Fix single dim

src/reduce_dims.cpp

@@ -38,7 +38,7 @@ bool reduce_dim(std::vector<shape>& shapes, std::size_t n)
 void reduce_dim1(std::vector<shape>& shapes)
 {
     if(std::any_of(
-           shapes.begin(), shapes.end(), [&](const auto& s) { return s.lens().back() != 1; }))
+           shapes.begin(), shapes.end(), [&](const auto& s) { return s.lens().size() < 2 or s.lens().back() != 1; }))
         return;
     for(auto& s : shapes)
     {

test/reduce_dims.cpp

@@ -125,6 +125,13 @@ TEST_CASE(non_packed_empty2)
     EXPECT(eshapes == rshapes);
 }
 
+TEST_CASE(single_dim)
+{
+    std::vector<migraphx::shape> ishapes = {make_shape({1}, {1})};
+    auto rshapes                         = migraphx::reduce_dims(ishapes);
+    EXPECT(ishapes == rshapes);
+}
+
 TEST_CASE(empty)
 {
     auto rshapes = migraphx::reduce_dims({});