Add compute_layer_statistics() function

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Ed Addario 2025-08-03 16:35:03 +01:00
parent be60469f25
commit a6155a8125
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1 changed files with 60 additions and 4 deletions

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@ -272,11 +272,11 @@ static void compute_tensor_statistics(std::vector<tensor_statistics> & tstats) {
if (curr_avg.size() == prev_avg.size() && !curr_avg.empty()) {
float dot_prod = 0.0f, vec1 = 0.0f, vec2 = 0.0f;
for (size_t i = 0; i < curr_avg.size(); ++i) {
dot_prod += curr_avg[i]*prev_avg[i];
vec1 += curr_avg[i]*curr_avg[i];
vec2 += prev_avg[i]*prev_avg[i];
dot_prod += curr_avg[i] * prev_avg[i];
vec1 += curr_avg[i] * curr_avg[i];
vec2 += prev_avg[i] * prev_avg[i];
}
if (vec1 > 0 && vec2 > 0) ts.cossim = dot_prod / (std::sqrt(vec1)*std::sqrt(vec2));
if (vec1 > 0 && vec2 > 0) ts.cossim = dot_prod / (std::sqrt(vec1) * std::sqrt(vec2));
}
}
}
@ -308,6 +308,62 @@ static void compute_tensor_statistics(std::vector<tensor_statistics> & tstats) {
}
}
static void compute_layer_statistics(const std::vector<tensor_statistics> & tstats,
std::map<int, float> & layer_cossim,
const std::unordered_map<std::string, Stats> & stats_map) {
struct layer_aggregation {
std::vector<float> curr_avg;
std::vector<float> prev_avg;
};
static const std::regex pattern(R"(blk\.(\d+)\.)");
// index tensor stats by name for quick lookup
std::unordered_map<std::string, const tensor_statistics*> tidx;
tidx.reserve(tstats.size());
for (const auto & ts : tstats) tidx[ts.tensor] = &ts;
// concatenate per-layer
std::map<int, layer_aggregation> taggr; // ordered by layer
for (const auto & ts : tstats) {
std::smatch match;
if (!std::regex_search(ts.tensor, match, pattern)) continue;
const int blk = std::stoi(match[1]);
if (blk <= 0) continue;
std::string prev_lyr(ts.tensor);
prev_lyr.replace(match.position(1), match.length(1), std::to_string(blk-1));
if (auto it_prev = tidx.find(prev_lyr); it_prev == tidx.end()) continue;
// use stored Stats to rebuild averages
const auto curr_avg = compute_tensor_averages(stats_map.at(ts.tensor));
const auto prev_avg = compute_tensor_averages(stats_map.at(prev_lyr));
if (curr_avg.empty() || prev_avg.empty() || curr_avg.size() != prev_avg.size()) continue;
auto & [curr, prev] = taggr[blk];
curr.insert(curr.end(), curr_avg.begin(), curr_avg.end());
prev.insert(prev.end(), prev_avg.begin(), prev_avg.end());
}
// compute cosine per layer
for (auto & kv : taggr) {
const auto & curr = kv.second.curr_avg;
const auto & prev = kv.second.prev_avg;
if (curr.size() != prev.size() || curr.empty()) continue;
float dot_prod = 0.0, lyr1 = 0.0, lyr2 = 0.0;
for (size_t i = 0; i < curr.size(); ++i) {
const double a = curr[i], b = prev[i];
dot_prod += a*b;
lyr1 += a*a;
lyr2 += b*b;
}
float cossim = 0.0f;
if (lyr1 > 0.0 && lyr2 > 0.0) cossim = dot_prod / (std::sqrt(lyr1) * std::sqrt(lyr2));
layer_cossim[kv.first] = cossim;
}
}
bool IMatrixCollector::collect_imatrix(struct ggml_tensor * t, bool ask, void * user_data) {
GGML_UNUSED(user_data);