// Copyright 2024 Google LLC // SPDX-License-Identifier: Apache-2.0 // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // https://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. // SIMD functions for Gemma/Griffin transformers. // Include guard (still compiled once per target) #if defined(THIRD_PARTY_GEMMA_CPP_GEMMA_GEMMA_INL_H_) == \ defined(HWY_TARGET_TOGGLE) #ifdef THIRD_PARTY_GEMMA_CPP_GEMMA_GEMMA_INL_H_ #undef THIRD_PARTY_GEMMA_CPP_GEMMA_GEMMA_INL_H_ #else #define THIRD_PARTY_GEMMA_CPP_GEMMA_GEMMA_INL_H_ #endif #include #include #include // std::min #include #include #include #include "gemma/activations.h" #include "gemma/common.h" #include "gemma/configs.h" #include "gemma/gemma.h" #include "gemma/weights.h" // Placeholder for internal test4, do not remove #include "ops/matmul-inl.h" #include "ops/matvec-inl.h" #include "ops/ops-inl.h" #include "util/threading.h" #include "hwy/aligned_allocator.h" #include "hwy/base.h" #include "hwy/bit_set.h" #include "hwy/contrib/thread_pool/thread_pool.h" #include "hwy/highway.h" #include "hwy/profiler.h" #include "hwy/timer.h" #ifndef GEMMA_CONFIG #if HWY_IDE // Provide a definition so the IDE does not complain. #define GEMMA_CONFIG ConfigGemmaTiny #else #error "Only include from instantiations/*.cc, which must define GEMMA_CONFIG" #endif // HWY_IDE #endif // GEMMA_CONFIG HWY_BEFORE_NAMESPACE(); namespace gcpp { namespace HWY_NAMESPACE { // Different functions use different naming conventions for the number of // tokens. Functions that are query-independent, such as RMSNorm*, call the // count `num_interleaved`. Functions that are query-dependent, such as // `Attention`, use separate `num_tokens` and `num_queries`. template HWY_NOINLINE void GriffinRecurrent( size_t batch_start, size_t num_tokens, size_t num_queries, size_t layer, Activations& activations, const CompressedLayer* layer_weights, const KVCaches& kv_caches, hwy::ThreadPool& pool) { PROFILER_ZONE("Gen.Griffin"); HWY_ASSERT(num_queries == 1); // TODO: add batch query support for Griffin. KVCache& kv_cache = kv_caches[0]; namespace hn = hwy::HWY_NAMESPACE; using D = hn::ScalableTag; static constexpr size_t kModelDim = TConfig::kModelDim; static constexpr size_t kConv1dWidth = TConfig::kConv1dWidth; static constexpr size_t kHeads = TConfig::kHeads; // X / Y linear layers. for (size_t batch_idx = 0; batch_idx < num_tokens; ++batch_idx) { float* HWY_RESTRICT y = activations.griffin_y.Batch(batch_idx); float* HWY_RESTRICT x = activations.griffin_x.Batch(batch_idx); TwoMatVecAdd( layer_weights->griffin.linear_x_w, layer_weights->griffin.linear_y_w, 0, activations.pre_att_rms_out.Batch(batch_idx), /*add0=*/layer_weights->griffin.linear_x_biases.data_scale1(), /*add1=*/layer_weights->griffin.linear_y_biases.data_scale1(), /*out0=*/x, /*out1=*/y, pool); Gelu(y, kModelDim); } // Conv1D. for (size_t batch_idx = 0; batch_idx < num_tokens; ++batch_idx) { const size_t pos = batch_start + batch_idx; float* HWY_RESTRICT x = activations.griffin_x.Batch(batch_idx); HWY_FULL(float) df; HWY_DASSERT(kModelDim % hn::Lanes(df) == 0); const size_t layer_offset = layer * kModelDim * (kConv1dWidth - 1); // cache[i] = input at time t-i. float* HWY_RESTRICT cache[HWY_MAX(kConv1dWidth, 1)]; cache[0] = x; for (size_t i = 1; i < kConv1dWidth; i++) { cache[i] = kv_cache.conv1d_cache.get() + layer_offset + ((pos + kConv1dWidth - 1 - i) % (kConv1dWidth - 1)) * kModelDim; } for (size_t i = 0; i < kModelDim; i += hn::Lanes(df)) { auto xv = hn::Load(df, x + i); auto accum0 = hn::Load(df, layer_weights->griffin.conv_biases.data_scale1() + i); auto accum1 = hn::Zero(df); static_assert(kConv1dWidth % 2 == 0, "Conv width must be even"); for (size_t l = 0; 2 * l < kConv1dWidth; l++) { auto wv0 = hn::Load(df, layer_weights->griffin.conv_w.data_scale1() + (kConv1dWidth - 1 - 2 * l) * kModelDim + i); auto wv1 = hn::Load(df, layer_weights->griffin.conv_w.data_scale1() + (kConv1dWidth - 2 - 2 * l) * kModelDim + i); accum0 = hn::MulAdd(wv0, hn::Load(df, cache[l * 2] + i), accum0); accum1 = hn::MulAdd(wv1, hn::Load(df, cache[l * 2 + 1] + i), accum1); } hn::Store(hn::Add(accum0, accum1), df, x + i); hn::Store(xv, df, cache[HWY_MAX(kConv1dWidth, 1) - 1] + i); } } // RGLRU for (size_t batch_idx = 0; batch_idx < num_tokens; ++batch_idx) { const size_t pos = batch_start + batch_idx; float* HWY_RESTRICT y = activations.griffin_y.Batch(batch_idx); float* HWY_RESTRICT x = activations.griffin_x.Batch(batch_idx); float* HWY_RESTRICT gate_x = activations.griffin_gate_x.Batch(batch_idx); float* HWY_RESTRICT a = activations.griffin_multiplier.Batch(batch_idx); float* HWY_RESTRICT rnn_state = kv_cache.rglru_cache.get() + layer * kModelDim; pool.Run(0, kHeads, [&](const uint64_t head, size_t /*thread*/) HWY_ATTR { constexpr size_t kHeadDim = kModelDim / kHeads; constexpr size_t kMatrixSize = kHeadDim * kHeadDim; size_t head_offset = head * kHeadDim; TwoOfsMatVecAddLoop( layer_weights->griffin.gate_w, kMatrixSize * head, kMatrixSize * (kHeads + head), x + head_offset, /*add0=*/layer_weights->griffin.gate_biases.data_scale1() + head_offset, /*add1=*/layer_weights->griffin.gate_biases.data_scale1() + kModelDim + head_offset, /*out0=*/gate_x + head_offset, /*out1=*/a + head_offset); Sigmoid(gate_x + head_offset, kHeadDim); Sigmoid(a + head_offset, kHeadDim); const auto fn_mul = [](D d, hn::Vec x, hn::Vec gate_x) HWY_ATTR { return hn::Mul(x, gate_x); }; hn::Transform1(D(), a + head_offset, kHeadDim, layer_weights->griffin.a.data_scale1() + head_offset, fn_mul); hn::Transform1(D(), x + head_offset, kHeadDim, gate_x + head_offset, fn_mul); // RNN scan HWY_FULL(float) df; HWY_DASSERT(kHeadDim % hn::Lanes(df) == 0); for (size_t i = 0; i < kHeadDim; i += hn::Lanes(df)) { auto log_a = hn::Load(df, a + head_offset + i); auto gated_x = hn::Load(df, x + head_offset + i); auto rnn = hn::Load(df, rnn_state + head_offset + i); auto a = hn::Exp(df, log_a); auto x_multiplier = hn::Sqrt(hn::NegMulAdd(a, a, hn::Set(df, 1.0f))); if (pos == 0) { x_multiplier = hn::Set(df, 1.0f); } auto new_x = hn::MulAdd(x_multiplier, gated_x, hn::Mul(a, rnn)); hn::Store(new_x, df, rnn_state + head_offset + i); // Join branches. auto yv = hn::Load(df, y + head_offset + i); auto pre_out = hn::Mul(yv, new_x); hn::Store(pre_out, df, x + head_offset + i); } }); } // Final linear layer. for (size_t batch_idx = 0; batch_idx < num_tokens; ++batch_idx) { float* HWY_RESTRICT x = activations.griffin_x.Batch(batch_idx); float* out_ptr = activations.att_sums.Batch(batch_idx); MatVecAdd( layer_weights->griffin.linear_out_w, 0, x, layer_weights->griffin.linear_out_biases.data_scale1(), activations.even_odd.All(), out_ptr, pool); } } // Wrapper class; holds arguments in member variables to shorten call sites. template class GemmaAttention { static constexpr size_t kCacheLayerSize = CacheLayerSize()(); static constexpr size_t kCachePosSize = CachePosSize()(); static constexpr size_t kHeads = TConfig::kHeads; static constexpr size_t kKVHeads = TConfig::kKVHeads; static constexpr size_t kModelDim = TConfig::kModelDim; static constexpr size_t kQKVDim = TConfig::kQKVDim; static constexpr size_t kQStride = Activations::QStride(); static constexpr size_t kSeqLen = TConfig::kSeqLen; static constexpr bool kIsMHA = Activations::IsMHA(); // The attention window usually starts at 0 unless unless `pos` is larger than // the attention window size, then it is `pos` - window_size + 1. static HWY_INLINE size_t StartPos(size_t pos, size_t layer) { const size_t att_window_size = TConfig::kAttentionWindowSizes[layer]; return pos - std::min(att_window_size - 1, pos); } template HWY_INLINE void PositionalEncodingQK(const T* qk, size_t pos, size_t layer, const float mul, T* qk_out) { const float* inv_timescale = activations_.inv_timescale.Const(); // PostQKType::Rope (void)layer; if (TConfig::kUseHalfRope) { hwy::CopyBytes(qk, qk_out, kQKVDim * sizeof(*qk)); Rope(qk_out, kQKVDim / 2, inv_timescale, pos); MulByConst(mul, qk_out, kQKVDim); } else { RopeAndMulBy(mul, qk, kQKVDim, inv_timescale, pos, qk_out); } } // Fills activations.q and computes KV. For kIsMHA, a single MatMul suffices // and we later copy KV from q to KVCache. Otherwise, a second MatMul writes // KV directly to KVCache. HWY_NOINLINE void ComputeQKV(const size_t batch_start, const size_t num_interleaved) { PROFILER_ZONE("Gen.Attention.QKV"); // For the computation of Q, K, and V, it is useful to remember that // qkv_einsum_w has shape [(kHeads + kKVHeads * 2), kKQVDim, kModelDim] // and kQStride = kQKVDim * (kIsMHA ? 3 : 1); const auto pre_att_rms_out = MakeMat(activations_.pre_att_rms_out.All(), kModelDim); MatMul_4x4( num_interleaved, pre_att_rms_out, MakeMat(layer_weights_.qkv_einsum_w.data(), kModelDim), layer_weights_.qkv_einsum_w.scale(), /*add=*/nullptr, MakeMat(activations_.q.All(), kHeads * kQStride), pool_); if constexpr (kIsMHA) { static_assert(TConfig::kInterleaveQKV, "MHA implies interleaved"); // Multi-Head Attention a.k.a. "use_qkv_einsum" computed QKV already. } else { // Single query and no wraparound means we can use a matmul and write // directly into the KV cache with a stride of kCachePosSize. if (num_queries_ == 1 && batch_start + num_tokens_ <= div_seq_len_.GetDivisor()) { const size_t kv_ofs = batch_start * kCachePosSize + layer_ * kCacheLayerSize; // KV structure is [k, v, k, v, ....] = kKVHeads pairs of (k, v). float* HWY_RESTRICT kv = kv_caches_[0].kv_cache.get() + kv_ofs; MatMul_4x4( num_tokens_, pre_att_rms_out, MakeMat(layer_weights_.qkv_einsum_w.data(), kModelDim, kModelDim, kHeads * kQKVDim * kModelDim), layer_weights_.qkv_einsum_w.scale(), /*add=*/nullptr, MakeMat(kv, kKVHeads * 2 * kQKVDim, kCachePosSize), pool_); } else { // Proceed row by row because there will be wraparound. for (size_t interleaved_idx = 0; interleaved_idx < num_interleaved; ++interleaved_idx) { const float* x = activations_.pre_att_rms_out.Batch(interleaved_idx); const size_t query_idx = interleaved_idx % num_queries_; const size_t batch_idx = interleaved_idx / num_queries_; KVCache& kv_cache = kv_caches_[query_idx]; const size_t cache_pos = div_seq_len_.Remainder(batch_start + batch_idx); const size_t kv_offset = cache_pos * kCachePosSize + layer_ * kCacheLayerSize; float* HWY_RESTRICT kv = kv_cache.kv_cache.get() + kv_offset; // KV structure is [k, v, k, v, ....] = kKVHeads pairs of (k, v). MatVec( layer_weights_.qkv_einsum_w, kHeads * kQKVDim * kModelDim, x, activations_.even_odd.All(), kv, pool_); } } } // Apply positional encodings for K (and copy KV to cache if MHA). pool_.Run( 0, kKVHeads * num_interleaved, [&](uint64_t task, size_t /*thread*/) HWY_ATTR { const size_t head = task % kKVHeads; const size_t interleaved_idx = task / kKVHeads; const size_t query_idx = interleaved_idx % num_queries_; const size_t batch_idx = interleaved_idx / num_queries_; const size_t pos = batch_start + batch_idx; const size_t cache_pos = div_seq_len_.Remainder(pos); const size_t kv_offset = cache_pos * kCachePosSize + layer_ * kCacheLayerSize + head * kQKVDim * 2; KVCache& kv_cache = kv_caches_[query_idx]; float* HWY_RESTRICT kv = kv_cache.kv_cache.get() + kv_offset; const float* HWY_RESTRICT mha_kv = activations_.q.Batch(interleaved_idx) + head * kQStride + kQKVDim; // Copy from `q` if MHA, or apply in-place. PositionalEncodingQK(kIsMHA ? mha_kv : kv, pos, layer_, 1.0f, kv); // If MHA, also copy V into KVCache. if (kIsMHA) { hwy::CopyBytes(mha_kv + kQKVDim, kv + kQKVDim, kQKVDim * sizeof(*kv)); } }); } // Computes Q.K scores, which are "logits" (or scores) stored to head_att. HWY_INLINE void QDotK(const size_t start_pos, const size_t pos, const size_t head_offset, const float* HWY_RESTRICT q, const KVCache& kv_cache, float* HWY_RESTRICT head_att) { if (HWY_LIKELY(pos <= kSeqLen)) { // Slightly faster: no wraparound. for (size_t pos2 = start_pos; pos2 <= pos; ++pos2) { const size_t kv_offset = pos2 * kCachePosSize + layer_ * kCacheLayerSize + head_offset; const float* HWY_RESTRICT k = &kv_cache.kv_cache[kv_offset]; const float score = Dot(q, k, kQKVDim); head_att[pos2] = score; } } else { for (size_t pos2 = start_pos; pos2 <= pos; ++pos2) { const size_t cache_pos = div_seq_len_.Remainder(pos2); const size_t kv_offset = cache_pos * kCachePosSize + layer_ * kCacheLayerSize + head_offset; const float* HWY_RESTRICT k = &kv_cache.kv_cache[kv_offset]; const float score = Dot(q, k, kQKVDim); head_att[pos2 % kSeqLen] = score; } } } // Accumulates the sum of v (from `kv_cache`) * probability (`head_att`) into // `att_out`. Equivalent in gemma/modules.py: // encoded = jnp.einsum('BTNS,BSNH->BTNH', probs, value_proj) static HWY_INLINE void WeightedSumV(const size_t start_pos, const size_t pos, const float* HWY_RESTRICT head_att, const size_t layer, const size_t head_offset, const hwy::Divisor& div_seq_len, const KVCache& kv_cache, float* HWY_RESTRICT att_out) { hwy::ZeroBytes(att_out, kQKVDim * sizeof(*att_out)); if (HWY_LIKELY(pos <= kSeqLen)) { // Slightly faster: no wraparound. for (size_t pos2 = start_pos; pos2 <= pos; ++pos2) { const size_t kv_offset = pos2 * kCachePosSize + layer * kCacheLayerSize + head_offset; const float* HWY_RESTRICT v = kv_cache.kv_cache.get() + kv_offset + kQKVDim; MulByConstAndAdd(head_att[pos2], v, att_out, kQKVDim); } } else { for (size_t pos2 = start_pos; pos2 <= pos; ++pos2) { const size_t cache_pos = div_seq_len.Remainder(pos2); const size_t kv_offset = cache_pos * kCachePosSize + layer * kCacheLayerSize + head_offset; const float* HWY_RESTRICT v = kv_cache.kv_cache.get() + kv_offset + kQKVDim; MulByConstAndAdd(head_att[pos2 % kSeqLen], v, att_out, kQKVDim); } } } HWY_NOINLINE void DotSoftmaxWeightedSum(const size_t batch_start, const size_t num_interleaved) { PROFILER_ZONE("Gen.Attention.DotSoftmax"); GEMMA_CONSTEXPR_SQRT float kQueryScale = ChooseQueryScale(); // A "head group" in the context of GQA refers to a collection of query // heads that share the same key and value heads. static_assert((kHeads % kKVHeads) == 0, "query heads must be a multiple of key-value heads"); constexpr size_t kHeadGroups = kHeads / kKVHeads; // For each head (token, query), compute Q.K, softmax, and weighted V. pool_.Run(0, kHeads * num_interleaved, [&](uint64_t task, size_t /*thread*/) HWY_ATTR { const size_t head = task % kHeads; const size_t interleaved_idx = task / kHeads; const size_t query_idx = interleaved_idx % num_queries_; const size_t batch_idx = interleaved_idx / num_queries_; const size_t head_offset = (head / kHeadGroups) * kQKVDim * 2; KVCache& kv_cache = kv_caches_[query_idx]; float* HWY_RESTRICT q = activations_.q.Batch(interleaved_idx) + head * kQStride; // Apply rope and scaling to Q. const size_t pos = batch_start + batch_idx; PositionalEncodingQK(q, pos, layer_, kQueryScale, q); const size_t start_pos = StartPos(pos, layer_); float* HWY_RESTRICT head_att = activations_.att.Batch(interleaved_idx) + head * kSeqLen; QDotK(start_pos, pos, head_offset, q, kv_cache, head_att); // SoftMax with optional SoftCap yields "probabilities" in // head_att. const size_t head_att_len = std::min(pos + 1, kSeqLen); MaybeLogitsSoftCap(TConfig::kAttCap, head_att, head_att_len); Softmax(head_att, head_att_len); float* HWY_RESTRICT att_out = activations_.att_out.Batch(interleaved_idx) + head * kQKVDim; WeightedSumV(start_pos, pos, head_att, layer_, head_offset, div_seq_len_, kv_cache, att_out); }); } // Sums encoded (`att_out`) over num_heads (`kHeads`) and head_dim (`kQKVDim`) // into output (`layer_out`). HWY_NOINLINE void SumHeads(const size_t num_interleaved) { PROFILER_ZONE("Gen.Attention.SumHeads"); constexpr bool kAdd = TConfig::kSoftmaxAttnOutputBiases; const float* bias = kAdd ? layer_weights_.attention_output_biases.data_scale1() : nullptr; // att_weights and att_out are concatenated heads, each of length kQKVDim. // Thus the [num_interleaved, kModelDim] matmul output is the sum over // heads. Compare gemma/modules.py: // attn_output = self.attn_vec_einsum('BTNH,NHD->BTD', encoded) MatMul_4x4( num_interleaved, MakeMat(activations_.att_out.All(), kHeads * kQKVDim), MakeMat(layer_weights_.att_weights.data(), kHeads * kQKVDim), layer_weights_.attn_vec_einsum_w.scale(), bias, MakeMat(activations_.att_sums.All(), kModelDim), pool_); } public: GemmaAttention(size_t interleaved_start, size_t num_tokens, size_t num_queries, size_t layer, Activations& activations, const CompressedLayer* layer_weights, const hwy::Divisor& div_seq_len, const KVCaches& kv_caches, hwy::ThreadPool& pool) : interleaved_start_(interleaved_start), num_tokens_(num_tokens), num_queries_(num_queries), layer_(layer), activations_(activations), layer_weights_(*layer_weights), div_seq_len_(div_seq_len), kv_caches_(kv_caches), pool_(pool) { HWY_DASSERT(interleaved_start_ % num_queries_ == 0); HWY_DASSERT(num_queries_ <= kv_caches_.size()); } HWY_INLINE void operator()() { const size_t batch_start = interleaved_start_ / num_queries_; const size_t num_interleaved = num_tokens_ * num_queries_; ComputeQKV(batch_start, num_interleaved); DotSoftmaxWeightedSum(batch_start, num_interleaved); SumHeads(num_interleaved); } private: const size_t interleaved_start_; const size_t num_tokens_; const size_t num_queries_; const size_t layer_; Activations& activations_; const CompressedLayer& layer_weights_; const hwy::Divisor& div_seq_len_; const KVCaches& kv_caches_; hwy::ThreadPool& pool_; }; template HWY_NOINLINE void Attention(LayerAttentionType type, size_t interleaved_start, size_t num_tokens, size_t num_queries, size_t layer, Activations& activations, const CompressedLayer* layer_weights, const hwy::Divisor& div_seq_len, const KVCaches& kv_caches, hwy::ThreadPool& pool) { if (type == LayerAttentionType::kGemma) { GemmaAttention(interleaved_start, num_tokens, num_queries, layer, activations, layer_weights, div_seq_len, kv_caches, pool)(); } else { // Only reached if the model is Griffin. `if constexpr` prevents generating // this code for non-Griffin models. if constexpr (TConfig::kGriffinLayers > 0) { HWY_ASSERT(num_queries == 1); GriffinRecurrent(interleaved_start, num_tokens, num_queries, layer, activations, layer_weights, kv_caches, pool); } } } template HWY_NOINLINE void Activation(T* HWY_RESTRICT c1, T* HWY_RESTRICT c2, size_t count) { PROFILER_ZONE("Gen.Activation"); namespace hn = hwy::HWY_NAMESPACE; using DF = hn::ScalableTag; using VF = hn::Vec; // ActivationType::Gelu hn::Transform1(DF(), c1, count, c2, [](DF df, VF v, VF mul) HWY_ATTR { return hn::Mul(mul, Gelu(df, v)); }); } template HWY_NOINLINE void FFW(Activations& activations, size_t num_interleaved, const CompressedLayer* layer_weights, hwy::ThreadPool& pool) { PROFILER_ZONE("Gen.FFW"); constexpr size_t kModelDim = TConfig::kModelDim; constexpr size_t kFFHiddenDim = TConfig::kFFHiddenDim; // MatMul expects col-major B, which is what we have: kModelDim consecutive // elements in memory, repeated kFFHiddenDim times. HWY_DASSERT(num_interleaved <= activations.bf_pre_ffw_rms_out.BatchSize()); const auto A = MakeMat(activations.bf_pre_ffw_rms_out.All(), kModelDim); const auto B1 = MakeMat(layer_weights->gating_einsum_w.data(), kModelDim); const auto B2 = MakeMat(layer_weights->gating_einsum_w.data(), kModelDim, kModelDim, kModelDim * kFFHiddenDim); const float scale = layer_weights->gating_einsum_w.scale(); constexpr bool kAddBias = TConfig::kFFBiases; const float* bias1 = nullptr; const float* bias2 = nullptr; const float* output_bias = nullptr; if constexpr (kAddBias) { bias1 = layer_weights->ffw_gating_biases.data_scale1(); bias2 = bias1 + kFFHiddenDim; output_bias = layer_weights->ffw_output_biases.data_scale1(); } auto C1 = MakeMat(activations.C1.All(), kFFHiddenDim); auto C2 = MakeMat(activations.C2.All(), kFFHiddenDim); // Will go through GELU. MatMul_4x4(num_interleaved, A, B1, scale, bias1, C1, pool); // What to multiply by. MatMul_4x4(num_interleaved, A, B2, scale, bias2, C2, pool); // Activation (Gelu) and multiply by gate. Store activations in C1. Activation(C1.ptr, C2.ptr, kFFHiddenDim * num_interleaved); // Hidden layer -> output layer. MatMul_4x4(num_interleaved, C1, MakeMat(layer_weights->linear_w.data(), kFFHiddenDim), layer_weights->linear_w.scale(), output_bias, MakeMat(activations.ffw_out.All(), kModelDim), pool); } // `batch_idx` indicates which row of `x` to write to. // `pos` is the *token*'s position, not the start of the batch, because this is // called for batches of tokens in prefill, but batches of queries in decode. template HWY_NOINLINE void EmbedToken(int token, size_t batch_idx, size_t pos, const CompressedWeights& weights, RowVectorBatch& x) { constexpr size_t kModelDim = TConfig::kModelDim; GEMMA_CONSTEXPR_EMBSCALING const float kEmbScaling = EmbeddingScaling(); HWY_DASSERT(token >= 0); HWY_DASSERT(token < TConfig::kVocabSize); Decompress(weights.embedder_input_embedding, token * kModelDim, x.Batch(batch_idx), kModelDim); MulByConst(kEmbScaling, x.Batch(batch_idx), kModelDim); if constexpr (TConfig::kAbsolutePE) { AddAbsolutePositionalEmbeddings(x.Batch(batch_idx), kModelDim, pos); }; } template HWY_NOINLINE void ResidualConnection( size_t num_interleaved, T* HWY_RESTRICT other, T* HWY_RESTRICT x, const CompressedLayer* layer_weights, bool is_attention) { constexpr size_t kModelDim = TConfig::kModelDim; // ResidualType::Add AddFromBatched(num_interleaved, other, x, kModelDim); } template void PostNorm(size_t num_interleaved, const WeightT& weights, InOutT* inout) { if (TConfig::kPostNorm == PostNormType::Scale) { RMSNormInplaceBatched(num_interleaved, weights.data_scale1(), inout, TConfig::kModelDim); } } template HWY_NOINLINE void TransformerLayer( size_t num_tokens, size_t num_queries, size_t pos, size_t layer, const CompressedLayer* layer_weights, Activations& activations, const hwy::Divisor& div_seq_len, const KVCaches& kv_caches, hwy::ThreadPool& pool) { constexpr size_t kModelDim = TConfig::kModelDim; const size_t num_interleaved = num_tokens * num_queries; auto type = TConfig::kLayerConfig[layer]; size_t layer_of_type = NumLayersOfTypeBefore(TConfig::kLayerConfig, type, layer); RMSNormBatched(num_interleaved, activations.x.All(), layer_weights->pre_attention_norm_scale.data_scale1(), activations.pre_att_rms_out.All(), kModelDim); Attention(type, pos, num_tokens, num_queries, layer_of_type, activations, layer_weights, div_seq_len, kv_caches, pool); PostNorm(num_interleaved, layer_weights->post_attention_norm_scale, activations.att_sums.All()); ResidualConnection(num_interleaved, activations.att_sums.All(), activations.x.All(), layer_weights, /*is_attention=*/true); RMSNormBatched(num_interleaved, activations.x.All(), layer_weights->pre_ffw_norm_scale.data_scale1(), activations.bf_pre_ffw_rms_out.All(), kModelDim); FFW(activations, num_interleaved, layer_weights, pool); PostNorm(num_interleaved, layer_weights->post_ffw_norm_scale, activations.ffw_out.All()); ResidualConnection(num_interleaved, activations.ffw_out.All(), activations.x.All(), layer_weights, /*is_attention=*/false); } // Batches are important for amortizing loading weights over multiple tokens. // This is possible in prefill because we know all tokens beforehand, whereas // decode depends on the previous output token. However, each prefill batch of a // query requires that preceding batches already wrote to the KV cache, hence we // sequentially loop over token batches. We can reduce the number of iterations // by increasing the batch size, but this also increases arithmetic intensity, // and so we are eventually compute-limited. The tensor parallelism (number of // threads collaborating on MatMul) is also limited by the CPU topology: // fork/join barriers are slow(er) when some threads reside in a different NUMA // node. To allow more threads to help, we also support parallelizing over // queries in case GenerateBatch was called. // // Thus we have two-level parallelism: // - Outer: handles one 'qbatch' of entire queries. The set of outer workers // includes the main thread because it is the one that calls `Prefill`, and is // determined by the number of 'clusters' (shared L3 caches or sockets). // - Inner: each `outer` worker passes `inner_pools_[outer]` to // `TransformerLayer` for tensor-level parallelism, and processes // `tbatch_size` tokens from a single query at a time. // // This class holds the thread pools and one activation per outer worker. It is // NOT reused across calls to GenerateSingle/GenerateBatch so that we can adapt // to their num_queries. class PrefillState { public: // `tbatch_size` is the number of tokens from one query to prefill at a time. template void Init(size_t num_queries, size_t tbatch_size, PerClusterPools& pools) { PROFILER_ZONE("Init.Prefill"); HWY_ASSERT(num_queries != 0); HWY_ASSERT(activations_.empty()); // only call once. // Allocate one activation per query, not outer worker, because the common // case is a single query. If we allocate the lesser of the two, it is // unclear how to choose an unused activation in Prefill. activations_.resize(num_queries); if (num_queries == 1) { activations_[0].Allocate(tbatch_size); } else { // Allocating in parallel can save 30 ms. We might have more workers than // queries/tasks, so do not check the `thread` argument. pools.Outer().Run(0, num_queries, [this, tbatch_size](uint64_t qi, size_t /*thread*/) { activations_[qi].Allocate(tbatch_size); }); } } template HWY_NOINLINE void Prefill(const MultiplePromptsTokens& prompts, const size_t prefill_per_query, const size_t pos, const size_t query_idx_start, const CompressedWeights& weights, const RuntimeConfig& runtime_config, const hwy::Divisor& div_seq_len, const KVCaches& kv_caches, PerClusterPools& pools) { PROFILER_ZONE("Gen.Prefill"); const size_t num_queries = prompts.size(); HWY_ASSERT(kv_caches.size() == num_queries); const size_t max_tbatch_size = activations_[0].x.BatchSize(); // For each query (parallel): an outer worker processes all its tokens. // `qi` is relative to the batch, not the global query index. pools.Outer().Run( 0, num_queries, [&](const uint64_t qi, size_t qthread) HWY_ATTR { Activations& activations = activations_[qi]; hwy::ThreadPool& inner_pool = pools.Inner(qthread); // Single query at a time, so pass a slice of the KV cache because // GemmaAttention will only access the first. const size_t kPrefillQueries = 1; KVCaches prefill_kv_caches(&kv_caches[qi], kPrefillQueries); // For each batch of tokens in the query: for (size_t tbatch_start = 0; tbatch_start < prefill_per_query; tbatch_start += max_tbatch_size) { // Fill activations.x (much faster than TransformerLayer). const size_t tbatch_size = HWY_MIN(max_tbatch_size, prefill_per_query - tbatch_start); for (size_t ti = 0; ti < tbatch_size; ++ti) { const int token = prompts[qi][tbatch_start + ti]; EmbedToken(token, ti, pos + ti, weights, activations.x); } // Transformer with one batch of tokens from a single query. for (size_t layer = 0; layer < TConfig::kLayers; ++layer) { const auto* layer_weights = weights.GetLayer(layer); TransformerLayer(tbatch_size, kPrefillQueries, pos + tbatch_start, layer, layer_weights, activations, div_seq_len, prefill_kv_caches, inner_pool); } // NOTE: we unconditionally call StreamToken, even if EOS. for (size_t ti = 0; ti < tbatch_size; ++ti) { const int token = prompts[qi][tbatch_start + ti]; runtime_config.StreamToken(query_idx_start + qi, pos + tbatch_start + ti, token, 0.0f); } } // for tbatch_start }); } private: std::vector activations_; // One per query, filled by Init. }; // `tokens` is length `num_tokens * num_queries`. In autoregressive decode, // `num_tokens == 1`. template HWY_NOINLINE void Transformer(const int* tokens, size_t num_tokens, size_t num_queries, size_t pos, const CompressedWeights& weights, Activations& activations, const hwy::Divisor& div_seq_len, const KVCaches& kv_caches, hwy::ThreadPool& pool, const LayersOutputFunc& layers_output) { const size_t num_interleaved = num_tokens * num_queries; if (layers_output) { for (size_t token_idx = 0; token_idx < num_interleaved; ++token_idx) { const size_t query_idx = token_idx % num_queries; const size_t logical_pos = (pos + token_idx) / num_queries; const float token_f = tokens[token_idx]; layers_output(query_idx, logical_pos, "tokens", -1, &token_f, 1); } } constexpr size_t kModelDim = TConfig::kModelDim; for (size_t token_idx = 0; token_idx < num_interleaved; ++token_idx) { EmbedToken(tokens[token_idx], token_idx, pos, weights, activations.x); } for (size_t layer = 0; layer < TConfig::kLayers; ++layer) { const CompressedLayer* layer_weights = weights.GetLayer(layer); TransformerLayer(num_tokens, num_queries, pos, layer, layer_weights, activations, div_seq_len, kv_caches, pool); if (layers_output) { for (size_t token_idx = 0; token_idx < num_interleaved; ++token_idx) { const size_t logical_pos = (pos + token_idx) / num_queries; layers_output(token_idx % num_queries, logical_pos, "blocks", layer, activations.x.Batch(token_idx), kModelDim); } } } RMSNormInplaceBatched(num_interleaved, weights.final_norm_scale.data_scale1(), activations.x.All(), kModelDim); if (layers_output) { for (size_t token_idx = 0; token_idx < num_interleaved; ++token_idx) { const size_t query_idx = token_idx % num_queries; const size_t logical_pos = (pos + token_idx) / num_queries; layers_output(query_idx, logical_pos, "final_norm", -1, activations.x.Batch(token_idx), kModelDim); } } } template void RangeChecks(size_t& max_tokens, size_t& max_generated_tokens, size_t& prompt_size) { if (!TConfig::kUseLocalAttention) { if (max_tokens > TConfig::kSeqLen) { fprintf(stderr, "WARNING: max_tokens %zu > kSeqLen %d, truncating.\n", max_tokens, TConfig::kSeqLen); max_tokens = static_cast(TConfig::kSeqLen); } } if (max_generated_tokens > max_tokens) { fprintf(stderr, "WARNING: max_generated_tokens %zu > max_tokens %zu, truncating.\n", max_generated_tokens, max_tokens); max_generated_tokens = max_tokens - 1; } if (!TConfig::kUseLocalAttention) { if (prompt_size + max_generated_tokens > max_tokens) { fprintf(stderr, "WARNING: prompt_size %zu + max_generated_tokens %zu > " "max_tokens %zu, truncating to ", prompt_size, max_generated_tokens, max_tokens); prompt_size = std::min(prompt_size, max_tokens - max_generated_tokens); fprintf(stderr, "%zu\n", prompt_size); } } HWY_ASSERT(prompt_size > 0); } // Placeholder for internal test3, do not remove // Returns interleaved tokens: one from each query, followed by the second from // all queries, with EOS padding. static std::vector InterleaveQueries(const MultiplePromptsTokens& queries, const RuntimeConfig& runtime_config, size_t& min_prompt_size, size_t& max_prompt_size) { const size_t num_queries = queries.size(); min_prompt_size = hwy::LimitsMax(); max_prompt_size = 0; for (size_t i = 0; i < num_queries; ++i) { min_prompt_size = std::min(min_prompt_size, queries[i].size()); max_prompt_size = std::max(max_prompt_size, queries[i].size()); } std::vector prompt; prompt.reserve(max_prompt_size * num_queries); for (size_t pos = 0; pos < max_prompt_size; ++pos) { for (size_t q = 0; q < num_queries; ++q) { if (pos < queries[q].size()) { prompt.push_back(queries[q][pos]); } else { prompt.push_back(runtime_config.eos_id); } } } return prompt; } // Holds "is at end of stream" state for each query. class TokenStreamer { public: explicit TokenStreamer(const RuntimeConfig& runtime_config) : runtime_config_(runtime_config) {} // Returns whether the query was already at, or has just reached, the end of // the stream: either via token == eos_id, or StreamToken returning false. bool operator()(size_t query_idx, size_t pos, int token, float prob) { if (HWY_UNLIKELY(is_eos_.Get(query_idx))) return true; if (!runtime_config_.StreamToken(query_idx, pos, token, prob) || token == runtime_config_.eos_id) { is_eos_.Set(query_idx); return true; } return false; } private: const RuntimeConfig& runtime_config_; hwy::BitSet4096<> is_eos_; }; // Generates one token for each query in `prompts`, which is one qbatch whose // size is at most the `batch_size` passed to `activations.Allocate`. // // `pos` indexes the KV cache. In the first turn of a chat, pos = 0, and it // continues to increase by one for each prefilled/generated token per query. // // `query_idx_start` is the query_idx of the first query in the batch, so that // `StreamFunc` gets the global query index, not relative to the batch. // // `kv_caches` is for the batch, size must match `prompts`. template void GenerateT(const ByteStorageT& weights_u8, Activations& activations, const RuntimeConfig& runtime_config, const MultiplePromptsTokens& prompts, const size_t pos, const size_t query_idx_start, const KVCaches& kv_caches, PerClusterPools& pools, TimingInfo& timing_info) { constexpr size_t kModelDim = TConfig::kModelDim; constexpr size_t kVocabSize = TConfig::kVocabSize; const CompressedWeights& weights = *reinterpret_cast*>(weights_u8.get()); // TODO: remove once all parallel sections support hierarchical parallelism. hwy::ThreadPool& pool = pools.Inner(0); const size_t num_queries = prompts.size(); HWY_ASSERT(num_queries <= 4096); // TokenStreamer uses BitSet4096. HWY_ASSERT(num_queries <= activations.x.BatchSize()); HWY_ASSERT(kv_caches.size() == num_queries); const hwy::Divisor div_seq_len(static_cast(kv_caches[0].seq_len)); size_t min_prompt_size, max_prompt_size; const std::vector prompt = InterleaveQueries( prompts, runtime_config, min_prompt_size, max_prompt_size); size_t max_tokens = runtime_config.max_tokens; size_t max_generated_tokens = runtime_config.max_generated_tokens; RangeChecks(max_tokens, max_generated_tokens, max_prompt_size); if (pos >= max_tokens) { fprintf(stderr, "Warning: pos %zu >= max_tokens %zu, aborting.\n", pos, max_tokens); return; } // If no sample_func is provided, we use top-k sampling. const SampleFunc sample_token = runtime_config.sample_func ? runtime_config.sample_func : [&](const float* logits, size_t vocab_size) -> int { return SampleTopK(logits, vocab_size, *runtime_config.gen, runtime_config.temperature, runtime_config.accept_token); }; // Prefill stops before min_prompt_size - 1 because the last prompt token is // the first input token for generation. const size_t prefill_per_query = min_prompt_size - 1; double prefill_start; { // TODO: move to Gemma, reuse across calls to Generate. PrefillState prefill; prefill.Init(num_queries, runtime_config.prefill_tbatch_size, pools); prefill_start = hwy::platform::Now(); prefill.Prefill(prompts, prefill_per_query, pos, query_idx_start, weights, runtime_config, div_seq_len, kv_caches, pools); timing_info.NotifyPrefill(prefill_per_query * num_queries, prefill_start); } size_t interleaved_pos = (pos + prefill_per_query) * num_queries; // Storage for the last generated token from each query, passed to the next // Transformer() call. std::vector gen_tokens(num_queries); // Stream the last prompt token from each query and fill gen_tokens. TokenStreamer token_streamer(runtime_config); for (size_t query_idx = 0; query_idx < num_queries; ++query_idx) { gen_tokens[query_idx] = prompts[query_idx][prefill_per_query]; (void)token_streamer(query_idx_start + query_idx, prefill_per_query, gen_tokens[query_idx], 0.0f); } const double gen_start = hwy::platform::Now(); for (size_t gen_per_query = 0; gen_per_query < HWY_MIN(max_tokens, max_generated_tokens); ++gen_per_query) { // Decode: generate one token for each query. Transformer(gen_tokens.data(), /*num_tokens=*/1, num_queries, interleaved_pos, weights, activations, div_seq_len, kv_caches, pool, runtime_config.layers_output); interleaved_pos += num_queries; bool all_queries_eos = true; PROFILER_ZONE("Gen.Embedding"); // Compute logits from last layer activations. MatMul_4x4( num_queries, MakeMat(activations.x.All(), kModelDim), MakeMat(weights.embedder_input_embedding.data(), kModelDim), weights.embedder_input_embedding.scale(), /*add=*/nullptr, MakeMat(activations.logits.All(), kVocabSize), pool); for (size_t query_idx = 0; query_idx < num_queries; ++query_idx) { float* HWY_RESTRICT logits = activations.logits.Batch(query_idx); MaybeLogitsSoftCap(TConfig::kFinalCap, logits, kVocabSize); Softmax(logits, kVocabSize); const int token = sample_token(logits, kVocabSize); timing_info.NotifyGenerated(prefill_start, gen_start); const bool is_eos = token_streamer(query_idx_start + query_idx, prefill_per_query + 1 + gen_per_query, token, logits[token]); all_queries_eos &= is_eos; gen_tokens[query_idx] = is_eos ? runtime_config.eos_id : token; } if (all_queries_eos) break; } // foreach token to generate timing_info.NotifyGenerateDone(gen_start); } template void GenerateSingleT(const ByteStorageT& weights_u8, const RuntimeConfig& runtime_config, const PromptTokens& prompt, size_t pos, KVCache& kv_cache, PerClusterPools& pools, TimingInfo& timing_info) { const size_t num_queries = 1; const size_t qbatch_start = 0; Activations activations; activations.Allocate(num_queries); const MultiplePromptsTokens prompts(&prompt, num_queries); const KVCaches kv_caches{&kv_cache, num_queries}; GenerateT(weights_u8, activations, runtime_config, prompts, pos, qbatch_start, kv_caches, pools, timing_info); } template void GenerateBatchT(const ByteStorageT& weights_u8, const RuntimeConfig& runtime_config, const MultiplePromptsTokens& prompts, size_t pos, const KVCaches& kv_caches, PerClusterPools& pools, TimingInfo& timing_info) { HWY_ASSERT(prompts.size() == kv_caches.size()); // Griffin does not support query batching. const size_t max_qbatch_size = (TConfig::kGriffinLayers > 0) ? 1 : runtime_config.decode_qbatch_size; Activations activations; activations.Allocate(max_qbatch_size); const size_t num_queries = prompts.size(); for (size_t qbatch_start = 0; qbatch_start < num_queries; qbatch_start += max_qbatch_size) { // Generate one batch of tokens from `qbatch_size` queries. const size_t qbatch_size = HWY_MIN(num_queries - qbatch_start, max_qbatch_size); const MultiplePromptsTokens qbatch_prompts(&prompts[qbatch_start], qbatch_size); const KVCaches qbatch_kv(&kv_caches[qbatch_start], qbatch_size); GenerateT(weights_u8, activations, runtime_config, qbatch_prompts, pos, qbatch_start, qbatch_kv, pools, timing_info); } } } // namespace HWY_NAMESPACE #if HWY_ONCE // These are extern functions defined by instantiations/*.cc, which include this // 'header' after defining GEMMA_CONFIG, which is for function overloading. void GenerateSingle( // NOLINT(misc-definitions-in-headers) GEMMA_CONFIG, const ByteStorageT& weights_u8, const RuntimeConfig& runtime_config, const PromptTokens& prompt, size_t pos, KVCache& kv_cache, PerClusterPools& pools, TimingInfo& timing_info) { HWY_EXPORT_AND_DYNAMIC_DISPATCH_T(GenerateSingleT) (weights_u8, runtime_config, prompt, pos, kv_cache, pools, timing_info); } void GenerateBatch( // NOLINT(misc-definitions-in-headers) GEMMA_CONFIG, const ByteStorageT& weights_u8, const RuntimeConfig& runtime_config, const MultiplePromptsTokens& prompts, size_t pos, const KVCaches& kv_caches, PerClusterPools& pools, TimingInfo& timing_info) { HWY_EXPORT_AND_DYNAMIC_DISPATCH_T(GenerateBatchT) (weights_u8, runtime_config, prompts, pos, kv_caches, pools, timing_info); } #endif // HWY_ONCE } // namespace gcpp HWY_AFTER_NAMESPACE(); #endif // THIRD_PARTY_GEMMA_CPP_GEMMA_GEMMA_INL_H_