Multi output primitives (#330)

* Multi-output primitives

---------

Co-authored-by: Angelos Katharopoulos <a_katharopoulos@apple.com>

benchmarks/cpp/single_ops.cpp

@@ -233,6 +233,20 @@ void time_gather_scatter() {
   TIME(single_element_add);
 }
 
+void time_divmod() {
+  auto a = random::normal({1000});
+  auto b = random::normal({1000});
+  eval({a, b});
+
+  auto divmod_fused = [&a, &b]() { return divmod(a, b); };
+  TIME(divmod_fused);
+
+  auto divmod_separate = [&a, &b]() {
+    return std::vector<array>{floor_divide(a, b), remainder(a, b)};
+  };
+  TIME(divmod_separate);
+}
+
 int main() {
   std::cout << "Benchmarks for " << default_device() << std::endl;
   time_creation_ops();
@@ -246,4 +260,5 @@ int main() {
   time_matmul();
   time_reductions();
   time_gather_scatter();
+  time_divmod();
 }