOW | hwy/print-inl.h | 1 | // Copyright 2022 Google LLC | COMMENT |
| LOW | hwy/print-inl.h | 21 | #include "hwy/print.h" | COMMENT |
| LOW | hwy/highway_export.h | 1 | // Pseudo-generated file to handle both cmake & bazel build system. | COMMENT |
| LOW | hwy/highway_export.h | 21 | #ifdef _WIN32 | COMMENT |
| LOW | hwy/highway_export.h | 41 | #else | COMMENT |
| LOW | hwy/highway_export.h | 61 | #endif | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 1 | // Copyright 2020 Google LLC | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 21 | COMMENT | |
| LOW | hwy/detect_compiler_arch.h | 41 | #if defined(_MSC_VER) && !defined(__clang__) | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 61 | #else | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 81 | #if __has_builtin(__builtin_elementwise_fshl) | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 101 | #elif __has_warning("-Wreserved-identifier") | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 121 | #else // Anything older than 7.0 is not recommended for Highway. | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 141 | !HWY_COMPILER_ICX | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 161 | // Compiler features and C++ version | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 181 | #ifdef __has_feature | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 201 | #if defined(__cpp_constexpr) && __cpp_constexpr >= 201304L | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 221 | #define HWY_IF_CONSTEXPR if constexpr | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 241 | #if HWY_HAS_FEATURE(memory_sanitizer) || defined(MEMORY_SANITIZER) || \ | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 261 | COMMENT | |
| LOW | hwy/detect_compiler_arch.h | 281 | #define HWY_ATTR_NO_MSAN | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 301 | #else | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 321 | #endif | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 341 | #endif | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 361 | #if defined(__EMSCRIPTEN__) || defined(__wasm__) || defined(__WASM__) | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 381 | #endif | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 401 | #define HWY_ARCH_S390X 0 | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 421 | #endif | COMMENT |
| LOW | hwy/detect_compiler_arch.h | 441 | #elif HWY_ARCH_HEXAGON | COMMENT |
| 638 more matches not shown… | ||||
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | hwy/nanobenchmark.h | 20 | // prediction hit rates. Uses a robust estimator to summarize the measurements. | COMMENT |
| MEDIUM | hwy/nanobenchmark.h | 46 | // which is more robust to outliers and skewed data than the mean or median. | COMMENT |
| MEDIUM | hwy/auto_tune.h | 78 | // - The minimum is not a robust estimator because there are also "lucky | COMMENT |
| MEDIUM | hwy/auto_tune.h | 96 | // - Trim the initial sample via MAD or skewness for a robust estimate of the | COMMENT |
| MEDIUM | hwy/auto_tune.h | 153 | // deviation, which is robust to almost half of the sample being outliers. | COMMENT |
| MEDIUM | hwy/robust_statistics.h | 82 | // Half Sample Mode estimator proposed by Bickel in "On a fast, robust | COMMENT |
| MEDIUM | hwy/robust_statistics.h | 132 | // Returns a robust measure of variability. | COMMENT |
| MEDIUM | hwy/contrib/hash/phast-inl.h | 123 | // Two vectors have higher throughput because they utilize all 16-bit lanes | COMMENT |
| MEDIUM | hwy/contrib/btree/btree-inl.h | 179 | // to utilize all 64 bits of the mask register, reducing the number of | COMMENT |
| MEDIUM | hwy/ops/rvv-inl.h | 5355 | // Definitely at least 128 bit: match x86 semantics (independent blocks). Using | COMMENT |
| MEDIUM | hwy/ops/rvv-inl.h | 5415 | // Definitely less than 128-bit only if there is a small cap; fractional LMUL | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW⚡ | hwy/contrib/math/fast_math-inl.h | 46 | // Step 1: Find the nearest integer multiple of pi: | COMMENT |
| LOW⚡ | hwy/contrib/math/fast_math-inl.h | 50 | // Step 2: Cody-Waite multi-word range reduction: | COMMENT |
| LOW⚡ | hwy/contrib/math/fast_math-inl.h | 126 | // Step 3: Extract sign and magnitude x_red = |ang_mod| in [0, pi/2]. | COMMENT |
| LOW⚡ | hwy/contrib/math/fast_math-inl.h | 131 | // Step 4: Compute dx = (pi/2 - x_red) without losing low-order bits near the | COMMENT |
| LOW⚡ | hwy/contrib/math/fast_math-inl.h | 181 | // Step 1: GetMantissa0p75_1p5(x) directly extracts y in [0.75, 1.50) in one | COMMENT |
| LOW⚡ | hwy/contrib/math/fast_math-inl.h | 184 | // Step 2: GetExponent(x) returns the original exponent k, and | COMMENT |
| LOW⚡ | hwy/contrib/math/fast_math-inl.h | 364 | // Step 1: Reduce `x` modulo pi to: | COMMENT |
| LOW⚡ | hwy/contrib/math/fast_math-inl.h | 372 | // Step 2: Rational approximation with an exact pole at x = pi/2. | COMMENT |
| LOW | hwy/contrib/math/fast_math-inl.h | 209 | // Step 1: Compute shifted exponent e = k (if m < 1.5) or k + 1 (if m | COMMENT |
| LOW | hwy/contrib/math/fast_math-inl.h | 237 | // Step 2: Shift right by p bits and subtract bias to obtain integer e. | COMMENT |
| LOW | hwy/contrib/math/fast_math-inl.h | 250 | // Step 3: Compute y = x / 2^e in [0.75, 1.50). | COMMENT |
| LOW | hwy/contrib/math/fast_math-inl.h | 410 | // Step 3: Reconstruct signed tan(x) = num / den. | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW⚡ | hwy/contrib/math/fast_math-inl.h | 46 | // Step 1: Find the nearest integer multiple of pi: | COMMENT |
| LOW⚡ | hwy/contrib/math/fast_math-inl.h | 50 | // Step 2: Cody-Waite multi-word range reduction: | COMMENT |
| LOW⚡ | hwy/contrib/math/fast_math-inl.h | 126 | // Step 3: Extract sign and magnitude x_red = |ang_mod| in [0, pi/2]. | COMMENT |
| LOW⚡ | hwy/contrib/math/fast_math-inl.h | 131 | // Step 4: Compute dx = (pi/2 - x_red) without losing low-order bits near the | COMMENT |
| LOW⚡ | hwy/contrib/math/fast_math-inl.h | 181 | // Step 1: GetMantissa0p75_1p5(x) directly extracts y in [0.75, 1.50) in one | COMMENT |
| LOW⚡ | hwy/contrib/math/fast_math-inl.h | 184 | // Step 2: GetExponent(x) returns the original exponent k, and | COMMENT |
| LOW⚡ | hwy/contrib/math/fast_math-inl.h | 364 | // Step 1: Reduce `x` modulo pi to: | COMMENT |
| LOW⚡ | hwy/contrib/math/fast_math-inl.h | 372 | // Step 2: Rational approximation with an exact pole at x = pi/2. | COMMENT |
| LOW | hwy/contrib/math/fast_math-inl.h | 209 | // Step 1: Compute shifted exponent e = k (if m < 1.5) or k + 1 (if m | COMMENT |
| LOW | hwy/contrib/math/fast_math-inl.h | 237 | // Step 2: Shift right by p bits and subtract bias to obtain integer e. | COMMENT |
| LOW | hwy/contrib/math/fast_math-inl.h | 250 | // Step 3: Compute y = x / 2^e in [0.75, 1.50). | COMMENT |
| LOW | hwy/contrib/math/fast_math-inl.h | 410 | // Step 3: Reconstruct signed tan(x) = num / den. | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | CMakeLists.txt | 695 | # -------------------------------------------------------- | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | hwy/contrib/btree/btree-inl.h | 2274 | // Example usage: | COMMENT |
| LOW | hwy/contrib/btree/btree-inl.h | 2338 | // Example usage: | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | docs/conf.py | 14 | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | docs/mm-converter.py | 44 | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | docs/mm-converter.py | 78 | CODE |