Addressing review comments

This commit is contained in:
Sami 2019-09-09 13:54:46 -07:00
parent e882f17498
commit 736eba374e
2 changed files with 204 additions and 332 deletions

View File

@ -15,6 +15,7 @@ limitations under the License.
#if GOOGLE_CUDA
#define EIGEN_USE_GPU
#include <limits>
#include "absl/strings/str_cat.h"
#include "tensorflow/core/framework/numeric_types.h"
#include "tensorflow/core/framework/op_kernel.h"
@ -80,19 +81,8 @@ __device__ EIGEN_STRONG_INLINE void Swap(T& a, T& b) {
b = c;
}
template <bool T>
__device__ float legacy_offset(float);
template <>
__device__ EIGEN_STRONG_INLINE float legacy_offset<true>(float a) {
return a + 1.0;
}
template <>
__device__ EIGEN_STRONG_INLINE float legacy_offset<false>(float a) {
return a;
}
// Check whether two boxes have an IoU greater than threshold.
template <typename T, bool L>
template <typename T>
__device__ EIGEN_STRONG_INLINE bool OverThreshold(const Box* a, const Box* b,
const float a_area,
const T iou_threshold) {
@ -104,8 +94,8 @@ __device__ EIGEN_STRONG_INLINE bool OverThreshold(const Box* a, const Box* b,
const float yy2 = fminf(a->y2, b->y2);
// fdimf computes the positive difference between xx2+1 and xx1.
const float w = fdimf(legacy_offset<L>(xx2), xx1);
const float h = fdimf(legacy_offset<L>(yy2), yy1);
const float w = fdimf(xx2, xx1);
const float h = fdimf(yy2, yy1);
const float intersection = w * h;
// Testing for aa/bb > t
@ -130,10 +120,10 @@ __device__ EIGEN_STRONG_INLINE void Flipped<true>(Box& box) {
}
template <typename T>
__device__ EIGEN_STRONG_INLINE bool CheckBit(T* bit_mask, int bit) {
constexpr int SHIFTLEN = NumBits(8 * sizeof(T)) - 1;
constexpr int REMAINDER_MASK = 8 * sizeof(T) - 1;
int bin = bit >> SHIFTLEN;
return (bit_mask[bin] >> (bit & REMAINDER_MASK)) & 1;
constexpr int kShiftLen = NumBits(8 * sizeof(T)) - 1;
constexpr int kRemainderMask = 8 * sizeof(T) - 1;
int bin = bit >> kShiftLen;
return (bit_mask[bin] >> (bit & kRemainderMask)) & 1;
}
// Produce a global bitmask (result_mask) of selected boxes from bitmask
@ -180,11 +170,11 @@ __global__ void NMSReduce(const int* bitmask, const int bit_mask_len,
// If flip_box is true boxes may have x1>x2 and or y1>y2. If so change the
// coordinates such that for all boxes x1<x2 and y1<y2. Else boxes should have
// x1<x2 and y1<y2.
template <bool flip_box, bool legacy_mode>
template <bool flip_box>
__launch_bounds__(kNmsBlockDim* kNmsBlockDim, 4) __global__
void NMSKernel(const Box* d_desc_sorted_boxes,
const int num_boxes, const float iou_threshold,
const int bit_mask_len, int* d_delete_mask) {
void NMSKernel(const Box* d_desc_sorted_boxes, const int num_boxes,
const float iou_threshold, const int bit_mask_len,
int* d_delete_mask) {
// Storing boxes used by this CUDA block in the shared memory.
__shared__ Box shared_i_boxes[kNmsBlockDim];
// Same thing with areas
@ -224,8 +214,8 @@ __launch_bounds__(kNmsBlockDim* kNmsBlockDim, 4) __global__
Box j_box = d_desc_sorted_boxes[j];
const Box i_box = shared_i_boxes[threadIdx.x];
Flipped<flip_box>(j_box);
if (OverThreshold<float, legacy_mode>(
&i_box, &j_box, shared_i_areas[threadIdx.x], iou_threshold)) {
if (OverThreshold<float>(&i_box, &j_box, shared_i_areas[threadIdx.x],
iou_threshold)) {
// we have score[j] <= score[i].
above_threshold |= (1U << ib);
}
@ -247,8 +237,7 @@ __device__ EIGEN_STRONG_INLINE void SelectHelper(const Index i_selected,
template <typename Index, typename T, typename... Args>
__device__ EIGEN_STRONG_INLINE void SelectHelper(const Index i_selected,
const Index i_original,
const T* original,
T* selected,
const T* original, T* selected,
Args... args) {
selected[i_selected] = original[i_original];
SelectHelper(i_selected, i_original, args...);
@ -261,18 +250,15 @@ __device__ EIGEN_STRONG_INLINE void SelectHelper(const Index i_selected,
// IndexMultiSelect(num_elements, indices, original1 ,selected1, original2,
// selected2).
template <typename Index, typename T, typename... Args>
__global__ void IndexMultiSelect(const int num_elements,
const Index* indices,
const T* original,
T* selected, Args... args) {
__global__ void IndexMultiSelect(const int num_elements, const Index* indices,
const T* original, T* selected, Args... args) {
for (const int idx : CudaGridRangeX(num_elements)) {
SelectHelper(idx, indices[idx], original, selected, args...);
}
}
template <typename T>
__global__ void Iota(const int num_elements, const T offset,
T* to_fill) {
__global__ void Iota(const int num_elements, const T offset, T* to_fill) {
for (int idx : CudaGridRangeX(num_elements)) {
to_fill[idx] = static_cast<T>(idx) + offset;
}
@ -280,8 +266,7 @@ __global__ void Iota(const int num_elements, const T offset,
Status NmsGpu(const float* d_sorted_boxes_float_ptr, const int num_boxes,
const float iou_threshold, int* d_selected_indices, int* h_nkeep,
OpKernelContext* context, const int max_boxes, bool flip_boxes,
bool legacy_mode) {
OpKernelContext* context, const int max_boxes, bool flip_boxes) {
// Making sure we respect the __align(16)__
// we promised to the compiler.
auto iptr = reinterpret_cast<std::uintptr_t>(d_sorted_boxes_float_ptr);
@ -309,9 +294,8 @@ Status NmsGpu(const float* d_sorted_boxes_float_ptr, const int num_boxes,
alloc_attr.set_gpu_compatible(true);
// Size of this buffer can be reduced to kNmsChunkSize*bit_mask_len*2 and
// using it as a ring buffer. However savings should be a few MB .
TF_RETURN_IF_ERROR(context->allocate_temp(DataType::DT_INT32,
TensorShape({1}),
&h_num_selected, alloc_attr));
TF_RETURN_IF_ERROR(context->allocate_temp(
DataType::DT_INT32, TensorShape({1}), &h_num_selected, alloc_attr));
int* d_delete_mask = d_nms_mask.flat<int>().data();
int* h_selected_count = h_num_selected.flat<int>().data();
@ -327,29 +311,13 @@ Status NmsGpu(const float* d_sorted_boxes_float_ptr, const int num_boxes,
thread_block.y = kNmsBlockDim;
thread_block.z = 1;
if (flip_boxes) {
if (!legacy_mode) {
TF_CHECK_OK(GpuLaunchKernel(NMSKernel<true, false>, block_dim,
thread_block, 0, device.stream(),
d_sorted_boxes, num_boxes, iou_threshold,
bit_mask_len, d_delete_mask));
} else {
TF_CHECK_OK(GpuLaunchKernel(NMSKernel<true, true>, block_dim,
thread_block, 0, device.stream(),
d_sorted_boxes, num_boxes, iou_threshold,
bit_mask_len, d_delete_mask));
}
TF_CHECK_OK(GpuLaunchKernel(NMSKernel<true>, block_dim, thread_block, 0,
device.stream(), d_sorted_boxes, num_boxes,
iou_threshold, bit_mask_len, d_delete_mask));
} else {
if (!legacy_mode) {
TF_CHECK_OK(GpuLaunchKernel(NMSKernel<false, false>, block_dim,
thread_block, 0, device.stream(),
d_sorted_boxes, num_boxes, iou_threshold,
bit_mask_len, d_delete_mask));
} else {
TF_CHECK_OK(GpuLaunchKernel(NMSKernel<false, true>, block_dim,
thread_block, 0, device.stream(),
d_sorted_boxes, num_boxes, iou_threshold,
bit_mask_len, d_delete_mask));
}
TF_CHECK_OK(GpuLaunchKernel(NMSKernel<false>, block_dim, thread_block, 0,
device.stream(), d_sorted_boxes, num_boxes,
iou_threshold, bit_mask_len, d_delete_mask));
}
TF_RETURN_IF_CUDA_ERROR(cudaGetLastError());
// Overlapping CPU computes and D2H memcpy
@ -408,152 +376,6 @@ Status NmsGpu(const float* d_sorted_boxes_float_ptr, const int num_boxes,
return Status::OK();
}
class NonMaxSuppressionV2GPUOp : public OpKernel {
public:
explicit NonMaxSuppressionV2GPUOp(OpKernelConstruction* context)
: OpKernel(context) {}
void Compute(OpKernelContext* context) override {
// boxes: [num_boxes, 4]
const Tensor& boxes = context->input(0);
// scores: [num_boxes]
const Tensor& scores = context->input(1);
// max_output_size: scalar
const Tensor& max_output_size = context->input(2);
OP_REQUIRES(
context, TensorShapeUtils::IsScalar(max_output_size.shape()),
errors::InvalidArgument("max_output_size must be 0-D, got shape ",
max_output_size.shape().DebugString()));
// iou_threshold: scalar
const Tensor& iou_threshold = context->input(3);
OP_REQUIRES(context, TensorShapeUtils::IsScalar(iou_threshold.shape()),
errors::InvalidArgument("iou_threshold must be 0-D, got shape ",
iou_threshold.shape().DebugString()));
const float iou_threshold_val = iou_threshold.scalar<float>()();
OP_REQUIRES(context, iou_threshold_val >= 0 && iou_threshold_val <= 1,
errors::InvalidArgument("iou_threshold must be in [0, 1]"));
OP_REQUIRES(context, boxes.dims() == 2,
errors::InvalidArgument("boxes must be a rank 2 tensor!"));
int num_boxes = boxes.dim_size(0);
OP_REQUIRES(context, boxes.dim_size(1) == 4,
errors::InvalidArgument("boxes must be Nx4"));
OP_REQUIRES(context, scores.dims() == 1,
errors::InvalidArgument("scores must be a vector!"));
OP_REQUIRES(
context, scores.dim_size(0) == num_boxes,
errors::InvalidArgument(
"scores has incompatible shape")); // message must be exactly this
// otherwise tests fail!
if (num_boxes == 0) {
Tensor* output_indices = nullptr;
OP_REQUIRES_OK(context, context->allocate_output(0, TensorShape({0}),
&output_indices));
return;
}
const int output_size = max_output_size.scalar<int>()();
size_t cub_sort_temp_storage_bytes = 0;
auto cuda_stream = GetGpuStream(context);
auto device = context->eigen_gpu_device();
// Calling cub with nullptrs as inputs will make it return
// workspace size needed for the operation instead of doing the operation.
// In this specific instance, cub_sort_temp_storage_bytes will contain the
// necessary workspace size for sorting after the call.
cudaError_t cuda_ret = cub::DeviceRadixSort::SortPairsDescending(
nullptr, cub_sort_temp_storage_bytes,
static_cast<float*>(nullptr), // scores
static_cast<float*>(nullptr), // sorted scores
static_cast<int*>(nullptr), // input indices
static_cast<int*>(nullptr), // sorted indices
num_boxes, // num items
0, 8 * sizeof(float), // sort all bits
cuda_stream);
TF_OP_REQUIRES_CUDA_SUCCESS(context, cuda_ret);
Tensor d_cub_sort_buffer;
OP_REQUIRES_OK(context,
context->allocate_temp(
DataType::DT_INT8,
TensorShape({(int64)cub_sort_temp_storage_bytes}),
&d_cub_sort_buffer));
Tensor d_indices;
OP_REQUIRES_OK(
context, context->allocate_temp(DataType::DT_INT32,
TensorShape({num_boxes}), &d_indices));
Tensor d_sorted_indices;
OP_REQUIRES_OK(context, context->allocate_temp(DataType::DT_INT32,
TensorShape({num_boxes}),
&d_sorted_indices));
Tensor d_selected_indices;
OP_REQUIRES_OK(context, context->allocate_temp(DataType::DT_INT32,
TensorShape({num_boxes}),
&d_selected_indices));
Tensor d_sorted_scores;
OP_REQUIRES_OK(context, context->allocate_temp(DataType::DT_FLOAT,
TensorShape({num_boxes}),
&d_sorted_scores));
Tensor d_sorted_boxes;
OP_REQUIRES_OK(context, context->allocate_temp(DataType::DT_FLOAT,
TensorShape({num_boxes, 4}),
&d_sorted_boxes));
// this will return sorted scores and their indices
auto config = GetGpuLaunchConfig(num_boxes, device);
// initialize box and score indices
TF_CHECK_OK(GpuLaunchKernel(Iota<int>, config.block_count,
config.thread_per_block, 0, device.stream(),
config.virtual_thread_count, 0,
d_indices.flat<int>().data()));
TF_OP_REQUIRES_CUDA_SUCCESS(context, cudaGetLastError());
cuda_ret = cub::DeviceRadixSort::SortPairsDescending(
d_cub_sort_buffer.flat<int8>().data(), cub_sort_temp_storage_bytes,
scores.flat<float>().data(), d_sorted_scores.flat<float>().data(),
d_indices.flat<int>().data(), d_sorted_indices.flat<int>().data(),
num_boxes, 0,
8 * sizeof(float), // sort all bits
cuda_stream);
TF_OP_REQUIRES_CUDA_SUCCESS(context, cuda_ret);
// get pointers for easy access
const float4* original_boxes =
reinterpret_cast<const float4*>(boxes.flat<float>().data());
float4* sorted_boxes =
reinterpret_cast<float4*>(d_sorted_boxes.flat<float>().data());
const int* sorted_indices = d_sorted_indices.flat<int>().data();
// sort boxes using indices
TF_CHECK_OK(GpuLaunchKernel(IndexMultiSelect<int, float4>,
config.block_count, config.thread_per_block, 0,
device.stream(), config.virtual_thread_count,
sorted_indices, original_boxes, sorted_boxes));
int num_to_keep = 0;
// There is no guarantee that boxes are given in the for x1<x2 and/or y1<y2,
// flip boxes if necessary!
const bool flip_boxes = true;
auto status = NmsGpu(
d_sorted_boxes.flat<float>().data(), num_boxes, iou_threshold_val,
d_selected_indices.flat<int>().data(), &num_to_keep, context,
output_size, flip_boxes, /*legacy_mode*/ false);
TF_OP_REQUIRES_CUDA_SUCCESS(context, cudaGetLastError());
if (!status.ok()) {
context->SetStatus(status);
return;
}
Tensor* output_indices = nullptr;
int num_outputs = std::min(num_to_keep, output_size); // no padding!
OP_REQUIRES_OK(context,
context->allocate_output(0, TensorShape({num_outputs}),
&output_indices));
if (num_outputs == 0) return;
config = GetGpuLaunchConfig(num_outputs, device);
TF_CHECK_OK(GpuLaunchKernel(
IndexMultiSelect<int, int>, config.block_count, config.thread_per_block,
0, device.stream(), config.virtual_thread_count,
d_selected_indices.flat<int>().data(), sorted_indices,
(*output_indices).flat<int>().data()));
TF_OP_REQUIRES_CUDA_SUCCESS(context, cudaGetLastError());
}
};
struct GreaterThanCubOp {
float threshold_;
__host__ __device__ __forceinline__ GreaterThanCubOp(float threshold)
@ -597,6 +419,180 @@ Status CountIf(OpKernelContext* context, const float* dev_array, const Op& op,
return Status::OK();
}
Status DoNMS(OpKernelContext* context, const Tensor& boxes,
const Tensor& scores, const int64_t max_output_size,
const float iou_threshold_val, const float score_threshold) {
const int output_size = max_output_size;
int num_boxes = boxes.dim_size(0);
size_t cub_sort_temp_storage_bytes = 0;
auto cuda_stream = GetGpuStream(context);
auto device = context->eigen_gpu_device();
// Calling cub with nullptrs as inputs will make it return
// workspace size needed for the operation instead of doing the operation.
// In this specific instance, cub_sort_temp_storage_bytes will contain the
// necessary workspace size for sorting after the call.
if (num_boxes == 0) {
Tensor* output_indices = nullptr;
TF_RETURN_IF_ERROR(
context->allocate_output(0, TensorShape({0}), &output_indices));
return Status::OK();
}
cudaError_t cuda_ret = cub::DeviceRadixSort::SortPairsDescending(
nullptr, cub_sort_temp_storage_bytes,
static_cast<float*>(nullptr), // scores
static_cast<float*>(nullptr), // sorted scores
static_cast<int*>(nullptr), // input indices
static_cast<int*>(nullptr), // sorted indices
num_boxes, // num items
0, 8 * sizeof(float), // sort all bits
cuda_stream);
TF_RETURN_IF_CUDA_ERROR(cuda_ret);
Tensor d_cub_sort_buffer;
TF_RETURN_IF_ERROR(context->allocate_temp(
DataType::DT_INT8, TensorShape({(int64)cub_sort_temp_storage_bytes}),
&d_cub_sort_buffer));
Tensor d_indices;
TF_RETURN_IF_ERROR(context->allocate_temp(
DataType::DT_INT32, TensorShape({num_boxes}), &d_indices));
Tensor d_sorted_indices;
TF_RETURN_IF_ERROR(context->allocate_temp(
DataType::DT_INT32, TensorShape({num_boxes}), &d_sorted_indices));
Tensor d_selected_indices;
TF_RETURN_IF_ERROR(context->allocate_temp(
DataType::DT_INT32, TensorShape({num_boxes}), &d_selected_indices));
Tensor d_sorted_scores;
TF_RETURN_IF_ERROR(context->allocate_temp(
DataType::DT_FLOAT, TensorShape({num_boxes}), &d_sorted_scores));
Tensor d_sorted_boxes;
TF_RETURN_IF_ERROR(context->allocate_temp(
DataType::DT_FLOAT, TensorShape({num_boxes, 4}), &d_sorted_boxes));
// this will return sorted scores and their indices
auto config = GetGpuLaunchConfig(num_boxes, device);
// initialize box and score indices
TF_CHECK_OK(GpuLaunchKernel(Iota<int>, config.block_count,
config.thread_per_block, 0, device.stream(),
config.virtual_thread_count, 0,
d_indices.flat<int>().data()));
TF_RETURN_IF_CUDA_ERROR(cudaGetLastError());
cuda_ret = cub::DeviceRadixSort::SortPairsDescending(
d_cub_sort_buffer.flat<int8>().data(), cub_sort_temp_storage_bytes,
scores.flat<float>().data(), d_sorted_scores.flat<float>().data(),
d_indices.flat<int>().data(), d_sorted_indices.flat<int>().data(),
num_boxes, 0,
8 * sizeof(float), // sort all bits
cuda_stream);
TF_RETURN_IF_CUDA_ERROR(cuda_ret);
// get pointers for easy access
const float4* original_boxes =
reinterpret_cast<const float4*>(boxes.flat<float>().data());
float4* sorted_boxes =
reinterpret_cast<float4*>(d_sorted_boxes.flat<float>().data());
const int* sorted_indices = d_sorted_indices.flat<int>().data();
// sort boxes using indices
TF_CHECK_OK(GpuLaunchKernel(IndexMultiSelect<int, float4>, config.block_count,
config.thread_per_block, 0, device.stream(),
config.virtual_thread_count, sorted_indices,
original_boxes, sorted_boxes));
int limited_num_boxes = num_boxes;
// filter boxes by scores if nms v3
if (score_threshold > std::numeric_limits<float>::min()) {
GreaterThanCubOp score_limit(score_threshold);
TF_RETURN_IF_ERROR(CountIf(context, d_sorted_scores.flat<float>().data(),
score_limit, num_boxes, &limited_num_boxes));
if (limited_num_boxes == 0) {
Tensor* output_indices = nullptr;
VLOG(1) << "Number of boxes above score threshold " << score_threshold
<< " is 0";
TF_RETURN_IF_ERROR(
context->allocate_output(0, TensorShape({0}), &output_indices));
return Status::OK();
} else {
VLOG(2) << "Number of boxes above threshold=" << score_threshold
<< " is " << limited_num_boxes;
}
}
int num_to_keep = 0;
// There is no guarantee that boxes are given in the for x1<x2 and/or y1<y2,
// flip boxes if necessary!
const bool flip_boxes = true;
auto status = NmsGpu(d_sorted_boxes.flat<float>().data(), limited_num_boxes,
iou_threshold_val, d_selected_indices.flat<int>().data(),
&num_to_keep, context, output_size, flip_boxes);
TF_RETURN_IF_CUDA_ERROR(cudaGetLastError());
if (!status.ok()) {
context->SetStatus(status);
return status;
}
Tensor* output_indices = nullptr;
int num_outputs = std::min(num_to_keep, output_size); // no padding!
TF_RETURN_IF_ERROR(
context->allocate_output(0, TensorShape({num_outputs}), &output_indices));
if (num_outputs == 0) return Status::OK();
config = GetGpuLaunchConfig(num_outputs, device);
TF_CHECK_OK(GpuLaunchKernel(
IndexMultiSelect<int, int>, config.block_count, config.thread_per_block,
0, device.stream(), config.virtual_thread_count,
d_selected_indices.flat<int>().data(), sorted_indices,
(*output_indices).flat<int>().data()));
TF_RETURN_IF_CUDA_ERROR(cudaGetLastError());
return Status::OK();
}
class NonMaxSuppressionV2GPUOp : public OpKernel {
public:
explicit NonMaxSuppressionV2GPUOp(OpKernelConstruction* context)
: OpKernel(context) {}
void Compute(OpKernelContext* context) override {
// boxes: [num_boxes, 4]
const Tensor& boxes = context->input(0);
// scores: [num_boxes]
const Tensor& scores = context->input(1);
// max_output_size: scalar
const Tensor& max_output_size = context->input(2);
OP_REQUIRES(
context, TensorShapeUtils::IsScalar(max_output_size.shape()),
errors::InvalidArgument("max_output_size must be 0-D, got shape ",
max_output_size.shape().DebugString()));
// iou_threshold: scalar
const Tensor& iou_threshold = context->input(3);
OP_REQUIRES(context, TensorShapeUtils::IsScalar(iou_threshold.shape()),
errors::InvalidArgument("iou_threshold must be 0-D, got shape ",
iou_threshold.shape().DebugString()));
const float iou_threshold_val = iou_threshold.scalar<float>()();
OP_REQUIRES(context, iou_threshold_val >= 0 && iou_threshold_val <= 1,
errors::InvalidArgument("iou_threshold must be in [0, 1]"));
OP_REQUIRES(context, boxes.dims() == 2,
errors::InvalidArgument("boxes must be a rank 2 tensor!"));
int num_boxes = boxes.dim_size(0);
OP_REQUIRES(context, boxes.dim_size(1) == 4,
errors::InvalidArgument("boxes must be Nx4"));
OP_REQUIRES(context, scores.dims() == 1,
errors::InvalidArgument("scores must be a vector!"));
OP_REQUIRES(
context, scores.dim_size(0) == num_boxes,
errors::InvalidArgument(
"scores has incompatible shape")); // message must be exactly this
// otherwise tests fail!
if (num_boxes == 0) {
Tensor* output_indices = nullptr;
OP_REQUIRES_OK(context,
context->allocate_output(0, TensorShape({0}), &output_indices));
return;
}
const int64_t output_size = max_output_size.scalar<int>()();
OP_REQUIRES_OK(
context,
DoNMS(context, boxes, scores, output_size, iou_threshold_val,
/*score_threshold is float min if score threshold is disabled*/
std::numeric_limits<float>::min()));
}
};
class NonMaxSuppressionV3GPUOp : public OpKernel {
public:
explicit NonMaxSuppressionV3GPUOp(OpKernelConstruction* context)
@ -648,131 +644,8 @@ class NonMaxSuppressionV3GPUOp : public OpKernel {
return;
}
const int output_size = max_output_size.scalar<int>()();
size_t cub_sort_temp_storage_bytes = 0;
auto cuda_stream = tensorflow::GetGpuStream(context);
auto device = context->eigen_gpu_device();
// Calling cub with nullptrs as inputs will make it return
// workspace size needed for the operation instead of doing the operation.
// In this specific instance, cub_sort_temp_storage_bytes will contain the
// necessary workspace size for sorting after the call.
cudaError_t cuda_ret = cub::DeviceRadixSort::SortPairsDescending(
nullptr, cub_sort_temp_storage_bytes,
static_cast<float*>(nullptr), // scores
static_cast<float*>(nullptr), // sorted scores
static_cast<int*>(nullptr), // input indices
static_cast<int*>(nullptr), // sorted indices
num_boxes, // num items
0, 8 * sizeof(float), // sort all bits
cuda_stream);
TF_OP_REQUIRES_CUDA_SUCCESS(context, cuda_ret);
Tensor d_cub_sort_buffer;
OP_REQUIRES_OK(context,
context->allocate_temp(
DataType::DT_INT8,
TensorShape({(int64)cub_sort_temp_storage_bytes}),
&d_cub_sort_buffer));
Tensor d_indices;
OP_REQUIRES_OK(
context, context->allocate_temp(DataType::DT_INT32,
TensorShape({num_boxes}), &d_indices));
Tensor d_sorted_indices;
OP_REQUIRES_OK(context, context->allocate_temp(DataType::DT_INT32,
TensorShape({num_boxes}),
&d_sorted_indices));
Tensor d_selected_indices;
OP_REQUIRES_OK(context, context->allocate_temp(DataType::DT_INT32,
TensorShape({num_boxes}),
&d_selected_indices));
Tensor d_sorted_scores;
OP_REQUIRES_OK(context, context->allocate_temp(DataType::DT_FLOAT,
TensorShape({num_boxes}),
&d_sorted_scores));
Tensor d_sorted_boxes;
OP_REQUIRES_OK(context, context->allocate_temp(DataType::DT_FLOAT,
TensorShape({num_boxes, 4}),
&d_sorted_boxes));
// this will return sorted scores and their indices
auto config = GetGpuLaunchConfig(num_boxes, device);
// initialize box and score indices
TF_CHECK_OK(GpuLaunchKernel(Iota<int>, config.block_count,
config.thread_per_block, 0, device.stream(),
config.virtual_thread_count, 0,
d_indices.flat<int>().data()));
TF_OP_REQUIRES_CUDA_SUCCESS(context, cudaGetLastError());
cuda_ret = cub::DeviceRadixSort::SortPairsDescending(
d_cub_sort_buffer.flat<int8>().data(), cub_sort_temp_storage_bytes,
scores.flat<float>().data(), d_sorted_scores.flat<float>().data(),
d_indices.flat<int>().data(), d_sorted_indices.flat<int>().data(),
num_boxes, 0,
8 * sizeof(float), // sort all bits
cuda_stream);
TF_OP_REQUIRES_CUDA_SUCCESS(context, cuda_ret);
// get pointers for easy access
const float4* original_boxes =
reinterpret_cast<const float4*>(boxes.flat<float>().data());
float4* sorted_boxes =
reinterpret_cast<float4*>(d_sorted_boxes.flat<float>().data());
const int* sorted_indices = d_sorted_indices.flat<int>().data();
// sort boxes using indices
TF_CHECK_OK(GpuLaunchKernel(IndexMultiSelect<int, float4>,
config.block_count, config.thread_per_block, 0,
device.stream(), config.virtual_thread_count,
sorted_indices, original_boxes, sorted_boxes));
// Unfortunately we had to sort scores to find the number of boxes which has
// a threshold above score_threshold_val. It can be done before sorting but
// that would require either implementing a custom sort or a generic random
// access iterator for cub. For the time being we search for the location of
// the score_threshold_val in the sorted array and limit num_boxes to its
// index.
GreaterThanCubOp score_limit(score_threshold_val);
int limited_num_boxes = 0;
OP_REQUIRES_OK(context,
CountIf(context, d_sorted_scores.flat<float>().data(),
score_limit, num_boxes, &limited_num_boxes));
if (limited_num_boxes == 0) {
Tensor* output_indices = nullptr;
VLOG(1) << "Number of boxes above score threshold " << score_threshold_val
<< " is 0";
OP_REQUIRES_OK(context, context->allocate_output(0, TensorShape({0}),
&output_indices));
return;
} else {
VLOG(2) << "Number of boxes above threshold=" << score_threshold_val
<< " is " << limited_num_boxes;
}
int num_to_keep = 0;
// There is no guarantee that boxes are given in the for x1<x2 and/or y1<y2,
// flip boxes if necessary!
const bool flip_boxes = true;
auto status = NmsGpu(
d_sorted_boxes.flat<float>().data(), limited_num_boxes,
iou_threshold_val, d_selected_indices.flat<int>().data(), &num_to_keep,
context, output_size, flip_boxes, /*legacy_mode*/ false);
TF_OP_REQUIRES_CUDA_SUCCESS(context, cudaGetLastError());
if (!status.ok()) {
context->SetStatus(status);
return;
}
Tensor* output_indices = nullptr;
int num_outputs = std::min(num_to_keep, output_size); // no padding!
OP_REQUIRES_OK(context,
context->allocate_output(0, TensorShape({num_outputs}),
&output_indices));
if (num_outputs == 0) {
VLOG(1) << "No outputs!";
return;
} else {
VLOG(2) << "Num outputs= " << num_outputs;
}
config = GetGpuLaunchConfig(num_outputs, device);
TF_CHECK_OK(GpuLaunchKernel(
IndexMultiSelect<int, int>, config.block_count, config.thread_per_block,
0, device.stream(), config.virtual_thread_count,
d_selected_indices.flat<int>().data(), sorted_indices,
(*output_indices).flat<int>().data()));
TF_OP_REQUIRES_CUDA_SUCCESS(context, cudaGetLastError());
OP_REQUIRES_OK(context, DoNMS(context, boxes, scores, output_size,
iou_threshold_val, score_threshold_val));
}
};

View File

@ -54,8 +54,7 @@ extern const int kNmsBoxesPerTread;
Status NmsGpu(const float* d_sorted_boxes_float_ptr, const int num_boxes,
const float iou_threshold, int* d_selected_indices,
int* h_num_boxes_to_keep, OpKernelContext* context,
const int max_boxes, bool flip_boxes = false,
bool legacy_mode = false);
const int max_boxes, bool flip_boxes = false);
#endif
} // namespace tensorflow