mirror of
https://github.com/huggingface/candle.git
synced 2025-06-16 18:48:51 +00:00
Layer norm tweaks (#482)
* Add some options to make layer-norm more configurable. * Add the rms-norm variant. * Replace the RmsNorm with the shared bits.
This commit is contained in:
@ -152,35 +152,20 @@ fn embedding(cfg: &Config, vb: VarBuilder) -> Result<Embedding> {
|
||||
}
|
||||
|
||||
struct RmsNorm {
|
||||
scale: Tensor,
|
||||
eps: f64,
|
||||
inner: candle_nn::LayerNorm,
|
||||
span: tracing::Span,
|
||||
}
|
||||
|
||||
impl RmsNorm {
|
||||
fn load(size: usize, eps: f64, vb: VarBuilder) -> Result<Self> {
|
||||
let span = tracing::span!(tracing::Level::TRACE, "rms-norm");
|
||||
let scale = vb.get(size, "weight")?;
|
||||
Ok(Self { scale, eps, span })
|
||||
let inner = candle_nn::rms_norm(size, eps, vb)?;
|
||||
Ok(Self { inner, span })
|
||||
}
|
||||
|
||||
fn forward(&self, x: &Tensor) -> Result<Tensor> {
|
||||
let _enter = self.span.enter();
|
||||
let in_dtype = x.dtype();
|
||||
// This is a no-op if x's dtype is already f32.
|
||||
let x = x.to_dtype(DType::F32)?;
|
||||
let (b_sz, seq_len, hidden_size) = x.dims3()?;
|
||||
let norm_x = (x.sqr()?.sum_keepdim(2)? / hidden_size as f64)?;
|
||||
let norm_x = norm_x.broadcast_as((b_sz, seq_len, hidden_size))?;
|
||||
let x_normed = (x / (norm_x + self.eps)?.sqrt()?)?;
|
||||
let size = self.scale.dims1()?;
|
||||
let scale = self
|
||||
.scale
|
||||
.to_dtype(DType::F32)?
|
||||
.broadcast_as((b_sz, seq_len, size))?;
|
||||
let x = (scale * x_normed)?;
|
||||
let x = x.to_dtype(in_dtype)?;
|
||||
Ok(x)
|
||||
self.inner.forward(x)
|
||||
}
|
||||
}
|
||||
|
||||
|
@ -1,6 +1,6 @@
|
||||
use candle::{DType, Device, IndexOp, Result, Tensor, D};
|
||||
use candle_nn::linear_no_bias as linear;
|
||||
use candle_nn::{embedding, Embedding, Linear, VarBuilder};
|
||||
use candle_nn::{embedding, rms_norm, Embedding, LayerNorm, Linear, VarBuilder};
|
||||
use std::collections::HashMap;
|
||||
use std::sync::{Arc, Mutex};
|
||||
|
||||
@ -94,32 +94,6 @@ fn silu(xs: &Tensor) -> Result<Tensor> {
|
||||
xs / (xs.neg()?.exp()? + 1.0)?
|
||||
}
|
||||
|
||||
struct RmsNorm {
|
||||
scale: Tensor,
|
||||
eps: f64,
|
||||
}
|
||||
|
||||
impl RmsNorm {
|
||||
fn load(size: usize, eps: f64, vb: VarBuilder) -> Result<Self> {
|
||||
let scale = vb.get_or_init(size, "weight", candle_nn::Init::Const(1.))?;
|
||||
Ok(Self { scale, eps })
|
||||
}
|
||||
|
||||
fn forward(&self, x: &Tensor) -> Result<Tensor> {
|
||||
let (b_sz, seq_len, hidden_size) = x.dims3()?;
|
||||
let norm_x = (x.sqr()?.sum_keepdim(D::Minus1)? / hidden_size as f64)?;
|
||||
let norm_x = norm_x.broadcast_as((b_sz, seq_len, hidden_size))?;
|
||||
let x_normed = (x / (norm_x + self.eps)?.sqrt()?)?;
|
||||
let size = self.scale.dims1()?;
|
||||
let scale = self
|
||||
.scale
|
||||
.to_dtype(DType::F32)?
|
||||
.broadcast_as((b_sz, seq_len, size))?;
|
||||
let x = (scale * x_normed)?;
|
||||
Ok(x)
|
||||
}
|
||||
}
|
||||
|
||||
struct CausalSelfAttention {
|
||||
q_proj: Linear,
|
||||
k_proj: Linear,
|
||||
@ -262,14 +236,14 @@ impl Mlp {
|
||||
}
|
||||
|
||||
struct Block {
|
||||
rms_1: RmsNorm,
|
||||
rms_1: LayerNorm,
|
||||
attn: CausalSelfAttention,
|
||||
rms_2: RmsNorm,
|
||||
rms_2: LayerNorm,
|
||||
mlp: Mlp,
|
||||
}
|
||||
|
||||
impl Block {
|
||||
fn new(rms_1: RmsNorm, attn: CausalSelfAttention, rms_2: RmsNorm, mlp: Mlp) -> Self {
|
||||
fn new(rms_1: LayerNorm, attn: CausalSelfAttention, rms_2: LayerNorm, mlp: Mlp) -> Self {
|
||||
Self {
|
||||
rms_1,
|
||||
attn,
|
||||
@ -290,9 +264,9 @@ impl Block {
|
||||
fn load(vb: VarBuilder, cache: &Cache, cfg: &Config) -> Result<Self> {
|
||||
let attn = CausalSelfAttention::load(vb.pp("self_attn"), cache, cfg)?;
|
||||
let mlp = Mlp::load(vb.pp("mlp"), cfg)?;
|
||||
let input_layernorm = RmsNorm::load(cfg.dim, cfg.norm_eps, vb.pp("input_layernorm"))?;
|
||||
let input_layernorm = rms_norm(cfg.dim, cfg.norm_eps, vb.pp("input_layernorm"))?;
|
||||
let post_attention_layernorm =
|
||||
RmsNorm::load(cfg.dim, cfg.norm_eps, vb.pp("post_attention_layernorm"))?;
|
||||
rms_norm(cfg.dim, cfg.norm_eps, vb.pp("post_attention_layernorm"))?;
|
||||
Ok(Self::new(
|
||||
input_layernorm,
|
||||
attn,
|
||||
@ -305,7 +279,7 @@ impl Block {
|
||||
pub struct Llama {
|
||||
wte: Embedding,
|
||||
blocks: Vec<Block>,
|
||||
ln_f: RmsNorm,
|
||||
ln_f: LayerNorm,
|
||||
lm_head: Linear,
|
||||
pub config: Config,
|
||||
}
|
||||
@ -325,7 +299,7 @@ impl Llama {
|
||||
pub fn load(vb: VarBuilder, cache: &Cache, cfg: Config) -> Result<Self> {
|
||||
let wte = embedding(cfg.vocab_size, cfg.dim, vb.pp("model.embed_tokens"))?;
|
||||
let lm_head = linear(cfg.dim, cfg.vocab_size, vb.pp("lm_head"))?;
|
||||
let ln_f = RmsNorm::load(cfg.dim, cfg.norm_eps, vb.pp("model.norm"))?;
|
||||
let ln_f = rms_norm(cfg.dim, cfg.norm_eps, vb.pp("model.norm"))?;
|
||||
let blocks: Vec<_> = (0..cfg.n_layers)
|
||||
.map(|i| Block::load(vb.pp(&format!("model.layers.{i}")), cache, &cfg).unwrap())
|
||||
.collect();
|
||||
|
@ -1,6 +1,6 @@
|
||||
use candle::backend::BackendStorage;
|
||||
use candle::{CpuStorage, CustomOp1, DType, Device, IndexOp, Layout, Result, Shape, Tensor, D};
|
||||
use candle_nn::{Embedding, Linear, VarBuilder};
|
||||
use candle_nn::{rms_norm, Embedding, LayerNorm, Linear, VarBuilder};
|
||||
use cudarc::nccl::safe::{Comm, ReduceOp};
|
||||
use half::f16;
|
||||
use std::rc::Rc;
|
||||
@ -182,39 +182,6 @@ fn embedding(cfg: &Config, vb: VarBuilder) -> Result<Embedding> {
|
||||
Ok(Embedding::new(embeddings, cfg.hidden_size))
|
||||
}
|
||||
|
||||
struct RmsNorm {
|
||||
scale: Tensor,
|
||||
}
|
||||
|
||||
impl RmsNorm {
|
||||
fn load(size: usize, vb: VarBuilder) -> Result<Self> {
|
||||
let scale = vb.get(size, "weight")?;
|
||||
Ok(Self::new(scale))
|
||||
}
|
||||
|
||||
fn new(scale: Tensor) -> Self {
|
||||
Self { scale }
|
||||
}
|
||||
|
||||
fn forward(&self, x: &Tensor) -> Result<Tensor> {
|
||||
let in_dtype = x.dtype();
|
||||
// This is a no-op if x's dtype is already f32.
|
||||
let x = x.to_dtype(DType::F32)?;
|
||||
let (b_sz, seq_len, hidden_size) = x.shape().dims3()?;
|
||||
let norm_x = (x.sqr()?.sum_keepdim(2)? / hidden_size as f64)?;
|
||||
let norm_x = norm_x.broadcast_as((b_sz, seq_len, hidden_size))?;
|
||||
let x_normed = (x / (norm_x + 1e-5)?.sqrt()?)?;
|
||||
let size = self.scale.shape().dims1()?;
|
||||
let scale = self
|
||||
.scale
|
||||
.to_dtype(DType::F32)?
|
||||
.broadcast_as((b_sz, seq_len, size))?;
|
||||
let x = (scale * x_normed)?;
|
||||
let x = x.to_dtype(in_dtype)?;
|
||||
Ok(x)
|
||||
}
|
||||
}
|
||||
|
||||
struct CausalSelfAttention {
|
||||
qkv_proj: TensorParallelColumnLinear,
|
||||
o_proj: TensorParallelRowLinear,
|
||||
@ -369,14 +336,14 @@ impl Mlp {
|
||||
}
|
||||
|
||||
struct Block {
|
||||
rms_1: RmsNorm,
|
||||
rms_1: LayerNorm,
|
||||
attn: CausalSelfAttention,
|
||||
rms_2: RmsNorm,
|
||||
rms_2: LayerNorm,
|
||||
mlp: Mlp,
|
||||
}
|
||||
|
||||
impl Block {
|
||||
fn new(rms_1: RmsNorm, attn: CausalSelfAttention, rms_2: RmsNorm, mlp: Mlp) -> Self {
|
||||
fn new(rms_1: LayerNorm, attn: CausalSelfAttention, rms_2: LayerNorm, mlp: Mlp) -> Self {
|
||||
Self {
|
||||
rms_1,
|
||||
attn,
|
||||
@ -397,9 +364,9 @@ impl Block {
|
||||
fn load(vb: VarBuilder, cache: &Cache, cfg: &Config, comm: Rc<Comm>) -> Result<Self> {
|
||||
let attn = CausalSelfAttention::load(vb.pp("self_attn"), cache, cfg, comm.clone())?;
|
||||
let mlp = Mlp::load(vb.pp("mlp"), cfg, comm)?;
|
||||
let input_layernorm = RmsNorm::load(cfg.hidden_size, vb.pp("input_layernorm"))?;
|
||||
let input_layernorm = rms_norm(cfg.hidden_size, 1e-5, vb.pp("input_layernorm"))?;
|
||||
let post_attention_layernorm =
|
||||
RmsNorm::load(cfg.hidden_size, vb.pp("post_attention_layernorm"))?;
|
||||
rms_norm(cfg.hidden_size, 1e-5, vb.pp("post_attention_layernorm"))?;
|
||||
Ok(Self::new(
|
||||
input_layernorm,
|
||||
attn,
|
||||
|
@ -14,8 +14,7 @@ const MAX_SEQ_LEN: usize = 4096;
|
||||
const DEFAULT_PROMPT: &str = "My favorite theorem is ";
|
||||
|
||||
struct RmsNorm {
|
||||
scale: Tensor,
|
||||
eps: f64,
|
||||
inner: candle_nn::LayerNorm,
|
||||
span: tracing::Span,
|
||||
}
|
||||
|
||||
@ -23,26 +22,13 @@ impl RmsNorm {
|
||||
fn new(scale: QTensor) -> Result<Self> {
|
||||
let span = tracing::span!(tracing::Level::TRACE, "rms-norm");
|
||||
let scale = scale.dequantize(&Device::Cpu)?;
|
||||
Ok(Self {
|
||||
scale,
|
||||
eps: 1e-5,
|
||||
span,
|
||||
})
|
||||
let inner = candle_nn::LayerNorm::rms_norm(scale, 1e-5);
|
||||
Ok(Self { inner, span })
|
||||
}
|
||||
|
||||
fn forward(&self, x: &Tensor) -> Result<Tensor> {
|
||||
let _enter = self.span.enter();
|
||||
let (b_sz, seq_len, hidden_size) = x.dims3()?;
|
||||
let norm_x = (x.sqr()?.sum_keepdim(D::Minus1)? / hidden_size as f64)?;
|
||||
let norm_x = norm_x.broadcast_as((b_sz, seq_len, hidden_size))?;
|
||||
let x_normed = (x / (norm_x + self.eps)?.sqrt()?)?;
|
||||
let size = self.scale.dims1()?;
|
||||
let scale = self
|
||||
.scale
|
||||
.to_dtype(DType::F32)?
|
||||
.broadcast_as((b_sz, seq_len, size))?;
|
||||
let x = (scale * x_normed)?;
|
||||
Ok(x)
|
||||
self.inner.forward(x)
|
||||
}
|
||||
}
|
||||
|
||||
|
@ -30,17 +30,70 @@
|
||||
//! [`Layer Normalization`]: https://arxiv.org/abs/1607.06450
|
||||
use candle::{DType, Result, Tensor};
|
||||
|
||||
#[derive(Debug, Clone, Copy, PartialEq)]
|
||||
pub struct LayerNormConfig {
|
||||
pub eps: f64,
|
||||
/// Whether to remove the mean or not, the default is true and when set to false, this turns
|
||||
/// this layer into RmsNorm.
|
||||
pub remove_mean: bool,
|
||||
pub affine: bool,
|
||||
}
|
||||
|
||||
impl Default for LayerNormConfig {
|
||||
fn default() -> Self {
|
||||
Self {
|
||||
eps: 1e-5,
|
||||
remove_mean: true,
|
||||
affine: true,
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl From<f64> for LayerNormConfig {
|
||||
fn from(eps: f64) -> Self {
|
||||
Self {
|
||||
eps,
|
||||
remove_mean: true,
|
||||
affine: true,
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// This layer norm version handles both weight and bias so removes the mean.
|
||||
#[derive(Debug)]
|
||||
pub struct LayerNorm {
|
||||
weight: Tensor,
|
||||
bias: Tensor,
|
||||
bias: Option<Tensor>,
|
||||
remove_mean: bool,
|
||||
eps: f64,
|
||||
}
|
||||
|
||||
impl LayerNorm {
|
||||
pub fn new(weight: Tensor, bias: Tensor, eps: f64) -> Self {
|
||||
Self { weight, bias, eps }
|
||||
Self {
|
||||
weight,
|
||||
bias: Some(bias),
|
||||
remove_mean: true,
|
||||
eps,
|
||||
}
|
||||
}
|
||||
|
||||
pub fn new_no_bias(weight: Tensor, eps: f64) -> Self {
|
||||
Self {
|
||||
weight,
|
||||
bias: None,
|
||||
remove_mean: true,
|
||||
eps,
|
||||
}
|
||||
}
|
||||
|
||||
pub fn rms_norm(weight: Tensor, eps: f64) -> Self {
|
||||
Self {
|
||||
weight,
|
||||
bias: None,
|
||||
remove_mean: false,
|
||||
eps,
|
||||
}
|
||||
}
|
||||
|
||||
pub fn forward(&self, x: &Tensor) -> Result<Tensor> {
|
||||
@ -51,20 +104,47 @@ impl LayerNorm {
|
||||
};
|
||||
let (_bsize, _seq_len, hidden_size) = x.dims3()?;
|
||||
let x = x.to_dtype(internal_dtype)?;
|
||||
let mean_x = (x.sum_keepdim(2)? / hidden_size as f64)?;
|
||||
let x = x.broadcast_sub(&mean_x)?;
|
||||
let x = if self.remove_mean {
|
||||
let mean_x = (x.sum_keepdim(2)? / hidden_size as f64)?;
|
||||
x.broadcast_sub(&mean_x)?
|
||||
} else {
|
||||
x
|
||||
};
|
||||
let norm_x = (x.sqr()?.sum_keepdim(2)? / hidden_size as f64)?;
|
||||
let x_normed = x.broadcast_div(&(norm_x + self.eps)?.sqrt()?)?;
|
||||
let x = x_normed
|
||||
.to_dtype(x_dtype)?
|
||||
.broadcast_mul(&self.weight)?
|
||||
.broadcast_add(&self.bias)?;
|
||||
Ok(x)
|
||||
let x = x_normed.to_dtype(x_dtype)?.broadcast_mul(&self.weight)?;
|
||||
match &self.bias {
|
||||
None => Ok(x),
|
||||
Some(bias) => x.broadcast_add(bias),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
pub fn layer_norm(size: usize, eps: f64, vb: crate::VarBuilder) -> Result<LayerNorm> {
|
||||
pub fn layer_norm<C: Into<LayerNormConfig>>(
|
||||
size: usize,
|
||||
config: C,
|
||||
vb: crate::VarBuilder,
|
||||
) -> Result<LayerNorm> {
|
||||
let config = config.into();
|
||||
let weight = vb.get_or_init(size, "weight", crate::Init::Const(1.))?;
|
||||
let bias = vb.get_or_init(size, "bias", crate::Init::Const(0.))?;
|
||||
Ok(LayerNorm::new(weight, bias, eps))
|
||||
let bias = if config.affine {
|
||||
Some(vb.get_or_init(size, "bias", crate::Init::Const(0.))?)
|
||||
} else {
|
||||
None
|
||||
};
|
||||
Ok(LayerNorm {
|
||||
weight,
|
||||
bias,
|
||||
remove_mean: config.remove_mean,
|
||||
eps: config.eps,
|
||||
})
|
||||
}
|
||||
|
||||
pub fn rms_norm(size: usize, eps: f64, vb: crate::VarBuilder) -> Result<LayerNorm> {
|
||||
let config = LayerNormConfig {
|
||||
eps,
|
||||
remove_mean: false,
|
||||
affine: false,
|
||||
};
|
||||
layer_norm(size, config, vb)
|
||||
}
|
||||
|
@ -17,7 +17,7 @@ pub use conv::{conv1d, conv2d, Conv1d, Conv1dConfig, Conv2d, Conv2dConfig};
|
||||
pub use embedding::{embedding, Embedding};
|
||||
pub use group_norm::{group_norm, GroupNorm};
|
||||
pub use init::Init;
|
||||
pub use layer_norm::{layer_norm, LayerNorm};
|
||||
pub use layer_norm::{layer_norm, rms_norm, LayerNorm, LayerNormConfig};
|
||||
pub use linear::{linear, linear_no_bias, Linear};
|
||||
pub use optim::{AdamW, ParamsAdamW, SGD};
|
||||
pub use var_builder::{VarBuilder, VarMap};
|
||||
|
@ -1,5 +1,5 @@
|
||||
use candle::{DType, Device, IndexOp, Result, Tensor, D};
|
||||
use candle_nn::{Embedding, Linear, VarBuilder};
|
||||
use candle_nn::{rms_norm, Embedding, LayerNorm, Linear, VarBuilder};
|
||||
use std::collections::HashMap;
|
||||
use std::sync::{Arc, Mutex};
|
||||
|
||||
@ -71,32 +71,6 @@ fn embedding(cfg: &Config, vb: VarBuilder) -> Result<Embedding> {
|
||||
Ok(Embedding::new(embeddings, cfg.dim))
|
||||
}
|
||||
|
||||
struct RmsNorm {
|
||||
scale: Tensor,
|
||||
eps: f64,
|
||||
}
|
||||
|
||||
impl RmsNorm {
|
||||
fn load(size: usize, eps: f64, vb: VarBuilder) -> Result<Self> {
|
||||
let scale = vb.get(size, "weight")?;
|
||||
Ok(Self { scale, eps })
|
||||
}
|
||||
|
||||
fn forward(&self, x: &Tensor) -> Result<Tensor> {
|
||||
let (b_sz, seq_len, hidden_size) = x.dims3()?;
|
||||
let norm_x = (x.sqr()?.sum_keepdim(D::Minus1)? / hidden_size as f64)?;
|
||||
let norm_x = norm_x.broadcast_as((b_sz, seq_len, hidden_size))?;
|
||||
let x_normed = (x / (norm_x + self.eps)?.sqrt()?)?;
|
||||
let size = self.scale.dims1()?;
|
||||
let scale = self
|
||||
.scale
|
||||
.to_dtype(DType::F32)?
|
||||
.broadcast_as((b_sz, seq_len, size))?;
|
||||
let x = (scale * x_normed)?;
|
||||
Ok(x)
|
||||
}
|
||||
}
|
||||
|
||||
struct CausalSelfAttention {
|
||||
q_proj: Linear,
|
||||
k_proj: Linear,
|
||||
@ -239,14 +213,14 @@ impl Mlp {
|
||||
}
|
||||
|
||||
struct Block {
|
||||
rms_1: RmsNorm,
|
||||
rms_1: LayerNorm,
|
||||
attn: CausalSelfAttention,
|
||||
rms_2: RmsNorm,
|
||||
rms_2: LayerNorm,
|
||||
mlp: Mlp,
|
||||
}
|
||||
|
||||
impl Block {
|
||||
fn new(rms_1: RmsNorm, attn: CausalSelfAttention, rms_2: RmsNorm, mlp: Mlp) -> Self {
|
||||
fn new(rms_1: LayerNorm, attn: CausalSelfAttention, rms_2: LayerNorm, mlp: Mlp) -> Self {
|
||||
Self {
|
||||
rms_1,
|
||||
attn,
|
||||
@ -267,9 +241,9 @@ impl Block {
|
||||
fn load(vb: VarBuilder, cache: &Cache, cfg: &Config) -> Result<Self> {
|
||||
let attn = CausalSelfAttention::load(vb.pp("self_attn"), cache, cfg)?;
|
||||
let mlp = Mlp::load(vb.pp("mlp"), cfg)?;
|
||||
let input_layernorm = RmsNorm::load(cfg.dim, cfg.norm_eps, vb.pp("input_layernorm"))?;
|
||||
let input_layernorm = rms_norm(cfg.dim, cfg.norm_eps, vb.pp("input_layernorm"))?;
|
||||
let post_attention_layernorm =
|
||||
RmsNorm::load(cfg.dim, cfg.norm_eps, vb.pp("post_attention_layernorm"))?;
|
||||
rms_norm(cfg.dim, cfg.norm_eps, vb.pp("post_attention_layernorm"))?;
|
||||
Ok(Self::new(
|
||||
input_layernorm,
|
||||
attn,
|
||||
@ -282,12 +256,12 @@ impl Block {
|
||||
pub struct Llama {
|
||||
wte: Embedding,
|
||||
blocks: Vec<Block>,
|
||||
ln_f: RmsNorm,
|
||||
ln_f: LayerNorm,
|
||||
lm_head: Linear,
|
||||
}
|
||||
|
||||
impl Llama {
|
||||
fn new(wte: Embedding, blocks: Vec<Block>, ln_f: RmsNorm, lm_head: Linear) -> Self {
|
||||
fn new(wte: Embedding, blocks: Vec<Block>, ln_f: LayerNorm, lm_head: Linear) -> Self {
|
||||
Self {
|
||||
wte,
|
||||
blocks,
|
||||
@ -311,7 +285,7 @@ impl Llama {
|
||||
pub fn load(vb: VarBuilder, cache: &Cache, cfg: &Config) -> Result<Self> {
|
||||
let wte = embedding(cfg, vb.pp("model.embed_tokens"))?;
|
||||
let lm_head = linear(cfg.dim, cfg.vocab_size, vb.pp("lm_head"))?;
|
||||
let norm = RmsNorm::load(cfg.dim, cfg.norm_eps, vb.pp("model.norm"))?;
|
||||
let norm = rms_norm(cfg.dim, cfg.norm_eps, vb.pp("model.norm"))?;
|
||||
let blocks: Vec<_> = (0..cfg.n_layers)
|
||||
.map(|i| Block::load(vb.pp(&format!("model.layers.{i}")), cache, cfg).unwrap())
|
||||
.collect();
|
||||
|
Reference in New Issue
Block a user