Add tile operation

Author: ZihengJiang

include/tvm/schedule.h

@@ -100,6 +100,9 @@ class Schedule : public NodeRef {
    * \return reference to self.
    */
   Schedule& reorder(const Array<IterVar>& order);   // NOLINT(*)
+  Schedule& tile(IterVar x_parent, IterVar y_parent, IterVar* p_x_outer,
+                 IterVar* p_y_outer, IterVar* p_x_inner, IterVar* p_y_inner,
+                 Expr x_factor, Expr y_factor);   // NOLINT(*)
 };
 
 /*!

python/tvm/schedule.py

@@ -107,3 +107,8 @@ def reorder(self, *args):
             The order to be ordered
         """
         _function_internal._ScheduleReorder(self, args)
+
+    def tile(self, x_parent, y_parent, x_factor, y_factor):
+        x_outer, y_outer, x_inner, y_inner = _function_internal._ScheduleTile(
+            self, x_parent, y_parent, x_factor, y_factor)
+        return x_outer, y_outer, x_inner, y_inner

src/c_api/c_api_lang.cc

@@ -151,5 +151,13 @@ TVM_REGISTER_API(_ScheduleReorder)
         .reorder(args.at(1));
   });
 
+TVM_REGISTER_API(_ScheduleTile)
+  .set_body([](const ArgStack& args, RetValue *ret) {
+    IterVar x_outer, y_outer, x_inner, y_inner;
+    args.at(0).operator Schedule()
+        .tile(args.at(1), args.at(2), &x_outer, &y_outer,
+              &x_inner, &y_inner, args.at(3), args.at(4));
+    *ret = Array<IterVar>({x_outer, y_outer, x_inner, y_inner});
+  });
 
 }  // namespace tvm

src/lang/schedule.cc

@@ -148,6 +148,16 @@ Schedule& Schedule::reorder(const Array<IterVar>& order) {  // NOLINT(*)
   return *this;
 }
 
+Schedule& Schedule::tile(IterVar x_parent, IterVar y_parent, IterVar* p_x_outer,
+                         IterVar* p_y_outer, IterVar* p_x_inner, IterVar* p_y_inner,
+                         Expr x_factor, Expr y_factor) { // NOLINT(*)
+
+  split(x_parent, p_x_outer, p_x_inner, x_factor);
+  split(y_parent, p_y_outer, p_y_inner, y_factor);
+  reorder(Array<IterVar>({*p_x_inner, *p_y_inner, *p_x_outer, *p_y_outer}));
+  return *this;
+}
+
 IterVarRelation SplitNode::make(
     IterVar parent, IterVar outer,
     IterVar inner, Expr factor) {

tests/python/test_schedule.py

@@ -34,8 +34,18 @@ def test_reorder():
     sch_T.reorder(*order)
     assert tuple(sch_T.leaf_iter_vars) == order
 
+def test_tile():
+    m = tvm.Var('m')
+    n = tvm.Var('n')
+    A = tvm.placeholder((m, n), name='A')
+    T = tvm.compute((m, n), lambda i, j: A[i, j])
+
+    sch_T = tvm.Schedule(T.op, scope="shared")
+    xo, yo, xi, yi = sch_T.tile(T.op.dim_var[0], T.op.dim_var[1], x_factor=10, y_factor=5)
+    assert tuple(sch_T.leaf_iter_vars) == (xi, yi, xo, yo)
 
 if __name__ == "__main__":
     test_schedule_create()
     test_reorder()
+    test_tile()