clean up swiglu a little bit

run.c

@@ -339,14 +339,14 @@ float* forward(Transformer* transformer, int token, int pos) {
         matmul(s->hb, s->xb, w->w1 + l*dim*hidden_dim, dim, hidden_dim);
         matmul(s->hb2, s->xb, w->w3 + l*dim*hidden_dim, dim, hidden_dim);
 
-        // F.silu; silu(x)=x*σ(x),where σ(x) is the logistic sigmoid
+        // SwiGLU non-linearity
         for (int i = 0; i < hidden_dim; i++) {
-            s->hb[i] = s->hb[i] * (1.0f / (1.0f + expf(-s->hb[i])));
-        }
-
-        // elementwise multiply with w3(x)
-        for (int i = 0; i < hidden_dim; i++) {
-            s->hb[i] = s->hb[i] * s->hb2[i];
+            float val = s->hb[i];
+            // silu(x)=x*σ(x), where σ(x) is the logistic sigmoid
+            val *= (1.0f / (1.0f + expf(-val)));
+            // elementwise multiply with w3(x)
+            val *= s->hb2[i];
+            s->hb[i] = val;
         }
 
         // final matmul to get the output of the ffn