Add ssd op with ir builder (#1095)

Jenkinsfile

@@ -126,6 +126,7 @@ stage('Build') {
            echo USE_SORT=1 >> config.mk
            echo USE_OPENGL=1 >> config.mk
            echo LLVM_CONFIG=llvm-config-4.0 >> config.mk
+           echo USE_SORT=1 >> config.mk
            """
         make('cpu', '-j2')
         pack_lib('cpu', tvm_lib)

Makefile

@@ -201,6 +201,7 @@ ifeq ($(USE_GRAPH_RUNTIME_DEBUG), 1)
 endif
 
 include make/contrib/cblas.mk
+include make/contrib/sort.mk
 include make/contrib/random.mk
 include make/contrib/nnpack.mk
 include make/contrib/cudnn.mk

make/config.mk

@@ -90,3 +90,6 @@ USE_CUBLAS = 0
 
 # Whether use rocBlas
 USE_ROCBLAS = 0
+
+# Whether use contrib sort
+USE_SORT = 0

make/contrib/sort.mk

+SORT_CONTRIB_SRC = $(wildcard src/contrib/sort/*.cc)
+SORT_CONTRIB_OBJ = $(patsubst src/%.cc, build/%.o, $(SORT_CONTRIB_SRC))
+
+ifeq ($(USE_SORT), 1)
+    RUNTIME_DEP += $(SORT_CONTRIB_OBJ)
+endif

python/tvm/api.py

@@ -300,7 +300,14 @@ def scan(init, update, state_placeholder, inputs=None, name="scan", tag=""):
     return res[0] if len(res) == 1 else res
 
 
-def extern(shape, inputs, fcompute, name="extern", dtype=None, tag=""):
+def extern(shape,
+           inputs,
+           fcompute,
+           name="extern",
+           dtype=None,
+           in_buffers=None,
+           out_buffers=None,
+           tag=""):
     """Compute several tensor via extern function.
 
     Parameters
@@ -332,6 +339,12 @@ def extern(shape, inputs, fcompute, name="extern", dtype=None, tag=""):
         The data types of outputs,
         by default dtype will be same as inputs.
 
+    in_buffers: Buffer or list of Buffer, optional
+        Input buffers.
+
+    out_buffers: Buffer or list of Buffers, optional
+        Output buffers.
+
     Returns
     -------
     tensor: Tensor or list of Tensors
@@ -357,14 +370,25 @@ def extern(shape, inputs, fcompute, name="extern", dtype=None, tag=""):
         tag = _tag.TagScope.current.tag
     shape = (shape,) if isinstance(shape, (_expr.Expr, _Integral)) else shape
     shape = [shape] if isinstance(shape[0], (_expr.Expr, _Integral)) else shape
-    input_placeholders = []
-    output_placeholders = []
+    if in_buffers is not None:
+        in_buffers = [in_buffers] if not isinstance(in_buffers, list) else in_buffers
+        if len(inputs) != len(in_buffers):
+            raise RuntimeError("Number of inputs and in_buffers mismatch: %d vs %d."
+                               % (len(inputs), len(in_buffers)))
+    if out_buffers is not None:
+        out_buffers = [out_buffers] if not isinstance(out_buffers, list) else out_buffers
+        if len(shape) != len(out_buffers):
+            raise RuntimeError("Number of outputs and out_buffers mismatch: %d vs %d."
+                               % (len(shape), len(out_buffers)))
+    input_placeholders = in_buffers or []
+    output_placeholders = out_buffers or []
     types = set()
     for t in inputs:
         if not isinstance(t, _tensor.Tensor):
             raise ValueError("expect inputs to be tensor")
-        input_placeholders.append(
-            decl_buffer(t.shape, t.dtype, t.op.name))
+        if in_buffers is None:
+            input_placeholders.append(
+                decl_buffer(t.shape, t.dtype, t.op.name))
         types.add(t.dtype)
 
     if dtype is None:
@@ -375,8 +399,9 @@ def extern(shape, inputs, fcompute, name="extern", dtype=None, tag=""):
     if isinstance(dtype, str):
         dtype = [dtype]
 
-    for shp, dt in zip(shape, dtype):
-        output_placeholders.append(decl_buffer(shp, dt, name))
+    if out_buffers is None:
+        for shp, dt in zip(shape, dtype):
+            output_placeholders.append(decl_buffer(shp, dt, name))
     body = fcompute(input_placeholders, output_placeholders)
     if isinstance(body, _expr.Expr):
         body = _make.Evaluate(body)

src/contrib/sort/sort.cc

+/*!
+ *  Copyright (c) 2017 by Contributors
+ * \file Use standard C library call.
+ */
+
+#include <tvm/runtime/registry.h>
+#include <tvm/runtime/util.h>
+#include <dlpack/dlpack.h>
+#include <algorithm>
+#include <vector>
+
+namespace tvm {
+namespace contrib {
+
+using namespace runtime;
+
+template<typename DType>
+bool CompareAscend(const std::pair<int32_t, DType>& lhs,
+                   const std::pair<int32_t, DType>& rhs) {
+  return lhs.second < rhs.second;
+}
+
+template<typename DType>
+bool CompareDescend(const std::pair<int32_t, DType>& lhs,
+                    const std::pair<int32_t, DType>& rhs) {
+  return lhs.second > rhs.second;
+}
+
+
+// Argsort implemented C library sort.
+// Return indices of sorted tensor.
+// By default, the last axis will be used to sort.
+// sort_num specify the number of elements to be sorted.
+// If input tensor has dimension (d0, d1, ..., d(k-1), dk, d(k+1), ..., d(n-1))
+// and sort axis is dk. sort_num should have dimension of
+// (d1, d2, ..., d(k-1), d(k+1), ..., dn).
+TVM_REGISTER_GLOBAL("tvm.contrib.sort.argsort")
+.set_body([](TVMArgs args, TVMRetValue *ret) {
+  DLTensor *input = args[0];
+  DLTensor *sort_num = args[1];
+  DLTensor *output = args[2];
+  int32_t axis = args[3];
+  bool is_descend = args[4];
+
+  auto dtype = input->dtype;
+  auto data_ptr = static_cast<float *>(input->data);
+  auto sort_num_ptr = static_cast<int32_t *>(sort_num->data);
+  std::vector<std::pair<int32_t, float>> sorter;
+  int64_t axis_mul_before = 1;
+  int64_t axis_mul_after = 1;
+
+  if (axis < 0) {
+    axis = input->ndim + axis;
+  }
+
+  // Currently only supports input dtype to be float32.
+  CHECK_EQ(dtype.code, 2) << "Currently only supports input dtype "
+      "to be float32.";
+  CHECK_EQ(dtype.bits, 32) << "Currently only supports input dtype "
+      "to be float32.";
+  CHECK_LT(axis, input->ndim) << "Axis out of boundary for "
+      "input ndim " << input->ndim;
+
+  for (int i = 0; i < input->ndim; ++i) {
+    if (i < axis) {
+      axis_mul_before *= input->shape[i];
+    } else if (i > axis) {
+      axis_mul_after *= input->shape[i];
+    }
+  }
+
+  for (int64_t i = 0 ; i < axis_mul_before; ++i) {
+    for (int64_t j = 0 ; j < axis_mul_after; ++j) {
+      sorter.clear();
+      int32_t current_sort_num = *(sort_num_ptr + i * axis_mul_after + j);
+      int64_t base_idx = i * input->shape[axis] * axis_mul_after + j;
+      for (int64_t k = 0; k < current_sort_num; ++k) {
+        int64_t full_idx = base_idx + k * axis_mul_after;
+        sorter.emplace_back(std::make_pair(k, *(data_ptr + full_idx)));
+      }
+      std::stable_sort(sorter.begin(), sorter.end(),
+                       is_descend ? CompareDescend<float>
+                                  : CompareAscend<float>);
+      for (int32_t k = 0; k < input->shape[axis]; ++k) {
+        *(static_cast<int32_t *>(output->data) + base_idx + k * axis_mul_after)
+          = k < sorter.size() ? sorter[k].first : k;
+      }
+    }
+  }
+});
+
+}  // namespace contrib
+}  // namespace tvm

tests/python/contrib/test_sort.py

+import tvm
+import numpy as np
+
+def test_sort():
+    n = 2
+    l = 5
+    m = 3
+    data = tvm.placeholder((n, l, m), name='data')
+    sort_num = tvm.placeholder((n, m), name="sort_num", dtype="int32")
+    axis = 1
+    is_descend = True
+    out = tvm.extern(data.shape, [data, sort_num],
+                     lambda ins, outs: tvm.call_packed(
+                         "tvm.contrib.sort.argsort", ins[0],
+                         ins[1], outs[0], axis, is_descend),
+                     dtype='int32', name="sort_tensor")
+    input = [[[1, 2, 3], [2, 4.5, 3.5], [1.1, 0.5, 1], [3.2, -5, 0.5], [1.5, 0, 0]],
+             [[1, 2, 3], [4, 5, 6], [7, 8, 9], [10, 11, 12], [13, 14, 15]]]
+    sort_num_input = [[1, 2, 3], [4, 5, 5]]
+    sorted_index = [[[0, 1, 1], [1, 0, 0], [2, 2, 2], [3, 3, 3], [4, 4, 4]],
+                    [[3, 4, 4], [2, 3, 3], [1, 2, 2], [0, 1, 1], [4, 0, 0]]]
+
+    ctx = tvm.cpu(0)
+    target = "llvm"
+    s = tvm.create_schedule(out.op)
+    f = tvm.build(s, [data, sort_num, out], target)
+    a = tvm.nd.array(np.array(input).astype(data.dtype), ctx)
+    b = tvm.nd.array(np.array(sort_num_input).astype(sort_num.dtype), ctx)
+    c = tvm.nd.array(np.zeros(a.shape, dtype=out.dtype), ctx)
+    f(a, b, c)
+    np.testing.assert_allclose(c.asnumpy(), np.array(sorted_index).astype(out.dtype), rtol=1e-5)
+
+def test_sort_np():
+    dshape = (1, 2, 3, 4, 5, 6)
+    axis = 4
+    reduced_shape = (1, 2, 3, 4, 6)
+    is_descend = False
+    data = tvm.placeholder(dshape, name='data')
+    sort_num = tvm.placeholder(reduced_shape, name="sort_num", dtype="int32")
+    out = tvm.extern(data.shape, [data, sort_num],
+                     lambda ins, outs: tvm.call_packed(
+                         "tvm.contrib.sort.argsort", ins[0],
+                         ins[1], outs[0], axis, is_descend),
+                     dtype='int32', name="sort_tensor")
+
+    ctx = tvm.cpu(0)
+    target = "llvm"
+    s = tvm.create_schedule(out.op)
+    f = tvm.build(s, [data, sort_num, out], target)
+
+    np_data = np.random.uniform(size=dshape)
+    np_out = np.argsort(np_data, axis=axis)
+    sort_num_input = np.full(reduced_shape, dshape[axis])
+    a = tvm.nd.array(np.array(np_data).astype(data.dtype), ctx)
+    b = tvm.nd.array(np.array(sort_num_input).astype(sort_num.dtype), ctx)
+    c = tvm.nd.array(np.zeros(a.shape, dtype=out.dtype), ctx)
+    f(a, b, c)
+    np.testing.assert_allclose(c.asnumpy(), np_out, rtol=1e-5)
+
+if __name__ == "__main__":
+    test_sort()
+    test_sort_np()

topi/python/topi/cuda/vision.py

-# pylint: disable=invalid-name, unused-variable
+# pylint: disable=invalid-name, unused-variable, unused-argument
 """Schedule for vision operators"""
 from __future__ import absolute_import as _abs
 import tvm
@@ -40,3 +40,37 @@ def schedule_region(outs):
     target = tvm.target.current_target(allow_none=False)
     cpp_target = cpp.TEST_create_target(target.target_name)
     return cpp.cuda.schedule_region(cpp_target, outs)
+
+@generic.schedule_multibox_prior.register(["cuda", "gpu"])
+def schedule_multibox_prior(out):
+    """Schedule for multibox_prior operator.
+
+    Parameters
+    ----------
+    outs: Array of Tensor
+        The computation graph description of multibox_prior
+        in the format of an array of tensors.
+
+    Returns
+    -------
+    s: Schedule
+        The computation schedule for multibox_prior.
+    """
+    raise RuntimeError("Currently multibox_prior only supports CPU.")
+
+@generic.schedule_multibox_detection.register(["cuda", "gpu"])
+def schedule_multibox_detection(out):
+    """Schedule for multibox_detection operator.
+
+    Parameters
+    ----------
+    outs: Array of Tensor
+        The computation graph description of multibox_detection
+        in the format of an array of tensors.
+
+    Returns
+    -------
+    s: Schedule
+        The computation schedule for multibox_detection.
+    """
+    raise RuntimeError("Currently multibox_detection only supports CPU.")

topi/python/topi/generic/vision.py

+# pylint: disable=invalid-name, no-member
 """Generic vision operators"""
 from __future__ import absolute_import as _abs
 import tvm
@@ -70,3 +71,72 @@ def schedule_region(outs):
     target = tvm.target.current_target(allow_none=False)
     cpp_target = cpp.TEST_create_target(target.target_name)
     return cpp.generic.default_schedule(cpp_target, outs, False)
+
+@tvm.target.generic_func
+def schedule_nms(outs):
+    """Schedule for non-maximum suppression
+
+    Parameters
+    ----------
+    outs: Array of Tensor
+      The computation graph description of nms
+      in the format of an array of tensors.
+
+    Returns
+    -------
+    s: Schedule
+      The computation schedule for the op.
+    """
+    return _default_schedule(outs, False)
+
+@tvm.target.generic_func
+def schedule_multibox_prior(outs):
+    """Schedule for multibox_prior
+
+    Parameters
+    ----------
+    outs: Array of Tensor
+      The computation graph description of multibox_prior
+      in the format of an array of tensors.
+
+    Returns
+    -------
+    s: Schedule
+      The computation schedule for the op.
+    """
+    return _default_schedule(outs, False)
+
+@tvm.target.generic_func
+def schedule_multibox_transform_loc(outs):
+    """Schedule for multibox_transform_loc
+
+    Parameters
+    ----------
+    outs: Array of Tensor
+      The computation graph description of
+      multibox_transform_loc in the format
+      of an array of tensors.
+
+    Returns
+    -------
+    s: Schedule
+      The computation schedule for the op.
+    """
+    return _default_schedule(outs, False)
+
+@tvm.target.generic_func
+def schedule_multibox_detection(outs):
+    """Schedule for multibox_detection
+
+    Parameters
+    ----------
+    outs: Array of Tensor
+      The computation graph description of multibox_detection
+      in the format of an array of tensors.
+
+    Returns
+    -------
+    s: Schedule
+      The computation schedule for the op.
+    """
+    return _default_schedule(outs, False)

topi/python/topi/nn/util.py

 # pylint: disable=invalid-name, unused-variable
 """NN operator common utilities"""
 from __future__ import absolute_import
+
+import tvm
 from ..util import get_const_int
 
 def infer_pad(data, data_pad):
@@ -53,8 +55,8 @@ def infer_stride(data, kernel, out):
     _, _, IH, IW = data.shape
     _, _, KH, KW = kernel.shape
     _, _, OH, OW = out.shape
-    hstride = (IH - KH) // (OH - 1)
-    wstride = (IW - KW) // (OW - 1)
+    hstride = (IH - KH) // tvm.make.Max(OH - 1, 1) + tvm.select(OH == 1, 1, 0)
+    wstride = (IW - KW) // tvm.make.Max(OW - 1, 1) + tvm.select(OW == 1, 1, 0)
     return get_const_int(hstride), get_const_int(wstride)
 
 

topi/python/topi/vision/__init__.py

@@ -2,6 +2,7 @@
 """VISION network operators"""
 from __future__ import absolute_import as _abs
 
-from . import yolo2
+from . import yolo2, ssd
 from .shortcut import *
 from .reorg import *
+from .nms import *

topi/python/topi/vision/nms.py

+# pylint: disable=invalid-name, no-member, too-many-locals, too-many-arguments
+"""Non-maximum suppression operator"""
+import tvm
+
+from tvm import api
+
+def nms_ir(data, sort_result, valid_count, out, nms_threshold, force_suppress, nms_topk):
+    """Low level IR routing for transform location in multibox_detection operator.
+
+    Parameters
+    ----------
+    data: Buffer
+        Buffer of output boxes with class and score.
+
+    sort_result : Buffer
+        Buffer of output box indexes sorted by score.
+
+    valid_count : Buffer
+        Buffer of number of valid output boxes.
+
+    out : Buffer
+        Output buffer.
+
+    nms_threshold : float
+        Non-maximum suppression threshold.
+
+    force_suppress : boolean
+        Whether to suppress all detections regardless of class_id.
+
+    nms_topk : int
+        Keep maximum top k detections before nms, -1 for no limit.
+
+    Returns
+    -------
+    stmt : Stmt
+        The result IR statement.
+    """
+    def calculate_overlap(out_tensor, box_a_idx, box_b_idx):
+        """Calculate overlap of two boxes.
+        """
+        w = tvm.make.Max(0.0, tvm.make.Min(out_tensor[box_a_idx + 2], out_tensor[box_b_idx + 2])
+                         - tvm.make.Max(out_tensor[box_a_idx], out_tensor[box_b_idx]))
+        h = tvm.make.Max(0.0, tvm.make.Min(out_tensor[box_a_idx + 3], out_tensor[box_b_idx + 3])
+                         - tvm.make.Max(out_tensor[box_a_idx + 1], out_tensor[box_b_idx + 1]))
+        i = w * h
+        u = (out_tensor[box_a_idx + 2] - out_tensor[box_a_idx]) * \
+            (out_tensor[box_a_idx + 3] - out_tensor[box_a_idx + 1]) + \
+            (out_tensor[box_b_idx + 2] - out_tensor[box_b_idx]) * \
+            (out_tensor[box_b_idx + 3] - out_tensor[box_b_idx + 1]) - i
+        return tvm.select(u <= 0.0, 0.0, i / u)
+
+    ib = tvm.ir_builder.create()
+    p_data = ib.buffer_ptr(data)
+    p_sort_result = ib.buffer_ptr(sort_result)
+    p_valid_count = ib.buffer_ptr(valid_count)
+    p_out = ib.buffer_ptr(out)
+    batch_size = out.shape[0]
+    num_anchors = out.shape[1]
+
+    nms_threshold_node = tvm.make.node("FloatImm", dtype="float32", value=nms_threshold)
+    nms_topk_node = tvm.make.node("IntImm", dtype="int32", value=nms_topk)
+    force_suppress_node = tvm.make.node("IntImm", dtype="int32", value=1 if force_suppress else 0)
+    with ib.for_range(0, batch_size, for_type="parallel", name="n") as n:
+        with ib.if_scope(tvm.all(nms_threshold_node > 0, nms_threshold_node < 1,
+                                 p_valid_count[0] > 0)):
+            # Reorder output
+            nkeep = tvm.select(tvm.all(nms_topk_node > 0, nms_topk < p_valid_count[n]),
+                               nms_topk, p_valid_count[n])
+            with ib.for_range(0, nkeep, name="l") as l:
+                with ib.for_range(0, 6, name="m") as m:
+                    p_out[(n * num_anchors * 6
+                           + l * 6 + m)] = p_data[(n * num_anchors * 6
+                                                   + p_sort_result[n * num_anchors + l] * 6 + m)]
+            with ib.if_scope(tvm.all(nms_topk_node > 0, nms_topk < p_valid_count[n])):
+                with ib.for_range(0, p_valid_count[n] - nkeep, name="l") as l:
+                    with ib.for_range(0, 6, name="m") as m:
+                        p_out[(n * num_anchors * 6
+                               + (l + nkeep) * 6 + m)] = p_data[(n * num_anchors * 6
+                                                                 + (l + nkeep) * 6 + m)]
+            # Apply nms
+            with ib.for_range(0, p_valid_count[n], name="l") as l:
+                offset_l = l * 6
+                with ib.if_scope(p_out[n * num_anchors * 6 + offset_l] >= 0):
+                    with ib.for_range(0, p_valid_count[n], name="m") as m:
+                        offset_m = m * 6
+                        with ib.if_scope(tvm.all(m > l, p_out[n * num_anchors * 6
+                                                              + offset_m] >= 0)):
+                            with ib.if_scope(tvm.any(force_suppress_node > 0,
+                                                     p_out[n * num_anchors * 6 + offset_l] ==
+                                                     p_out[n * num_anchors * 6 + offset_m])):
+                                # When force_suppress == True or class_id equals
+                                iou = calculate_overlap(p_out, n * num_anchors * 6 + offset_l + 2,
+                                                        n * num_anchors * 6 + offset_m + 2)
+                                with ib.if_scope(iou >= nms_threshold):
+                                    p_out[n * num_anchors * 6 + offset_m] = -1.0
+        with ib.else_scope():
+            with ib.for_range(0, p_valid_count[n], name="l") as l:
+                with ib.for_range(0, 6, name="m") as m:
+                    p_out[(n * num_anchors * 6
+                           + l * 6 + m)] = p_data[n * num_anchors * 6 + l * 6 + m]
+        # Set invalid entry to be -1
+        with ib.for_range(0, num_anchors - p_valid_count[n], name="l") as l:
+            with ib.for_range(0, 6, name="m") as m:
+                p_out[n * num_anchors * 6 + (l + p_valid_count[n]) * 6 + m] = -1.0
+    return ib.get()
+
+
+@tvm.target.generic_func
+def nms(data, valid_count, nms_threshold=0.5, force_suppress=False, nms_topk=-1):
+    """Non-maximum suppression operator for object detection.
+
+    Parameters
+    ----------
+    data: tvm.Tensor
+        3-D tensor with shape [batch_size, num_anchors, 6].
+        The last dimension should be in format of
+        [class_id, score, box_left, box_top, box_right, box_bottom].
+
+    valid_count : tvm.Tensor
+        1-D tensor for valid number of boxes.
+
+    nms_threshold : float
+        Non-maximum suppression threshold.
+
+    force_suppress : boolean
+        Whether to suppress all detections regardless of class_id.
+
+    nms_topk : int
+        Keep maximum top k detections before nms, -1 for no limit.
+
+    Returns
+    -------
+    out : tvm.Tensor
+        3-D tensor with shape [batch_size, num_anchors, 6].
+
+    Example
+    --------
+    .. code-block:: python
+
+        # An example to use nms
+        dshape = (1, 5, 6)
+        data = tvm.placeholder(dshape, name="data")
+        valid_count = tvm.placeholder((dshape[0],), dtype="int32", name="valid_count")
+        nms_threshold = 0.7
+        force_suppress = True
+        nms_topk = -1
+        out = nms(data, valid_count, nms_threshold, force_suppress, nms_topk)
+        np_data = np.random.uniform(dshape)
+        np_valid_count = np.array([4])
+        s = topi.generic.schedule_nms(out)
+        f = tvm.build(s, [data, valid_count, out], "llvm")
+        ctx = tvm.cpu()
+        tvm_data = tvm.nd.array(np_data, ctx)
+        tvm_valid_count = tvm.nd.array(np_valid_count, ctx)
+        tvm_out = tvm.nd.array(np.zeros(dshape, dtype=data.dtype), ctx)
+        f(tvm_data, tvm_valid_count, tvm_out)
+    """
+    batch_size = data.shape[0]
+    num_anchors = data.shape[1]
+    valid_count_dtype = "int32"
+    valid_count_buf = api.decl_buffer(valid_count.shape, valid_count_dtype,
+                                      "valid_count_buf", data_alignment=4)
+    data_buf = api.decl_buffer(data.shape, data.dtype, "data_buf", data_alignment=8)
+    score_axis = 1
+    score_shape = (batch_size, num_anchors)
+    score_tensor = tvm.compute(score_shape, lambda i, j: data[i, j, score_axis])
+    score_tensor_buf = api.decl_buffer(score_tensor.shape, data.dtype,
+                                       "score_tensor_buf", data_alignment=8)
+    sort_tensor_dtype = "int32"
+    sort_tensor_buf = api.decl_buffer(score_shape, sort_tensor_dtype,
+                                      "sort_tensor_buf", data_alignment=8)
+    sort_tensor = \
+        tvm.extern(score_shape,
+                   [score_tensor, valid_count],
+                   lambda ins, outs: tvm.call_packed(
+                       "tvm.contrib.sort.argsort", ins[0], ins[1],
+                       outs[0], score_axis, True),
+                   dtype=sort_tensor_dtype,
+                   in_buffers=[score_tensor_buf, valid_count_buf],
+                   out_buffers=sort_tensor_buf,
+                   name="nms_sort")
+    out = \
+        tvm.extern(data.shape,
+                   [data, sort_tensor, valid_count],
+                   lambda ins, outs: nms_ir(
+                       ins[0], ins[1], ins[2], outs[0], nms_threshold,
+                       force_suppress, nms_topk),
+                   dtype="float32",
+                   in_buffers=[data_buf, sort_tensor_buf, valid_count_buf],
+                   tag="nms")
+    return out

topi/python/topi/vision/ssd/__init__.py

+# pylint: disable=wildcard-import
+"""VISION network operators"""
+from __future__ import absolute_import as _abs
+
+from .multibox import *

topi/tests/python/test_topi_vision.py

+"""Test code for vision package"""
+import numpy as np
+import tvm
+import topi
+import math
+
+from topi.vision import ssd, nms
+
+
+def test_nms():
+    dshape = (1, 5, 6)
+    data = tvm.placeholder(dshape, name="data")
+    valid_count = tvm.placeholder((dshape[0],), dtype="int32", name="valid_count")
+    nms_threshold = 0.7
+    force_suppress = True
+    nms_topk = 2
+    out = nms(data, valid_count, nms_threshold, force_suppress, nms_topk)
+
+    np_data = np.array([[[0, 0.8, 1, 20, 25, 45], [1, 0.7, 30, 60, 50, 80],
+                         [0, 0.4, 4, 21, 19, 40], [2, 0.9, 35, 61, 52, 79],
+                         [1, 0.5, 100, 60, 70, 110]]]).astype(data.dtype)
+    np_valid_count = np.array([4]).astype(valid_count.dtype)
+    np_result = np.array([[[2, 0.9, 35, 61, 52, 79], [0, 0.8, 1, 20, 25, 45],
+                           [0, 0.4, 4, 21, 19, 40], [-1, 0.9, 35, 61, 52, 79],
+                           [-1, -1, -1, -1, -1, -1]]])
+
+    def check_device(device):
+        ctx = tvm.context(device, 0)
+        if not ctx.exist:
+            print("Skip because %s is not enabled" % device)
+            return
+        print("Running on target: %s" % device)
+        with tvm.target.create(device):
+            s = topi.generic.schedule_nms(out)
+
+        tvm_data = tvm.nd.array(np_data, ctx)
+        tvm_valid_count = tvm.nd.array(np_valid_count, ctx)
+        tvm_out = tvm.nd.array(np.zeros(dshape, dtype=data.dtype), ctx)
+        f = tvm.build(s, [data, valid_count, out], device)
+        f(tvm_data, tvm_valid_count, tvm_out)
+        np.testing.assert_allclose(tvm_out.asnumpy(), np_result, rtol=1e-4)
+
+    for device in ['llvm']:
+        check_device(device)
+
+
+def verify_multibox_prior(dshape, sizes=(1,), ratios=(1,), steps=(-1, -1), offsets=(0.5, 0.5), clip=False):
+    data = tvm.placeholder(dshape, name="data")
+    out = ssd.multibox_prior(data, sizes, ratios, steps, offsets, clip)
+
+    dtype = data.dtype
+    input_data = np.random.uniform(size=dshape).astype(dtype)
+
+    in_height = data.shape[2].value
+    in_width = data.shape[3].value
+    num_sizes = len(sizes)
+    num_ratios = len(ratios)
+    size_ratio_concat = sizes + ratios
+    steps_h = steps[0] if steps[0] > 0 else 1.0 / in_height
+    steps_w = steps[1] if steps[1] > 0 else 1.0 / in_width
+    offset_h = offsets[0]
+    offset_w = offsets[1]
+
+    oshape = (1, in_height * in_width * (num_sizes + num_ratios - 1), 4)
+    np_out = np.zeros(oshape).astype(dtype)
+
+    for i in range(in_height):
+        center_h = (i + offset_h) * steps_h
+        for j in range(in_width):
+            center_w = (j + offset_w) * steps_w
+            for k in range(num_sizes + num_ratios - 1):
+                w = size_ratio_concat[k] * in_height / in_width / 2.0 if k < num_sizes else \
+                    size_ratio_concat[0] * in_height / in_width * math.sqrt(size_ratio_concat[k + 1]) / 2.0
+                h = size_ratio_concat[k] / 2.0 if k < num_sizes else \
+                    size_ratio_concat[0] / math.sqrt(size_ratio_concat[k + 1]) / 2.0
+                count = i * in_width * (num_sizes + num_ratios - 1) + j * (num_sizes + num_ratios - 1) + k
+                np_out[0][count][0] = center_w - w
+                np_out[0][count][1] = center_h - h
+                np_out[0][count][2] = center_w + w
+                np_out[0][count][3] = center_h + h
+    if clip:
+        np_out = np.clip(np_out, 0, 1)
+
+    def check_device(device):
+        ctx = tvm.context(device, 0)
+        if not ctx.exist:
+            print("Skip because %s is not enabled" % device)
+            return
+        print("Running on target: %s" % device)
+        with tvm.target.create(device):
+            s = topi.generic.schedule_multibox_prior(out)
+
+        tvm_input_data = tvm.nd.array(input_data, ctx)
+        tvm_out = tvm.nd.array(np.zeros(oshape, dtype=dtype), ctx)
+        f = tvm.build(s, [data, out], device)
+        f(tvm_input_data, tvm_out)
+        np.testing.assert_allclose(tvm_out.asnumpy(), np_out, rtol=1e-4)
+
+    for device in ['llvm']:
+        check_device(device)
+
+
+def test_multibox_prior():
+    verify_multibox_prior((1, 3, 50, 50))
+    verify_multibox_prior((1, 3, 224, 224), sizes=(0.5, 0.25, 0.1), ratios=(1, 2, 0.5))
+    verify_multibox_prior((1, 32, 32, 32), sizes=(0.5, 0.25), ratios=(1, 2), steps=(2, 2), clip=True)
+
+
+def test_multibox_detection():
+    batch_size = 1
+    num_anchors = 3
+    num_classes = 3
+    cls_prob = tvm.placeholder((batch_size, num_anchors, num_classes), name="cls_prob")
+    loc_preds = tvm.placeholder((batch_size, num_anchors * 4), name="loc_preds")
+    anchors = tvm.placeholder((1, num_anchors, 4), name="anchors")
+    out = ssd.multibox_detection(cls_prob, loc_preds, anchors)
+
+    # Manually create test case
+    np_cls_prob = np.array([[[0.2, 0.5, 0.3], [0.25, 0.3, 0.45], [0.7, 0.1, 0.2]]])
+    np_loc_preds = np.array([[0.1, -0.2, 0.3, 0.2, 0.2, 0.4, 0.5, -0.3, 0.7, -0.2, -0.4, -0.8]])
+    np_anchors = np.array([[[-0.1, -0.1, 0.1, 0.1], [-0.2, -0.2, 0.2, 0.2], [1.2, 1.2, 1.5, 1.5]]])
+
+    expected_np_out = np.array([[[1, 0.69999999, 0, 0, 0.10818365, 0.10008108],
+                                 [0, 0.44999999, 1, 1, 1, 1],
+                                 [0, 0.30000001, 0, 0, 0.22903419, 0.20435292]]])
+
+    def check_device(device):
+        ctx = tvm.context(device, 0)
+        if not ctx.exist:
+            print("Skip because %s is not enabled" % device)
+            return
+        print("Running on target: %s" % device)
+        with tvm.target.create(device):
+            s = topi.generic.schedule_multibox_detection(out)
+
+        tvm_cls_prob = tvm.nd.array(np_cls_prob.astype(cls_prob.dtype), ctx)
+        tvm_loc_preds = tvm.nd.array(np_loc_preds.astype(loc_preds.dtype), ctx)
+        tvm_anchors = tvm.nd.array(np_anchors.astype(anchors.dtype), ctx)
+        tvm_out = tvm.nd.array(np.zeros((batch_size, num_anchors, 6)).astype(out.dtype), ctx)
+        f = tvm.build(s, [cls_prob, loc_preds, anchors, out], device)
+        f(tvm_cls_prob, tvm_loc_preds, tvm_anchors, tvm_out)
+        np.testing.assert_allclose(tvm_out.asnumpy(), expected_np_out, rtol=1e-4)
+
+    for device in ['llvm']:
+        check_device(device)
+
+
+if __name__ == "__main__":
+    test_nms()
+    test_multibox_prior()
+    test_multibox_detection()
\ No newline at end of file