Expose estimate resources as dict (#3662)

* Adding an api to expose gateCounts as a dictionary

* adding a doc comment for the method

* Keeping track of resources when instructions are appended

* Updating map to take controls into account

* adding a test for control gates

* reverting the functionality for count

Signed-off-by: Sachin Pisal <[email protected]>

* Using instructions map to expose gateCounts

* initializing nControls to 0

---------

Signed-off-by: Sachin Pisal <[email protected]>

Author: sacpis

python/runtime/common/py_Resources.cpp

@@ -55,6 +55,10 @@ This includes all gate counts.)#")
           },
           "Return a string of the raw resource counts that are stored in "
           "`self`.\n")
+      .def(
+          "to_dict", [](Resources &self) { return self.gateCounts(); },
+          "Return a dictionary of the raw resource counts that are stored in "
+          "`self`.\n")
       .def("clear", &Resources::clear, "Clear out all metadata from `self`.\n");
 }
 

python/tests/backends/test_resource_counter.py

@@ -46,6 +46,50 @@ def mykernel():
     assert counts.count("s") == 1
     assert counts.count("t") == 1
 
+    d = counts.to_dict()
+    assert d["rx"] == 1
+    assert d["ry"] == 1
+    assert d["rz"] == 1
+    assert d["h"] == 1
+    assert d["x"] == 1
+    assert d["y"] == 1
+    assert d["z"] == 1
+    assert d["s"] == 1
+    assert d["t"] == 1
+
+
+def test_control_gates_resources():
+
+    @cudaq.kernel
+    def mykernel():
+        q = cudaq.qvector(3)
+        x(q[0])
+        x.ctrl(q[0], q[1])
+        x.ctrl([q[0], q[1]], q[2])
+        h(q[0])
+        h.ctrl(q[0], q[1])
+
+    counts = cudaq.estimate_resources(mykernel)
+
+    assert counts.count_controls("x", 0) == 1
+    assert counts.count_controls("x", 1) == 1
+    assert counts.count_controls("x", 2) == 1
+
+    assert counts.count_controls("h", 0) == 1
+    assert counts.count_controls("h", 1) == 1
+
+    assert counts.count() == 5
+
+    d = counts.to_dict()
+    assert isinstance(d, dict)
+
+    assert d["x"] == 1
+    assert d["h"] == 1
+
+    assert d["cx"] == 1
+    assert d["ccx"] == 1
+    assert d["ch"] == 1
+
 
 def test_choice_function():
 
@@ -73,6 +117,14 @@ def choice():
     assert counts2.count("h") == 1
     assert counts2.count("x") == 1
 
+    d1 = counts1.to_dict()
+    d2 = counts2.to_dict()
+    assert isinstance(d1, dict)
+    assert isinstance(d2, dict)
+    assert d1["h"] == 1
+    assert d2["h"] == 1
+    assert d2["x"] == 1
+
     cudaq.set_target("quantinuum", emulate=True)
     counts1 = cudaq.estimate_resources(mykernel)
     counts2 = cudaq.estimate_resources(mykernel, choice=choice)
@@ -81,6 +133,12 @@ def choice():
     assert counts2.count("h") == 1
     assert counts2.count("x") == 1
 
+    d1 = counts1.to_dict()
+    d2 = counts2.to_dict()
+    assert d1["h"] == 1
+    assert d2["h"] == 1
+    assert d2["x"] == 1
+
 
 def test_choice_function():
 
@@ -162,11 +220,21 @@ def caller(n: int, angles: list[float]):
     assert counts.count("rx") == 3
     assert counts.count("h") == 1
 
+    d = counts.to_dict()
+    assert isinstance(d, dict)
+    assert d["rx"] == 3
+    assert d["h"] == 1
+
     cudaq.set_target("qci", emulate=True)
     counts = cudaq.estimate_resources(caller, 3, [4.0, 5.0, 6.0])
     assert counts.count("rx") == 3
     assert counts.count("h") == 1
 
+    d = counts.to_dict()
+    assert isinstance(d, dict)
+    assert d["rx"] == 3
+    assert d["h"] == 1
+
 
 # leave for gdb debugging
 if __name__ == "__main__":

runtime/common/Resources.cpp

@@ -77,7 +77,7 @@ void Resources::dump(std::ostream &os) const {
   os << "\n  ";
   std::size_t counter = 0;
   for (auto &result : instructions) {
-    std::string gatestr("c", result.first.nControls);
+    std::string gatestr(result.first.nControls, 'c');
     gatestr += result.first.name;
     os << gatestr << " :  " << result.second;
     bool isLast = counter == instructions.size() - 1;
@@ -96,4 +96,14 @@ void Resources::clear() {
 }
 
 void Resources::addQubit() { numQubits++; }
+
+std::unordered_map<std::string, std::size_t> Resources::gateCounts() const {
+  std::unordered_map<std::string, std::size_t> gateCounts;
+  for (auto &result : instructions) {
+    std::string gatestr(result.first.nControls, 'c');
+    gatestr += result.first.name;
+    gateCounts[gatestr] = result.second;
+  }
+  return gateCounts;
+}
 } // namespace cudaq

runtime/common/Resources.h

@@ -39,7 +39,7 @@ class Resources {
     /// @brief The number of controls
     std::size_t nControls;
 
-    Instruction(const std::string &n) : name(n) {}
+    Instruction(const std::string &n) : name(n), nControls(0) {}
 
     /// @brief The constructor
     Instruction(const std::string &n, const size_t c) : name(n), nControls(c) {}
@@ -82,6 +82,9 @@ class Resources {
   /// @brief Register the usage of an additional qubit
   void addQubit();
 
+  /// @brief Returns a dictionary mapping gate names to counts
+  std::unordered_map<std::string, std::size_t> gateCounts() const;
+
 private:
   /// @brief Map of Instructions in the current kernel to the
   /// number of times the Instruction is used.