make top_p_sampling supports threshold (#55486)

* make top_p_sampling supports threshold

* delete __nv_bfloat16

paddle/phi/api/yaml/ops.yaml

@@ -1922,13 +1922,14 @@
   backward : thresholded_relu_grad
 
 - op : top_p_sampling
-  args : (Tensor x, Tensor ps, int random_seed=-1)
+  args : (Tensor x, Tensor ps, Tensor threshold, int random_seed=-1)
   output : Tensor (out), Tensor(ids)
   infer_meta :
     func : TopPSamplingInferMeta
   kernel :
     func : top_p_sampling
     data_type : x
+  optional : threshold
 
 - op : topk
   args : (Tensor x, Scalar(int) k = 1, int axis = -1, bool largest = true, bool sorted = true)

paddle/phi/infermeta/binary.cc

@@ -2744,6 +2744,7 @@ void TriangularSolveInferMeta(const MetaTensor& x,
 
 void TopPSamplingInferMeta(const MetaTensor& x,
                            const MetaTensor& ps,
+                           const MetaTensor& threshold,
                            int random_seed,
                            MetaTensor* out,
                            MetaTensor* ids) {

paddle/phi/infermeta/binary.h

@@ -430,6 +430,7 @@ void TriangularSolveInferMeta(const MetaTensor& x,
 
 void TopPSamplingInferMeta(const MetaTensor& x,
                            const MetaTensor& ps,
+                           const MetaTensor& threshold,
                            int random_seed,
                            MetaTensor* out,
                            MetaTensor* ids);

paddle/phi/kernels/gpu/top_p_sampling_kernel.cu

@@ -41,11 +41,6 @@ struct DataTypeTraits<phi::dtype::float16> {
   using DataType = half;
 };
 
-// template <>
-// struct DataTypeTraits<phi::dtype::bfloat16> {
-//   using DataType = __nv_bfloat16;
-// };
-
 #define FINAL_MASK 0xFFFFFFFF
 
 #define FIXED_BLOCK_DIM_BASE(dim, ...) \
@@ -119,7 +114,7 @@ __global__ void setup_kernel(curandState_t* state,
                              const int bs) {
   int idx = blockIdx.x * blockDim.x + threadIdx.x;
   for (int i = idx; i < bs; i += gridDim.x * blockDim.x) {
-    curand_init(seed + i, 0, 0, &state[i]);
+    curand_init(seed, i, 0, &state[i]);
   }
 }
 
@@ -278,6 +273,7 @@ __device__ __forceinline__ void BlockReduce(Pair<T> shared_max[],
 
 template <typename T, int MaxLength, int TopPBeamTopK, int BlockSize>
 __global__ void KeMatrixTopPBeamTopK(const T* src,
+                                     const T* threshold,
                                      T* top_ps,
                                      int64_t* out_id,  // topk id
                                      T* out_val,       // topk val
@@ -289,6 +285,8 @@ __global__ void KeMatrixTopPBeamTopK(const T* src,
   const int wid = tid / 32;
   const int lane = tid % 32;
   const int bid = blockIdx.x;
+  const float threshold_now =
+      threshold ? static_cast<float>(threshold[bid]) : 0.f;
 
   int top_num = TopPBeamTopK;
   float top_p_num = static_cast<float>(top_ps[bid]);
@@ -329,8 +327,10 @@ __global__ void KeMatrixTopPBeamTopK(const T* src,
     float rand_top_p = curand_uniform(state + bid) * top_p_num;
     top_ps[bid] = (T)rand_top_p;
     float sum_prob = 0.0f;
+
     for (int i = 0; i < TopPBeamTopK; i++) {
-      sum_prob += static_cast<float>(beam_max[i].v);
+      float val = static_cast<float>(beam_max[i].v);
+      sum_prob += val;
 #ifdef DEBUG_TOPP
       printf("bi: %d, top_p: %f, rand_top_p: %f, sum_prob: %f\n",
              bid,
@@ -340,12 +340,21 @@ __global__ void KeMatrixTopPBeamTopK(const T* src,
 #endif
       if (sum_prob >= rand_top_p) {
         count_iter_begin[bid] += 1;
-        out_id[bid] = (int64_t)beam_max[i].id;
+        if (val < threshold_now) {
+          // don't sample low score token
+          int start_id = i == 0 ? 0 : i - 1;
+          for (int j = start_id; j >= 0; j--) {
+            float val_now = static_cast<float>(beam_max[j].v);
+            if (val_now >= threshold_now || j == 0) {
+              out_id[bid] = static_cast<int64_t>(beam_max[j].id);
+              out_val[bid] = beam_max[j].v;
+              break;
+            }
+          }
+        } else {
+          out_id[bid] = static_cast<int64_t>(beam_max[i].id);
           out_val[bid] = beam_max[i].v;
-#ifdef DEBUG_TOPP
-        printf(
-            "bi: %d, early stop id: %d\n", bid, static_cast<int>(out_id[bid]));
-#endif
+        }
         break;
       }
     }
@@ -374,11 +383,14 @@ __global__ void FillIndex(T* indices, T num_rows, T num_cols) {
 }
 
 struct BlockPrefixCallbackOp {
+  // Running prefix
   float running_total;
-
+  // Constructor
   __device__ BlockPrefixCallbackOp(float running_total)
       : running_total(running_total) {}
-
+  // Callback operator to be entered by the first warp of threads in the block.
+  // Thread-0 is responsible for returning a value for seeding the block-wide
+  // scan.
   __device__ float operator()(float block_aggregate) {
     float old_prefix = running_total;
     running_total += block_aggregate;
@@ -386,14 +398,28 @@ struct BlockPrefixCallbackOp {
   }
 };
 
+template <typename T>
+__device__ T max_func(const T a, const T b) {
+  return a > b ? a : b;
+}
+
+template <typename T>
+struct MaxOp {
+  __device__ __forceinline__ T operator()(const T& a, const T& b) const {
+    return max_func(a, b);
+  }
+};
+
 template <typename T, int BLOCK_SIZE>
 __global__ void topp_sampling(T* sorted_probs,
                               int64_t* sorted_id,
                               T* out_val,
                               int64_t* out_id,
                               const T* top_ps,
-                              int p_num,
-                              int vocab_size,
+                              const T* threshold,
+                              const uint64_t seed,
+                              const int p_num,
+                              const int vocab_size,
                               int* count_iter,
                               int* count_iter_begin) {
   __shared__ int stop_shared;
@@ -404,6 +430,8 @@ __global__ void topp_sampling(T* sorted_probs,
   const int lane_id = tid % 32;
   const int warp_id = tid / 32;
   const float p_t = static_cast<float>(top_ps[bid]);
+  const float threshold_now =
+      threshold ? static_cast<float>(threshold[bid]) : 0.f;
   if (tid == 0) {
     stop_shared = 0;
     rand_p = p_t;
@@ -417,8 +445,11 @@ __global__ void topp_sampling(T* sorted_probs,
   }
 
   typedef cub::BlockScan<float, BLOCK_SIZE> BlockScan;
+  typedef cub::BlockReduce<int, BLOCK_SIZE> BlockReduce;
   __shared__ typename BlockScan::TempStorage temp_storage;
+  __shared__ typename BlockReduce::TempStorage temp_storage_reduce;
   __shared__ uint32_t selected_shared[NUM_WARPS];
+  int threshold_id = 0;
 
   // Initialize running total
   BlockPrefixCallbackOp prefix_op(0);
@@ -429,23 +460,15 @@ __global__ void topp_sampling(T* sorted_probs,
   __syncthreads();
 
   int offset = bid * vocab_size;
-#ifdef DEBUG_TOPP
-  if (tid == 0) {
-    printf(
-        "first_elem1_1: %f, first_elem1_2: %f, first_id1_1: %d, first_id1_2: "
-        "%d\n",
-        static_cast<float>(sorted_probs[offset]),
-        static_cast<float>(sorted_probs[offset + 1]),
-        static_cast<int>(sorted_id[offset]),
-        static_cast<int>(sorted_id[offset + 1]);
-  }
-#endif
   int end = ((vocab_size + BLOCK_SIZE - 1) / BLOCK_SIZE) * BLOCK_SIZE;
   int i_activate = 0;
   float thread_offset = 0;
   for (int i = tid; i < end; i += BLOCK_SIZE) {
     float thread_count =
         (i < vocab_size) ? static_cast<float>(sorted_probs[offset + i]) : 0.f;
+    if (i < vocab_size && thread_count >= threshold_now) {
+      threshold_id = i;
+    }
     BlockScan(temp_storage)
         .InclusiveSum(thread_count, thread_offset, prefix_op);
 
@@ -466,32 +489,15 @@ __global__ void topp_sampling(T* sorted_probs,
   __syncthreads();
   if (stop_shared == 0) {
     if (tid == 0) {
-      out_id[bid] = sorted_id[offset + vocab_size - 1];
-      out_val[bid] = sorted_probs[offset + vocab_size - 1];
-#ifdef DEBUG_TOPP
-      printf("stop_shared: %d, out_id: %d, out_val: %f\n",
-             static_cast<int>(stop_shared),
-             static_cast<int>(out_id[bid]),
-             static_cast<float>(out_val[bid]);
-#endif
+      out_id[bid] = sorted_id[offset];
+      out_val[bid] = sorted_probs[offset];
     }
     return;
   }
-
-#ifdef DEBUG_TOPP
-  if (tid == 0) {
-    printf(
-        "first_elem2_1: %f, first_elem2_2: %f, first_id2_1: %d, first_id2_2: "
-        "%d\n",
-        static_cast<float>(sorted_probs[offset]),
-        static_cast<float>(sorted_probs[offset + 1]),
-        static_cast<int>(sorted_id[offset]),
-        static_cast<int>(sorted_id[offset + 1]);
-  }
-#endif
   bool skip = (selected_shared[warp_id] > 0) ? false : true;
   for (int i = 0; i < warp_id; i++) {
     if (selected_shared[i] != 0) {
+      // If the previous has stopped, skip the current warp
       skip = true;
     }
   }
@@ -499,19 +505,22 @@ __global__ void topp_sampling(T* sorted_probs,
     int active_lane_id =
         WARP_SIZE - __popc(selected_shared[warp_id]);  // first not 0
     if (lane_id == active_lane_id) {
-#ifdef DEBUG_TOPP
-      printf(
-          "active_lane_id: %d, i_activate: %d.\n", active_lane_id, i_activate);
-      for (int i = 0; i < active_lane_id; i++) {
-        printf("p %d, value: %f\n",
-               i,
-               static_cast<float>(sorted_probs[offset + i]));
-      }
-#endif
+      float val = static_cast<float>(sorted_probs[offset + i_activate]);
+      if (val < threshold_now) {
+        // don't sample low score token
+        int max_id =
+            BlockReduce(temp_storage_reduce).Reduce(threshold_id, MaxOp<int>());
+        curandStatePhilox4_32_10_t rng;
+        curand_init(seed, tid, 0, &rng);
+        int random_id = curand(&rng) % (max_id + 1);
+        out_id[bid] = sorted_id[offset + random_id];
+        out_val[bid] = sorted_probs[offset + random_id];
+      } else {
         out_id[bid] = sorted_id[offset + i_activate];
         out_val[bid] = sorted_probs[offset + i_activate];
       }
     }
+  }
 }
 
 int GetBlockSize(int vocab_size) {
@@ -544,10 +553,26 @@ __global__ void print_kernel(T* input, int size) {
   }
 }
 
+template <typename T>
+T* SafeGetTensorPtr(const DenseTensor& t) {
+  return const_cast<T*>(t.data<T>());
+}
+
+template <typename T>
+T* SafeGetTensorPtr(const DenseTensor* t) {
+  return t ? SafeGetTensorPtr<T>(*t) : nullptr;
+}
+
+template <typename T>
+T* SafeGetTensorPtr(const paddle::optional<DenseTensor>& t) {
+  return t ? SafeGetTensorPtr<T>(t.get()) : nullptr;
+}
+
 template <typename T, typename Context>
 void TopPSamplingKernel(const Context& dev_ctx,
                         const DenseTensor& x,
                         const DenseTensor& ps,
+                        const paddle::optional<DenseTensor>& threshold,
                         int random_seed,
                         DenseTensor* out,
                         DenseTensor* ids) {
@@ -597,11 +622,12 @@ void TopPSamplingKernel(const Context& dev_ctx,
       phi::Stream(reinterpret_cast<phi::StreamId>(dev_ctx.stream())));
   dev_curand_states =
       reinterpret_cast<curandState_t*>(curand_states_buf->ptr());
+  unsigned int seed = 0;
   if (random_seed == -1) {
-    srand((unsigned int)(time(NULL)));
-    setup_kernel<<<1, 256, 0, cu_stream>>>(dev_curand_states, rand(), bs);
+    rand_r(&seed);
+    setup_kernel<<<1, 256, 0, cu_stream>>>(dev_curand_states, seed, bs);
   } else {
-    setup_kernel<<<1, 256, 0, cu_stream>>>(dev_curand_states, random_seed, bs);
+    seed = random_seed;
   }
 
   DenseTensor count_iter;
@@ -612,12 +638,15 @@ void TopPSamplingKernel(const Context& dev_ctx,
   dev_ctx.template Alloc<int>(&count_iter_begin);
   SetCountIter<<<1, 256, 0, cu_stream>>>(count_iter.data<int>(), bs + 1);
 
+  T* threshold_data = SafeGetTensorPtr<T>(threshold);
+
   constexpr int TopKMaxLength = 2;
   constexpr int TopPBeamTopK = 10;
   switch (BlockSize) {
     FIXED_BLOCK_DIM(
         KeMatrixTopPBeamTopK<T, TopKMaxLength, TopPBeamTopK, kBlockDim>
         <<<bs, kBlockDim, 0, cu_stream>>>(x.data<T>(),
+                                          threshold_data,
                                           ps_now.data<T>(),
                                           ids_ptr,
                                           out_ptr,
@@ -682,6 +711,8 @@ void TopPSamplingKernel(const Context& dev_ctx,
                                           out_ptr,
                                           ids_ptr,
                                           ps_now.data<T>(),
+                                          threshold_data,
+                                          seed,
                                           p_num,
                                           vocab_size,
                                           count_iter.data<int>(),

paddle/phi/kernels/top_p_sampling_kernel.h

@@ -22,6 +22,7 @@ template <typename T, typename Context>
 void TopPSamplingKernel(const Context& dev_ctx,
                         const DenseTensor& x,
                         const DenseTensor& ps,
+                        const paddle::optional<DenseTensor>& threshold,
                         int random_seed,
                         DenseTensor* out,
                         DenseTensor* ids);

python/paddle/fluid/tests/unittests/test_top_p_sampling.py

@@ -53,6 +53,9 @@ def TopPProcess(probs, top_p):
     return next_scores, next_tokens
 
 
+@unittest.skipIf(
+    not core.is_compiled_with_cuda(), "core is not compiled with CUDA "
+)
 class TestTopPAPI(unittest.TestCase):
     def setUp(self):
         self.topp = 0.0
@@ -74,7 +77,7 @@ class TestTopPAPI(unittest.TestCase):
             ).reshape((-1, 1))
             # test case for basic test case 1
             paddle_result = paddle.top_p_sampling(
-                input_tensor, topp_tensor, self.seed
+                input_tensor, topp_tensor, seed=self.seed
             )
             ref_res = TopPProcess(input_tensor, self.topp)
 
@@ -98,7 +101,9 @@ class TestTopPAPI(unittest.TestCase):
             topp_tensor = paddle.static.data(
                 name="topp", shape=[6, 1], dtype=self.dtype
             )
-            result = paddle.top_p_sampling(input_tensor, topp_tensor, self.seed)
+            result = paddle.top_p_sampling(
+                input_tensor, topp_tensor, seed=self.seed
+            )
             ref_res = TopPProcess(input_tensor, self.topp)
             exe = paddle.static.Executor(place)
             input_data = np.random.rand(6, 1030).astype(self.dtype)

python/paddle/tensor/search.py

@@ -1131,13 +1131,14 @@ def kthvalue(x, k, axis=None, keepdim=False, name=None):
     return values, indices
 
 
-def top_p_sampling(x, ps, seed=None, name=None):
+def top_p_sampling(x, ps, threshold=None, seed=None, name=None):
     """
     Get the TopP scores and ids.
 
     Args:
         x(Tensor): A N-D Tensor with type float32, float16 and bfloat16.
         ps(Tensor): A 1-D Tensor with type float32, float16 and bfloat16.
+        threshold(Tensor): A 1-D Tensor with type float32, float16 and bfloat16.
         seed(int, optional): the random seed,
         name (str, optional): For details, please refer to :ref:`api_guide_Name`. Generally, no setting is required. Default: None.
 
@@ -1149,10 +1150,10 @@ def top_p_sampling(x, ps, seed=None, name=None):
         seed = -1
 
     if in_dygraph_mode():
-        return _C_ops.top_p_sampling(x, ps, seed)
+        return _C_ops.top_p_sampling(x, ps, threshold, seed)
 
-    inputs = {"x": [x], "ps": [ps]}
-    attrs = {"seed": seed}
+    inputs = {"x": x, "ps": ps, "threshold": threshold}
+    attrs = {"random_seed": seed}
 
     helper = LayerHelper('top_p_sampling', **locals())
     out = helper.create_variable_for_type_inference(dtype=x.dtype)
@@ -1160,7 +1161,7 @@ def top_p_sampling(x, ps, seed=None, name=None):
     helper.append_op(
         type='top_p_sampling',
         inputs=inputs,
-        outputs={'out': [out], 'ids': [ids]},
+        outputs={'out': out, 'ids': ids},
         attrs=attrs,
     )
     return out, ids