fix commented-out kernel variants

Author: JohannesGaessler

ggml-cuda/fattn-vec-f16.cu

@@ -382,37 +382,38 @@ void launch_fattn_vec_f16_64_128(ggml_backend_cuda_context & ctx, ggml_tensor *
 
 void ggml_cuda_flash_attn_ext_vec_f16_no_mma(ggml_backend_cuda_context & ctx, ggml_tensor * dst) {
     const ggml_tensor * KQV = dst;
+    const ggml_tensor * Q   = dst->src[0];
 
     const int32_t precision = KQV->op_params[2];
     GGML_ASSERT(precision == GGML_PREC_DEFAULT);
 
-    // if (Q->ne[1] == 1) {
-    //     constexpr int cols_per_block  = 1;
-    //     constexpr int parallel_blocks = 4;
-    //     launch_fattn_vec_f16_64_128<cols_per_block, parallel_blocks>(ctx, dst);
-    //     return;
-    // }
-
-    // if (Q->ne[1] == 2) {
-    //     constexpr int cols_per_block  = 2;
-    //     constexpr int parallel_blocks = 4;
-    //     launch_fattn_vec_f16_64_128<cols_per_block, parallel_blocks>(ctx, dst);
-    //     return;
-    // }
-
-    // if (Q->ne[1] <= 4) {
-    //     constexpr int cols_per_block  = 4;
-    //     constexpr int parallel_blocks = 4;
-    //     launch_fattn_vec_f16_64_128<cols_per_block, parallel_blocks>(ctx, dst);
-    //     return;
-    // }
-
-    // if (Q->ne[1] <= 8) {
-    //     constexpr int cols_per_block  = 8;
-    //     constexpr int parallel_blocks = 4;
-    //     launch_fattn_vec_f16_64_128<cols_per_block, parallel_blocks>(ctx, dst);
-    //     return;
-    // }
+    if (Q->ne[1] == 1) {
+        constexpr int cols_per_block  = 1;
+        constexpr int parallel_blocks = 4;
+        launch_fattn_vec_f16_64_128<cols_per_block, parallel_blocks>(ctx, dst);
+        return;
+    }
+
+    if (Q->ne[1] == 2) {
+        constexpr int cols_per_block  = 2;
+        constexpr int parallel_blocks = 4;
+        launch_fattn_vec_f16_64_128<cols_per_block, parallel_blocks>(ctx, dst);
+        return;
+    }
+
+    if (Q->ne[1] <= 4) {
+        constexpr int cols_per_block  = 4;
+        constexpr int parallel_blocks = 4;
+        launch_fattn_vec_f16_64_128<cols_per_block, parallel_blocks>(ctx, dst);
+        return;
+    }
+
+    if (Q->ne[1] <= 8) {
+        constexpr int cols_per_block  = 8;
+        constexpr int parallel_blocks = 4;
+        launch_fattn_vec_f16_64_128<cols_per_block, parallel_blocks>(ctx, dst);
+        return;
+    }
 
     constexpr int cols_per_block  = 8;
     constexpr int parallel_blocks = 1;