reshuffle blocks of code a bit

run.c

@@ -337,46 +337,6 @@ void transformer(int token, int pos, Config* p, RunState* s, TransformerWeights*
     matmul(s->logits, x, w->wcls, p->dim, p->vocab_size);
 }
 
-// https://en.wikipedia.org/wiki/Xorshift#xorshift.2A
-unsigned long long rng_seed;
-unsigned int random_u32() {
-    rng_seed ^= rng_seed >> 12;
-    rng_seed ^= rng_seed << 25;
-    rng_seed ^= rng_seed >> 27;
-    return (rng_seed * 0x2545F4914F6CDD1Dull) >> 32;
-}
-float random_f32() {
-    return (random_u32() >> 8) / 16777216.0f;
-}
-
-// ----------------------------------------------------------------------------
-// functions to sample the next token from the transformer's predicted distribution
-
-int sample(float* probabilities, int n) {
-    // sample index from probabilities, they must sum to 1
-    float r = random_f32();
-    float cdf = 0.0f;
-    for (int i = 0; i < n; i++) {
-        cdf += probabilities[i];
-        if (r < cdf) {
-            return i;
-        }
-    }
-    return n - 1; // in case of rounding errors
-}
-
-int argmax(float* v, int n) {
-    // return argmax of v in elements 0..n
-    int max_i = 0;
-    float max_p = v[0];
-    for (int i = 1; i < n; i++) {
-        if (v[i] > max_p) {
-            max_i = i;
-            max_p = v[i];
-        }
-    }
-    return max_i;
-}
 // ----------------------------------------------------------------------------
 // byte pair encoding (BPE) tokenizer, encodes strings into tokens so we can prompt
 
@@ -441,11 +401,51 @@ void bpe_encode(char *text, char **vocab, float *vocab_scores, int vocab_size, u
 
 // ----------------------------------------------------------------------------
 // utilities
+
 long time_in_ms() {
+    // return time in milliseconds, for benchmarking the model speed
     struct timespec time;
     clock_gettime(CLOCK_REALTIME, &time);
     return time.tv_sec * 1000 + time.tv_nsec / 1000000;
 }
+
+unsigned long long rng_seed;
+unsigned int random_u32() {
+    // xorshift rng: https://en.wikipedia.org/wiki/Xorshift#xorshift.2A
+    rng_seed ^= rng_seed >> 12;
+    rng_seed ^= rng_seed << 25;
+    rng_seed ^= rng_seed >> 27;
+    return (rng_seed * 0x2545F4914F6CDD1Dull) >> 32;
+}
+float random_f32() { // random float32 in [0,1)
+    return (random_u32() >> 8) / 16777216.0f;
+}
+
+int sample(float* probabilities, int n) {
+    // sample index from probabilities, they must sum to 1
+    float r = random_f32();
+    float cdf = 0.0f;
+    for (int i = 0; i < n; i++) {
+        cdf += probabilities[i];
+        if (r < cdf) {
+            return i;
+        }
+    }
+    return n - 1; // in case of rounding errors
+}
+
+int argmax(float* v, int n) {
+    // return argmax of v in elements 0..n
+    int max_i = 0;
+    float max_p = v[0];
+    for (int i = 1; i < n; i++) {
+        if (v[i] > max_p) {
+            max_i = i;
+            max_p = v[i];
+        }
+    }
+    return max_i;
+}
 // ----------------------------------------------------------------------------
 
 int main(int argc, char *argv[]) {