Add python bindings for RDom::where

python_bindings/python/RDom.cpp

@@ -148,7 +148,6 @@ h::RDom *RDom_constructor4(h::Expr min0, h::Expr extent0,
 void defineRDom()
 {
     using Halide::RDom;
-
 
     defineRVar();
 
@@ -218,7 +217,19 @@ void defineRDom()
                  "Compare two reduction domains for equality of reference")
             .def("dimensions", &RDom::dimensions, p::arg("self"),
                  "Get the dimensionality of a reduction domain")
-
+            .def("where", &RDom::where, p::args("self", "predicate"),
+                  "Add a predicate to the RDom. An RDom may have multiple"
+                  "predicates associated with it. An update definition that uses"
+                  "an RDom only iterates over the subset points in the domain for"
+                  "which all of its predicates are true. The predicate expression"
+                  "obeys the same rules as the expressions used on the"
+                  "right-hand-side of the corresponding update definition. It may"
+                  "refer to the RDom's variables and free variables in the Func's"
+                  "update definition. It may include calls to other Funcs, or make"
+                  "recursive calls to the same Func. This permits iteration over"
+                  "non-rectangular domains, or domains with sizes that vary with"
+                  "some free variable, or domains with shapes determined by some"
+                  "other Func. ")
             //"Get at one of the dimensions of the reduction domain"
             //EXPORT RVar operator[](int) const;
 

python_bindings/tests/test_rdom.py

@@ -0,0 +1,33 @@
+#!/usr/bin/python3
+
+import halide as h
+
+def test_rdom():
+    x = h.Var("x")
+    y = h.Var("y")
+
+    diagonal = h.Func("diagonal")
+    diagonal[x, y] = 1
+
+    domain_width = 10
+    domain_height = 10
+
+    r = h.RDom(0, domain_width, 0, domain_height)
+    r.where(r.x <= r.y)
+
+    diagonal[r.x, r.y] = 2
+    output = diagonal.realize(domain_width, domain_height)
+    output = h.Image(h.Int(32), output)
+
+    for iy in range(domain_height):
+        for ix in range(domain_width):
+            if ix <= iy:
+                assert output(ix, iy) == 2
+            else:
+                assert output(ix, iy) == 1
+
+    print("Success!")
+    return 0
+
+if __name__ == "__main__":
+    test_rdom()