From 41aee4df821854f37d90a45281f03b6db8d27de2 Mon Sep 17 00:00:00 2001 From: Kerfuffle <44031344+KerfuffleV2@users.noreply.github.com> Date: Fri, 27 Oct 2023 15:40:07 -0600 Subject: [PATCH] speculative : ensure draft and target model vocab matches (#3812) * speculative: Ensure draft and target model vocab matches * Tolerate small differences when checking dft vs tgt vocab --- examples/speculative/speculative.cpp | 33 +++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) diff --git a/examples/speculative/speculative.cpp b/examples/speculative/speculative.cpp index 92ad27e8e423c..f921b78455a72 100644 --- a/examples/speculative/speculative.cpp +++ b/examples/speculative/speculative.cpp @@ -8,6 +8,9 @@ #include #include +#define SPEC_VOCAB_MAX_SIZE_DIFFERENCE 100 +#define SPEC_VOCAB_CHECK_START_TOKEN_ID 5 + struct seq_draft { bool active = false; bool drafting = false; @@ -64,6 +67,33 @@ int main(int argc, char ** argv) { params.n_gpu_layers = params.n_gpu_layers_draft; std::tie(model_dft, ctx_dft) = llama_init_from_gpt_params(params); + { + const int n_vocab_tgt = llama_n_vocab(model_tgt); + const int n_vocab_dft = llama_n_vocab(model_dft); + const int vocab_diff = n_vocab_tgt > n_vocab_dft + ? n_vocab_tgt - n_vocab_dft + : n_vocab_dft - n_vocab_tgt; + + if (vocab_diff > SPEC_VOCAB_MAX_SIZE_DIFFERENCE) { + fprintf(stderr, "%s: error: draft model vocab must closely match target model to use speculation but ", __func__); + fprintf(stderr, "target vocab size %d does not match draft vocab size %d - difference %d, max allowed %d\n", + n_vocab_tgt, llama_n_vocab(model_dft), vocab_diff, SPEC_VOCAB_MAX_SIZE_DIFFERENCE); + return 1; + } + + for (int i = SPEC_VOCAB_CHECK_START_TOKEN_ID; i < std::min(n_vocab_tgt, n_vocab_dft); ++i) { + const char * token_text_tgt = llama_token_get_text(model_tgt, i); + const char * token_text_dft = llama_token_get_text(model_dft, i); + if (std::strcmp(token_text_tgt, token_text_dft) != 0) { + fprintf(stderr, "%s: error: draft model vocab must match target model to use speculation but ", __func__); + fprintf(stderr, "token %d content differs - target '%s', draft '%s'\n", i, + llama_token_to_piece(ctx_tgt, i).c_str(), + llama_token_to_piece(ctx_dft, i).c_str()); + return 1; + } + } + } + // tokenize the prompt std::vector inp; inp = ::llama_tokenize(ctx_tgt, params.prompt, true); @@ -227,6 +257,7 @@ int main(int argc, char ** argv) { llama_batch_add (batch_dft, id, n_past_dft, { 0 }, true); llama_kv_cache_seq_rm(ctx_dft, 0, n_past_dft, -1); + // LOG("dft batch: %s\n", LOG_BATCH_TOSTR_PRETTY(ctx_dft, batch_dft).c_str()); llama_decode (ctx_dft, batch_dft); ++n_past_dft; @@ -370,7 +401,7 @@ int main(int argc, char ** argv) { llama_kv_cache_seq_cp(ctx_tgt, 0, s, -1, -1); } - //LOG("target batch: %s\n", LOG_BATCH_TOSTR_PRETTY(ctx_tgt, batch_tgt)); + // LOG("target batch: %s\n", LOG_BATCH_TOSTR_PRETTY(ctx_tgt, batch_tgt).c_str()); llama_decode(ctx_tgt, batch_tgt); ++n_past_tgt; }