git push origin masterMerge branch 'admu-progvar-master'

This commit is contained in:
Andrej Karpathy
2023-07-24 20:39:40 +00:00
+8 -5
View File
@@ -60,7 +60,7 @@ typedef struct {
float *q; // query (dim,)
float *k; // key (dim,)
float *v; // value (dim,)
float *att; // buffer for scores/attention values (seq_len,)
float *att; // buffer for scores/attention values (n_heads, seq_len)
float *logits; // output logits
// kv cache
float* key_cache; // (layer, seq_len, dim)
@@ -77,7 +77,7 @@ void malloc_run_state(RunState* s, Config* p) {
s->q = calloc(p->dim, sizeof(float));
s->k = calloc(p->dim, sizeof(float));
s->v = calloc(p->dim, sizeof(float));
s->att = calloc(p->seq_len, sizeof(float));
s->att = calloc(p->n_heads * p->seq_len, sizeof(float));
s->logits = calloc(p->vocab_size, sizeof(float));
s->key_cache = calloc(p->n_layers * p->seq_len * p->dim, sizeof(float));
s->value_cache = calloc(p->n_layers * p->seq_len * p->dim, sizeof(float));
@@ -278,9 +278,12 @@ void transformer(int token, int pos, Config* p, RunState* s, TransformerWeights*
memcpy(value_cache_row, s->v, dim*sizeof(*value_cache_row));
// multihead attention. iterate over all heads
#pragma omp parallel for
for (int h = 0; h < p->n_heads; h++) {
// get the query vector for this head
float* q = s->q + h * head_size;
// attention scores for this head
float* att = s->att + h * p->seq_len;
// iterate over all timesteps, including the current one
for (int t = 0; t <= pos; t++) {
// get the key vector for this head and at this timestep
@@ -292,17 +295,17 @@ void transformer(int token, int pos, Config* p, RunState* s, TransformerWeights*
}
score /= sqrtf(head_size);
// save the score to the attention buffer
s->att[t] = score;
att[t] = score;
}
// softmax the scores to get attention weights, from 0..pos inclusively
softmax(s->att, pos + 1);
softmax(att, pos + 1);
// weighted sum of the values, store back into xb
for (int i = 0; i < head_size; i++) {
float val = 0.0f;
for (int t = 0; t <= pos; t++) {
val += s->att[t] * s->value_cache[loff + t * dim + h * head_size + i]; // note bad locality
val += att[t] * s->value_cache[loff + t * dim + h * head_size + i]; // note bad locality
}
s->xb[h * head_size + i] = val;
}