Add dynamic shape constructor

Constructs a dynamic shape from three vectors of lengths,
the minimums, maximums, and optimals

src/include/migraphx/op/convolution.hpp

@@ -176,11 +176,7 @@ struct convolution
             auto min_spatial_dims = calc_conv_lens(x_shape.min_lens(), w_shape.max_lens());
             auto max_spatial_dims = calc_conv_lens(x_shape.max_lens(), w_shape.min_lens());
             auto opt_spatial_dims = calc_conv_lens(x_shape.opt_lens(), w_shape.opt_lens());
-            for(size_t i = 0; i < num_spatial_dims; ++i)
-            {
-                output_dyn_dims.push_back(shape::dynamic_dimension{
-                    min_spatial_dims[i], max_spatial_dims[i], opt_spatial_dims[i]});
-            }
+            return shape{x_shape.type(), min_spatial_dims, max_spatial_dims, opt_spatial_dims};
         }
         return shape{x_shape.type(), output_dyn_dims};
     }

src/include/migraphx/shape.hpp

@@ -115,6 +115,12 @@ struct shape
 
     shape(type_t t, std::vector<dynamic_dimension> dims);
 
+    // Construct a dynamic shape from three sets of lengths (of the same rank)
+    shape(type_t t,
+          std::vector<std::size_t> mins,
+          std::vector<std::size_t> maxes,
+          std::vector<std::size_t> opts);
+
     template <class Range>
     shape(type_t t, const Range& l) : shape(t, std::vector<std::size_t>(l.begin(), l.end()))
     {

src/shape.cpp

@@ -71,6 +71,19 @@ struct shape_impl
     {
     }
 
+    shape_impl(shape::type_t t,
+               std::vector<std::size_t> mins,
+               std::vector<std::size_t> maxes,
+               std::vector<std::size_t> opts)
+        : m_type(t)
+    {
+        assert(mins.size() == maxes.size() and maxes.size() == opts.size());
+        for(size_t i = 0; i < mins.size(); ++i)
+        {
+            m_dyn_dims.push_back(shape::dynamic_dimension{mins[i], maxes[i], opts[i]});
+        }
+    }
+
     shape_impl(const std::vector<shape>& subs) : m_type(shape::tuple_type), m_shapes(subs) {}
 
     shape::type_t m_type;