Fix accuracy bug when vectorizing slices

src/targets/gpu/compile_gen.cpp

@@ -61,12 +61,17 @@ vectorize vectorize::elements(std::size_t axis, const std::vector<shape>& inputs
                    [&](const auto& input) -> std::size_t {
                        auto stride = input.strides()[axis];
                        auto len    = input.lens()[axis];
-                       if(stride != 0 and stride != 1)
+                       if(not contains({0, 1}, stride))
                            return 1;
                        if(len == 1 and input.elements() > sizes.front())
                            return sizes.front();
                        auto it = std::find_if(
-                           sizes.begin(), sizes.end(), [&](auto i) { return (len % i) == 0; });
+                           sizes.begin(), sizes.end(), [&](auto vsize) {
+                            // The len is divisible by the size and all the strides are divisible by the size
+                            return (len % vsize) == 0 and std::all_of(input.strides().begin(), input.strides().end(), [&](auto i) {
+                                return contains({0, 1}, i) or i % vsize == 0;
+                            });
+                        });
                        if(it != sizes.end())
                            return *it;
                        return 1;