memlnaut-nisps/nisps/ml/storage.hpp
monkey-w1n5t0n f57cddc278 fix(ml): port RMSProp — ported learning rates were landing in SGD
Upstream memlp (github.com/MusicallyEmbodiedML/memlp @ ea777502, the commit
upstream/main pins) applies gradients with RMSProp everywhere: Layer.h:239
ApplyAccumulatedGradients, the m_sq_grad_avg running average at Layer.h:601,
StaticMLP.h:268. nisps/ml/training.hpp shipped SGD only and filed the
difference as an optimiser-choice research question. It was not one.

RMSProp divides each step by the running gradient magnitude, so an upstream
lr is a NORMALISED step; under SGD the same number multiplies the raw
gradient. Every learning rate ported from upstream therefore landed in an
optimiser that reads it differently — most visibly feedback.hpp's
`geo_lr_ = 0.001f  // upstream InterfaceRL.hpp:312`, an RMSProp LR pasted
into a single SGD step.

rmsprop_step() ports Layer.h:239 exactly: clip at +/-10, sq = min(0.9*sq +
0.1*g^2, 1e6), adj = min(lr/(sqrt(sq)+1e-6), 1.0), w -= adj*g. The
adjusted-LR clamp stays one-sided as upstream's std::min is, so the negative
lr used by train_targets' "train away from this target" path behaves as it
does upstream. The per-weight squared-gradient average is new persistent
state and lives in the storage policies (FixedStorage arrays /
DynamicStorage arena) so nisps/ stays allocation-free and the firmware's
zero-heap contract holds. It is optimiser state, not model state: excluded
from weight_count()/get_weights()/set_weights(), matching upstream, and
cleared by MLPCore::reset_optimizer_state() (upstream ResetOptimizerState).
draw_weights() deliberately does NOT clear it — upstream's DrawWeights
doesn't either.

Measured with tests/cpp/ml_bench.cpp:
  D1  one geometric dislike moves the mapping 1.6e-2, up from 5.3e-5 (~295x),
      and repeated presses now CONVERGE on the intended 0.5 push (0.12 at 10,
      0.56 at 100) instead of creeping linearly forever.
  A4  geometric-vs-Diffuse gap narrows from ~4100x to ~14x in one press.
  U4  the upstream-LR positive path actually trains now (range_util 0.71 at
      100 ticks/gesture, was 0.016 — it was inert under SGD).
Not fixed by this, and now tracked as ALIGNMENT defect 6d: the dose
asymmetry. lurch_max is still ~1.08 against a [0,1] output range.

Golden vector stages 2 and 3 re-captured; stages 0 and 1 are pre-training
and did not move, which is the cross-check that only the update rule
changed. manifold/public/nisps.wasm rebuilt so parity-check compares like
with like — it FAILED at up to 5e-2 against the stale artifact and PASSES at
2.4e-7 against a fresh one. parity-check.sh only builds the WASM when it is
missing, never when it is stale; noted in MAP.md and filed separately.

ALIGNMENT defect 6 resolved (moved to Recently resolved); 6b's optimiser
cross-reference updated; new defect 6d for the positive-training dose.

Gates: build-cpp-tests 138 tests / ctest 4/4, parity-check PASS, lint-cpp
clean, manifold typecheck clean.
2026-07-25 11:11:23 +02:00

253 lines
13 KiB
C++

// nisps/ml/storage.hpp — storage policies for the MLP core (fixed flavour).
//
// The MLP algorithms (nisps/ml/mlp.hpp `MLPCore<Storage>`) are written ONCE
// against a storage concept; the storage supplies every dimension and every
// buffer. Two models exist:
//
// * `FixedStorage<NIn, NH1, NH2, NH3, NOut, NMaxExamples, NMaxIterTrain>`
// (this file) — all buffers are template-sized `std::array`, zero heap.
// This is the firmware model; the classic
// `MLP<...>` template is an alias over it and its compile-time constants
// (`kInput`, `kHidden1..3`, `kOutput`, `weight_count()`) are preserved.
//
// * `DynamicStorage` (nisps/ml/dynamic_storage.hpp) — dimensions chosen at
// construction, one arena allocation, no allocation after construction.
// Compile-time EXCLUDED from embedded builds (see NISPS_TARGET_EMBEDDED
// in nisps/core/perf.hpp).
//
// STORAGE SURFACE (both models; L is the layer index 0..3)
// dims: n_in(), n_out(), fan_in_l<L>(), fan_out_l<L>(),
// max_examples(), max_iter_train(), weight_count()
// layers: weights_l<L>(), biases_l<L>(), pre_act_l<L>(), act_l<L>(),
// grad_w_l<L>(), grad_b_l<L>(),
// sq_grad_w_l<L>(), sq_grad_b_l<L>() [RMSProp running
// squared-gradient averages, same shape as the gradient
// accumulators — see nisps/ml/training.hpp],
// delta_l<L>() [backprop scratch,
// sized fan_in(L)], eval_act_l<L>() [const-eval scratch,
// sized fan_out(L), mutable]
// global: input_buf(), output_buf(), ds_features(), ds_labels(),
// flat_buf(), loss_hist_buf(), copy_weights_to(dst)
//
// For `FixedStorage` every dim accessor is constexpr-foldable, so the
// algorithms compile to the same fully-unrolled/constant-bound code the old
// hand-fixed MLP produced (verified against the RP2350 `.text` budget —
// chokepoint B of docs/specs/plans/one-core-engine-refactor.md).
//
// Bit-parity contract: for identical shapes and seeds, MLPCore over
// FixedStorage and DynamicStorage must produce bit-identical results — the
// algorithm code is shared and the buffers are just memory. A ctest enforces
// this (tests/cpp/test_mlp_storage_parity.cpp).
#pragma once
#include <array>
#include <cstddef>
#include <span>
#include "../core/perf.hpp"
namespace nisps::ml {
inline constexpr std::size_t kMlpNumLayers = 4u;
// Default example-store capacity, named ONCE and shared by FixedStorage's
// compile-time default (below) and DynamicStorage's runtime-default
// constructor argument (nisps/ml/dynamic_storage.hpp). `nisps_ml_describe`
// (nisps/wasm/bindings.cpp) reports the live instance's max_examples() so
// the Manifold TS side (manifold/src/engine/wasm-iml.ts) can size its JS
// Dataset mirror to match instead of hardcoding a second, divergent number
// (see docs/specs/recon/simplification-audit-2026-07.md S35).
inline constexpr std::size_t kDefaultMaxExamples = 128u;
template <std::size_t NIn,
std::size_t NHidden1,
std::size_t NHidden2,
std::size_t NHidden3,
std::size_t NOut,
std::size_t NMaxExamples = kDefaultMaxExamples,
std::size_t NMaxIterTrain = 4096u>
class FixedStorage {
public:
static constexpr std::size_t kInput = NIn;
static constexpr std::size_t kHidden1 = NHidden1;
static constexpr std::size_t kHidden2 = NHidden2;
static constexpr std::size_t kHidden3 = NHidden3;
static constexpr std::size_t kOutput = NOut;
static constexpr std::size_t kMaxExamples = NMaxExamples;
static constexpr std::size_t kMaxIterTrain = NMaxIterTrain;
static constexpr std::size_t kNumLayers = kMlpNumLayers;
static constexpr std::size_t weight_count() noexcept {
return NIn * NHidden1 + NHidden1 * NHidden2 + NHidden2 * NHidden3 + NHidden3 * NOut
+ NHidden1 + NHidden2 + NHidden3 + NOut;
}
// ---- dims -----------------------------------------------------------
static constexpr std::size_t n_in() noexcept { return NIn; }
static constexpr std::size_t n_out() noexcept { return NOut; }
static constexpr std::size_t max_examples() noexcept { return NMaxExamples; }
static constexpr std::size_t max_iter_train() noexcept { return NMaxIterTrain; }
template <std::size_t L>
static constexpr std::size_t fan_in_l() noexcept {
static_assert(L < kNumLayers);
if constexpr (L == 0u) return NIn;
else if constexpr (L == 1u) return NHidden1;
else if constexpr (L == 2u) return NHidden2;
else return NHidden3;
}
template <std::size_t L>
static constexpr std::size_t fan_out_l() noexcept {
static_assert(L < kNumLayers);
if constexpr (L == 0u) return NHidden1;
else if constexpr (L == 1u) return NHidden2;
else if constexpr (L == 2u) return NHidden3;
else return NOut;
}
// ---- per-layer buffers ------------------------------------------------
template <std::size_t L> NISPS_FORCE_INLINE std::span<float> weights_l() noexcept {
if constexpr (L == 0u) return w0_; else if constexpr (L == 1u) return w1_;
else if constexpr (L == 2u) return w2_; else return w3_;
}
template <std::size_t L> NISPS_FORCE_INLINE std::span<const float> weights_l() const noexcept {
if constexpr (L == 0u) return w0_; else if constexpr (L == 1u) return w1_;
else if constexpr (L == 2u) return w2_; else return w3_;
}
template <std::size_t L> NISPS_FORCE_INLINE std::span<float> biases_l() noexcept {
if constexpr (L == 0u) return b0_; else if constexpr (L == 1u) return b1_;
else if constexpr (L == 2u) return b2_; else return b3_;
}
template <std::size_t L> NISPS_FORCE_INLINE std::span<const float> biases_l() const noexcept {
if constexpr (L == 0u) return b0_; else if constexpr (L == 1u) return b1_;
else if constexpr (L == 2u) return b2_; else return b3_;
}
template <std::size_t L> NISPS_FORCE_INLINE std::span<float> pre_act_l() noexcept {
if constexpr (L == 0u) return pa0_; else if constexpr (L == 1u) return pa1_;
else if constexpr (L == 2u) return pa2_; else return pa3_;
}
template <std::size_t L> NISPS_FORCE_INLINE std::span<float> act_l() noexcept {
if constexpr (L == 0u) return a0_; else if constexpr (L == 1u) return a1_;
else if constexpr (L == 2u) return a2_; else return a3_;
}
template <std::size_t L> NISPS_FORCE_INLINE std::span<const float> act_l() const noexcept {
if constexpr (L == 0u) return a0_; else if constexpr (L == 1u) return a1_;
else if constexpr (L == 2u) return a2_; else return a3_;
}
template <std::size_t L> NISPS_FORCE_INLINE std::span<float> grad_w_l() noexcept {
if constexpr (L == 0u) return gw0_; else if constexpr (L == 1u) return gw1_;
else if constexpr (L == 2u) return gw2_; else return gw3_;
}
template <std::size_t L> NISPS_FORCE_INLINE std::span<float> grad_b_l() noexcept {
if constexpr (L == 0u) return gb0_; else if constexpr (L == 1u) return gb1_;
else if constexpr (L == 2u) return gb2_; else return gb3_;
}
// RMSProp running squared-gradient averages (training.hpp). Optimiser
// state, not model state: excluded from weight_count()/copy_weights_to().
template <std::size_t L> NISPS_FORCE_INLINE std::span<float> sq_grad_w_l() noexcept {
if constexpr (L == 0u) return sw0_; else if constexpr (L == 1u) return sw1_;
else if constexpr (L == 2u) return sw2_; else return sw3_;
}
template <std::size_t L> NISPS_FORCE_INLINE std::span<float> sq_grad_b_l() noexcept {
if constexpr (L == 0u) return sb0_; else if constexpr (L == 1u) return sb1_;
else if constexpr (L == 2u) return sb2_; else return sb3_;
}
// Backprop scratch (delta into layer L's input), sized fan_in(L).
template <std::size_t L> NISPS_FORCE_INLINE std::span<float> delta_l() noexcept {
if constexpr (L == 0u) return d0_; else if constexpr (L == 1u) return d1_;
else if constexpr (L == 2u) return d2_; else return d3_;
}
// Const-eval scratch (activation of layer L), sized fan_out(L). Mutable
// so `eval_loss() const` can run the shared forward code without touching
// the real activation caches.
template <std::size_t L> NISPS_FORCE_INLINE std::span<float> eval_act_l() const noexcept {
if constexpr (L == 0u) return e0_; else if constexpr (L == 1u) return e1_;
else if constexpr (L == 2u) return e2_; else return e3_;
}
// ---- global buffers ---------------------------------------------------
NISPS_FORCE_INLINE std::span<float> input_buf() noexcept { return input_; }
NISPS_FORCE_INLINE std::span<const float> input_buf() const noexcept { return input_; }
NISPS_FORCE_INLINE std::span<float> output_buf() noexcept { return output_; }
NISPS_FORCE_INLINE std::span<const float> output_buf() const noexcept { return output_; }
NISPS_FORCE_INLINE std::span<float> ds_features() noexcept { return dsf_; }
NISPS_FORCE_INLINE std::span<const float> ds_features() const noexcept { return dsf_; }
NISPS_FORCE_INLINE std::span<float> ds_labels() noexcept { return dsl_; }
NISPS_FORCE_INLINE std::span<const float> ds_labels() const noexcept { return dsl_; }
NISPS_FORCE_INLINE std::span<float> flat_buf() noexcept { return flat_; }
NISPS_FORCE_INLINE std::span<float> loss_hist_buf() noexcept { return lh_; }
NISPS_FORCE_INLINE std::span<const float> loss_hist_buf() const noexcept { return lh_; }
// Copies the live weights+biases directly into `dst` in the same flat
// layout as MLPCore::get_weights() (weights layer-major, then biases
// layer-major) — but writes straight from the layer buffers, with no
// intermediate flat_/flat_buf() hop. `dst` must be at least
// weight_count() long. Lets a caller that only needs a transient copy
// (feedback.hpp's snapshot/undo/nudge ops) take a single copy instead of
// double-copying through get_weights()'s scratch buffer.
void copy_weights_to(std::span<float> dst) const noexcept {
std::size_t k = 0u;
for (float v : weights_l<0u>()) dst[k++] = v;
for (float v : weights_l<1u>()) dst[k++] = v;
for (float v : weights_l<2u>()) dst[k++] = v;
for (float v : weights_l<3u>()) dst[k++] = v;
for (float v : biases_l<0u>()) dst[k++] = v;
for (float v : biases_l<1u>()) dst[k++] = v;
for (float v : biases_l<2u>()) dst[k++] = v;
for (float v : biases_l<3u>()) dst[k++] = v;
}
private:
std::array<float, NIn * NHidden1> w0_{};
std::array<float, NHidden1 * NHidden2> w1_{};
std::array<float, NHidden2 * NHidden3> w2_{};
std::array<float, NHidden3 * NOut> w3_{};
std::array<float, NHidden1> b0_{};
std::array<float, NHidden2> b1_{};
std::array<float, NHidden3> b2_{};
std::array<float, NOut> b3_{};
std::array<float, NHidden1> pa0_{};
std::array<float, NHidden2> pa1_{};
std::array<float, NHidden3> pa2_{};
std::array<float, NOut> pa3_{};
std::array<float, NHidden1> a0_{};
std::array<float, NHidden2> a1_{};
std::array<float, NHidden3> a2_{};
std::array<float, NOut> a3_{};
std::array<float, NIn * NHidden1> gw0_{};
std::array<float, NHidden1 * NHidden2> gw1_{};
std::array<float, NHidden2 * NHidden3> gw2_{};
std::array<float, NHidden3 * NOut> gw3_{};
std::array<float, NHidden1> gb0_{};
std::array<float, NHidden2> gb1_{};
std::array<float, NHidden3> gb2_{};
std::array<float, NOut> gb3_{};
std::array<float, NIn * NHidden1> sw0_{};
std::array<float, NHidden1 * NHidden2> sw1_{};
std::array<float, NHidden2 * NHidden3> sw2_{};
std::array<float, NHidden3 * NOut> sw3_{};
std::array<float, NHidden1> sb0_{};
std::array<float, NHidden2> sb1_{};
std::array<float, NHidden3> sb2_{};
std::array<float, NOut> sb3_{};
std::array<float, NIn> d0_{};
std::array<float, NHidden1> d1_{};
std::array<float, NHidden2> d2_{};
std::array<float, NHidden3> d3_{};
mutable std::array<float, NHidden1> e0_{};
mutable std::array<float, NHidden2> e1_{};
mutable std::array<float, NHidden3> e2_{};
mutable std::array<float, NOut> e3_{};
std::array<float, NIn> input_{};
std::array<float, NOut> output_{};
std::array<float, NMaxExamples * NIn> dsf_{};
std::array<float, NMaxExamples * NOut> dsl_{};
std::array<float, weight_count()> flat_{};
std::array<float, NMaxIterTrain> lh_{};
};
} // namespace nisps::ml