feat: add embeddings, lstm, gelu

crates/core/src/cpu/activation.rs

@@ -7,6 +7,9 @@ pub struct CPUActivation {
 
 type ActivationFn = fn(x: &f32) -> f32;
 
+const ROOT_2_BY_PI: f32 = 0.7978845608028654;
+const GELU_APPROX: f32 = 0.044715;
+
 impl CPUActivation {
     pub fn from(activation: Activation) -> Self {
         let (activate, prime): (ActivationFn, ActivationFn) = match activation {
@@ -15,6 +18,7 @@ impl CPUActivation {
             Activation::Linear => (linear, linear_prime),
             Activation::Relu => (relu, relu_prime),
             Activation::Relu6 => (relu6, relu6_prime),
+            Activation::Gelu => (gelu, gelu_prime),
             Activation::Selu => (selu, selu_prime),
             Activation::Sigmoid => (sigmoid, sigmoid_prime),
             Activation::Tanh => (tanh, tanh_prime),
@@ -75,6 +79,16 @@ fn relu_prime(x: &f32) -> f32 {
     return if *x > 0.0 { 1.0 } else { 0.0 };
 }
 
+fn gelu(x: &f32) -> f32 {
+    return (0.5 * x) * (1.0 + (ROOT_2_BY_PI * (x + GELU_APPROX * x.powi(3))).tanh());
+}
+
+fn gelu_prime(x: &f32) -> f32 {
+    let tanned = (ROOT_2_BY_PI * (x + GELU_APPROX * x.powi(3))).tanh();
+    return (0.5 * (1.0 + tanned))
+        + (0.5 * x * (1.0 - tanned.powi(2))) * ROOT_2_BY_PI * (1.0 + 3.0 * GELU_APPROX * x.powi(2));
+}
+
 fn relu6(x: &f32) -> f32 {
     return x.max(0.0).min(6.0);
 }

crates/core/src/cpu/backend.rs

@@ -11,6 +11,8 @@ use crate::{
     Pool2DCPULayer, PostProcessor, SoftmaxCPULayer, Tensor, Tensors, Timer,
 };
 
+use super::{EmbeddingCPULayer, LSTMCPULayer};
+
 pub struct Backend {
     pub silent: bool,
     pub config: BackendConfig,
@@ -71,18 +73,28 @@ impl Backend {
                     size = layer.output_size().to_vec();
                     layers.push(CPULayer::Dense(layer));
                 }
-                Layer::Flatten(config) => {
-                    let layer = FlattenCPULayer::new(config, IxDyn(&size));
+                Layer::Embedding(config) => {
+                    let layer = EmbeddingCPULayer::new(config, IxDyn(&size));
+                    size = layer.output_size().to_vec();
+                    layers.push(CPULayer::Embedding(layer));
+                }
+                Layer::Flatten => {
+                    let layer = FlattenCPULayer::new(IxDyn(&size));
                     size = layer.output_size().to_vec();
                     layers.push(CPULayer::Flatten(layer));
                 }
+                Layer::LSTM(config) => {
+                    let layer = LSTMCPULayer::new(config, IxDyn(&size), None);
+                    size = layer.output_size().to_vec();
+                    layers.push(CPULayer::LSTM(layer));
+                }
                 Layer::Pool2D(config) => {
                     let layer = Pool2DCPULayer::new(config, IxDyn(&size));
                     size = layer.output_size().to_vec();
                     layers.push(CPULayer::Pool2D(layer));
                 }
-                Layer::Softmax => {
-                    let layer = SoftmaxCPULayer::new(IxDyn(&size));
+                Layer::Softmax(config) => {
+                    let layer = SoftmaxCPULayer::new(config, IxDyn(&size));
                     layers.push(CPULayer::Softmax(layer));
                 }
             }
@@ -125,7 +137,10 @@ impl Backend {
                 }
             }
             None => {
+      //          let mut i = 0;
                 for layer in &mut self.layers {
+       //             i += 1;
+       //             println!("\n\nLayer +{}: {:?}", i, &inputs);
                     inputs = layer.forward_propagate(inputs, training);
                 }
             }
@@ -138,9 +153,14 @@ impl Backend {
         outputs: ArrayViewD<'b, f32>,
         data: ArrayViewD<'b, f32>,
     ) -> ArrayD<f32> {
+ //       println!("\n\nOutput: {:?}", &outputs);
         let mut d_outputs = (self.cost.prime)(outputs, data);
+   //     println!("\n\nD Output: {:?}", &d_outputs);
+   //     let mut i = 0;
         for layer in self.layers.iter_mut().rev() {
+  //          i += 1;
             d_outputs = layer.backward_propagate(d_outputs);
+  //          println!("\n\nLayer -{}: {:?}", i, &d_outputs);
         }
         d_outputs
     }

crates/core/src/cpu/layer_norm.rs

@@ -0,0 +1,45 @@
+extern crate ndarray;
+use ndarray::{Array1, ArrayD, Axis};
+
+pub struct LayerNorm {
+    pub gamma: Array1<f32>,
+    pub beta: Array1<f32>,
+    pub epsilon: f32,
+}
+
+impl LayerNorm {
+    pub fn new(hidden_size: usize, epsilon: f32) -> Self {
+        LayerNorm {
+            gamma: Array1::ones(hidden_size),
+            beta: Array1::zeros(hidden_size),
+            epsilon,
+        }
+    }
+
+    pub fn forward(&self, input: ArrayD<f32>) -> ArrayD<f32> {
+        let shape = input.shape();
+        let last_axis = shape.len() - 1;
+
+        let mean = input.mean_axis(Axis(last_axis)).unwrap();
+        let variance = input.var_axis(Axis(last_axis), 0.0);
+
+        let mut normalized_input = input.clone();
+        normalized_input
+            .axis_iter_mut(Axis(last_axis))
+            .enumerate()
+            .for_each(|(i, mut row)| {
+                let mean_i = mean[i];
+                let var_i = variance[i].sqrt() + self.epsilon;
+                row -= mean_i;
+                row /= var_i;
+            });
+
+        normalized_input
+            .axis_iter_mut(Axis(last_axis))
+            .for_each(|mut item| {
+                let new = &item * &self.gamma + &self.beta;
+                item.assign(&new);
+            });
+        normalized_input
+    }
+}

crates/core/src/cpu/layers/activation.rs

@@ -1,7 +1,7 @@
 use ndarray::{s, ArrayD, Dimension, IxDyn};
-use std::ops::{Div, Mul, Sub};
+use std::{f32::EPSILON, ops::{Div, Mul, Sub}};
 
-use crate::{ActivationLayer, CPUActivation};
+use crate::{ActivationLayer, CPUActivation, SoftmaxLayer};
 
 pub struct ActivationCPULayer {
     pub outputs: ArrayD<f32>,
@@ -45,11 +45,13 @@ impl ActivationCPULayer {
 
 pub struct SoftmaxCPULayer {
     pub outputs: ArrayD<f32>,
+    pub temperature: f32,
 }
 
 impl SoftmaxCPULayer {
-    pub fn new(size: IxDyn) -> Self {
+    pub fn new(config: SoftmaxLayer, size: IxDyn) -> Self {
         Self {
+            temperature: config.temperature.unwrap_or(1f32),
             outputs: ArrayD::zeros(size),
         }
     }
@@ -68,18 +70,19 @@ impl SoftmaxCPULayer {
         self.outputs = inputs.clone();
         let batches = self.outputs.dim()[0];
         for b in 0..batches {
-            let exp = inputs.slice(s![b, ..]).map(|x| x.exp());
+            let current_input = inputs.slice(s![b, ..]).map(|x| x / self.temperature);
+            let max = current_input.iter().cloned().fold(f32::NEG_INFINITY, f32::max);
+            let exp = current_input.map(|x| (x - max).exp());
             self.outputs
                 .slice_mut(s![b, ..])
-                .assign(&exp.clone().div(exp.sum()));
+                .assign(&exp.clone().div(exp.sum() + EPSILON));
         }
         self.outputs.clone().into_dyn()
     }
 
     pub fn backward_propagate(&mut self, d_outputs: ArrayD<f32>) -> ArrayD<f32> {
         let batches = self.outputs.dim()[0];
         let array_size = self.outputs.dim().size() / batches;
-
         let mut d_inputs = ArrayD::zeros(self.outputs.dim());
         for b in 0..batches {
             for y in 0..array_size {

crates/core/src/cpu/layers/dropout.rs

@@ -30,7 +30,7 @@ impl Dropout1DCPULayer {
 
     pub fn forward_propagate(&mut self, inputs: ArrayD<f32>, training: bool) -> ArrayD<f32> {
         if training {
-            self.mask = ArrayD::random(self.mask.dim(), Uniform::new(0.0, 1.0))
+            self.mask = ArrayD::random(inputs.dim(), Uniform::new(0.0, 1.0))
                 .map(|x| (if x > &self.probability { 1.0 } else { 0.0 }));
             inputs.mul(&self.mask).mul(1.0 / 1.0 - self.probability)
         } else {

crates/core/src/cpu/layers/embedding.rs

@@ -0,0 +1,68 @@
+use std::ops::AddAssign;
+use ndarray::{Array2, ArrayD, Axis, Ix2, IxDyn};
+
+use crate::{CPUInit, CPURegularizer, EmbeddingLayer, Init};
+
+pub struct EmbeddingCPULayer {
+    pub input_size: IxDyn,
+    pub input_indices: Vec<usize>,
+    pub output_size: Vec<usize>,
+    pub vocab_size: usize,
+    pub embedding_size: usize,
+    pub embeddings: Array2<f32>,
+    pub d_embeddings: Array2<f32>,
+    // regularization
+    pub l_embeddings: Array2<f32>,
+
+    pub regularizer: CPURegularizer,
+}
+
+impl EmbeddingCPULayer {
+    pub fn new(config: EmbeddingLayer, size: IxDyn) -> Self {
+        let init = CPUInit::from(Init::Uniform);
+        let output_size = vec![size[0], size[1], config.embedding_size];
+        let embeddings = init.init(IxDyn(&[config.vocab_size, config.embedding_size]), 0, 0).into_dimensionality::<Ix2>().unwrap();
+        let d_embeddings = Array2::zeros((config.vocab_size, config.embedding_size));
+        Self {
+            input_size: size,
+            input_indices: vec![],
+            output_size,
+            vocab_size: config.vocab_size,
+            embedding_size: config.embedding_size,
+            embeddings,
+            d_embeddings,
+            l_embeddings: Array2::zeros((config.vocab_size, config.embedding_size)),
+            regularizer: CPURegularizer::from(config.c.unwrap_or(0.0), config.l1_ratio.unwrap_or(1.0))
+        }
+    }
+
+    pub fn output_size(&self) -> Vec<usize> {
+        self.output_size.clone()
+    }
+
+    pub fn reset(&mut self, batches: usize) {
+        self.output_size[0] = batches
+    }
+
+    pub fn forward_propagate(&mut self, inputs: ArrayD<f32>) -> ArrayD<f32> {
+        let input_indices: Vec<usize> = inputs.iter().map(|&x| x as usize).collect();
+        self.input_indices = input_indices.clone();
+        let embeddings = self.embeddings.select(Axis(0), input_indices.as_slice());
+//        let output_size = IxDyn(&self.output_size);
+        embeddings.into_shape_with_order(IxDyn(&[inputs.shape()[0], inputs.shape()[1], self.embedding_size])).unwrap()
+    }
+
+    pub fn backward_propagate(&mut self, d_outputs: ArrayD<f32>) -> ArrayD<f32> {
+        let indices = Array2::from_shape_vec(Ix2(d_outputs.shape()[0], self.input_size[1]), self.input_indices.clone());
+        self.d_embeddings = Array2::zeros((self.d_embeddings.shape()[0], self.d_embeddings.shape()[1]));
+        d_outputs.axis_iter(Axis(0)).zip(indices).for_each(|(rec, i)| {
+            rec.axis_iter(Axis(0)).zip(i).for_each(|(grad, idx)| {
+                self.d_embeddings.index_axis_mut(Axis(0), idx).add_assign(&grad);
+            });
+        });
+        self.l_embeddings = self.regularizer.coeff(&self.embeddings.clone().into_dyn()).into_dimensionality::<Ix2>().unwrap();
+        let mut input_size = self.input_size.clone();
+        input_size[0] = d_outputs.shape()[0];
+        ArrayD::from_shape_vec(input_size,  self.input_indices.iter().map(|x| *x as f32).collect()).unwrap()
+    }
+}

crates/core/src/cpu/layers/flatten.rs

@@ -1,26 +1,15 @@
 use ndarray::{ArrayD, Dimension, IxDyn};
 
-use crate::FlattenLayer;
-
 pub struct FlattenCPULayer {
     pub input_size: IxDyn,
     pub output_size: Vec<usize>,
 }
 
 impl FlattenCPULayer {
-    pub fn new(config: FlattenLayer, size: IxDyn) -> Self {
-        let mut new_size = config.size.clone();
-        new_size.insert(0, size[0]);
-        let output_size = IxDyn(&new_size);
-        if output_size.size() != size.size() {
-            panic!(
-                "Shape {:#?} is incompatible with shape {:#?}",
-                output_size, size
-            )
-        }
+    pub fn new(size: IxDyn) -> Self {
         Self {
-            input_size: size,
-            output_size: new_size,
+            input_size: size.clone(),
+            output_size: vec![size[0], size.size() / size[0]],
         }
     }
 
@@ -33,11 +22,14 @@ impl FlattenCPULayer {
     }
 
     pub fn forward_propagate(&mut self, inputs: ArrayD<f32>) -> ArrayD<f32> {
-        let output_size = IxDyn(&self.output_size);
+        let output_size = IxDyn(&[inputs.shape()[0], self.output_size[1]]);
+        println!("O {:?} {:?}", inputs.shape(), self.output_size);
         inputs.into_shape_with_order(output_size).unwrap()
     }
 
     pub fn backward_propagate(&mut self, d_outputs: ArrayD<f32>) -> ArrayD<f32> {
-        d_outputs.into_shape_with_order(self.input_size.clone()).unwrap()
+        let mut current_size = self.input_size.clone();
+        current_size[0] = d_outputs.shape()[0];
+        d_outputs.to_shape(current_size).unwrap().to_owned()
     }
 }