Avoid unneeded nesting

src/onnx/parse_if.cpp

@@ -115,76 +115,78 @@ struct parse_if : op_parser<parse_if>
                                else_out_shape.type_string());
             }
 
-            if(not then_out_shape.dynamic() and not else_out_shape.dynamic())
+            if(then_out_shape.dynamic() or else_out_shape.dynamic())
             {
-                auto then_lens = then_out_shape.lens();
-                auto else_lens = else_out_shape.lens();
+                continue;
+            }
 
-                // Throw error if both branches have zero output shapes. Not possible for static
-                // inputs
-                if(then_lens.empty() and else_lens.empty())
-                {
-                    throw_shapes();
-                }
+            auto then_lens = then_out_shape.lens();
+            auto else_lens = else_out_shape.lens();
 
-                auto handle_empty_branch = [](module_ref& mdl, int index, const shape& out_shape) {
-                    shape gen_shape(shape(out_shape.type(), {1}, {0}));
-                    auto literal_ins =
-                        mdl->insert_literal(std::prev(mdl->end()), literal(gen_shape, {0}));
-                    auto unsqueeze_ins = mdl->insert_instruction(
-                        std::prev(mdl->end()),
-                        make_op("scalar", {{"scalar_bcst_dims", out_shape.lens()}}),
-                        literal_ins);
-                    auto broad_ins = mdl->insert_instruction(
-                        std::prev(mdl->end()),
-                        make_op("multibroadcast", {{"out_lens", out_shape.lens()}}),
-                        unsqueeze_ins);
-                    auto contig_out = mdl->insert_instruction(
-                        std::prev(mdl->end()), make_op("contiguous"), broad_ins);
-                    mdl->replace_instruction(std::prev(mdl->end())->inputs().at(index), contig_out);
-                    return out_shape.lens();
-                };
-
-                // Handle one empty branch by setting output identical to the other
-                // need to update the then_shape before we do further checks
-                if(then_lens.empty())
-                {
-                    then_lens = handle_empty_branch(then_mdl, i, else_out_shape);
-                }
-                else if(else_lens.empty())
+            // Throw error if both branches have zero output shapes. Not possible for static
+            // inputs
+            if(then_lens.empty() and else_lens.empty())
+            {
+                throw_shapes();
+            }
+
+            auto handle_empty_branch = [](module_ref& mdl, int index, const shape& out_shape) {
+                shape gen_shape(shape(out_shape.type(), {1}, {0}));
+                auto literal_ins =
+                    mdl->insert_literal(std::prev(mdl->end()), literal(gen_shape, {0}));
+                auto unsqueeze_ins = mdl->insert_instruction(
+                    std::prev(mdl->end()),
+                    make_op("scalar", {{"scalar_bcst_dims", out_shape.lens()}}),
+                    literal_ins);
+                auto broad_ins = mdl->insert_instruction(
+                    std::prev(mdl->end()),
+                    make_op("multibroadcast", {{"out_lens", out_shape.lens()}}),
+                    unsqueeze_ins);
+                auto contig_out = mdl->insert_instruction(
+                    std::prev(mdl->end()), make_op("contiguous"), broad_ins);
+                mdl->replace_instruction(std::prev(mdl->end())->inputs().at(index), contig_out);
+                return out_shape.lens();
+            };
+
+            // Handle one empty branch by setting output identical to the other
+            // need to update the then_shape before we do further checks
+            if(then_lens.empty())
+            {
+                then_lens = handle_empty_branch(then_mdl, i, else_out_shape);
+            }
+            else if(else_lens.empty())
+            {
+                else_lens = handle_empty_branch(else_mdl, i, then_out_shape);
+            }
+
+            // check equivalent length dims, and (x1,x2,.., xn, 1) == (x1,x2,..,xn)
+            int rank_delta = abs((static_cast<int>(then_lens.size() - else_lens.size())));
+
+            if(rank_delta == 1)
+            {
+                // make sure dims are equivalent in static shapes
+                if(not all_but_last_dims_equal(then_lens, else_lens))
                 {
-                    else_lens = handle_empty_branch(else_mdl, i, then_out_shape);
+                    throw_shapes();
                 }
 
-                // check equivalent length dims, and (x1,x2,.., xn, 1) == (x1,x2,..,xn)
-                int rank_delta = abs((static_cast<int>(then_lens.size() - else_lens.size())));
+                auto last_then = then_lens.back();
+                auto last_else = else_lens.back();
 
-                if(rank_delta == 1)
+                // Find which dim to unsqueeze
+                if((then_lens.size() < else_lens.size()) && (last_else == 1))
                 {
-                    // make sure dims are equivalent in static shapes
-                    if(not all_but_last_dims_equal(then_lens, else_lens))
-                    {
-                        throw_shapes();
-                    }
-
-                    auto last_then = then_lens.back();
-                    auto last_else = else_lens.back();
-
-                    // Find which dim to unsqueeze
-                    if((then_lens.size() < else_lens.size()) && (last_else == 1))
-                    {
-                        unsqueeze_last_op(then_mdl, i, else_lens);
-                    }
-                    else if((then_lens.size() > else_lens.size()) && (last_then == 1))
-                    {
-                        unsqueeze_last_op(else_mdl, i, then_lens);
-                    }
+                    unsqueeze_last_op(then_mdl, i, else_lens);
                 }
-                else if(rank_delta > 1)
+                else if((then_lens.size() > else_lens.size()) && (last_then == 1))
                 {
-                    throw_shapes();
+                    unsqueeze_last_op(else_mdl, i, then_lens);
                 }
             }
+            else if(rank_delta > 1)
+            {
+                throw_shapes();
+            }
         }
 
         auto if_ret = info.add_instruction(make_op("if"), args, {then_mdl, else_mdl});