feat(frontend-python): Enable multi output programs

frontends/concrete-python/concrete/fhe/compilation/compiler.py

@@ -447,14 +447,6 @@ def compile(
             self._evaluate("Compiling", inputset)
             assert self.graph is not None
 
-            if len(self.graph.output_nodes) > 1:
-                fmtd_graph = self.graph.format(
-                    highlighted_result=["multiple outputs are not supported"],
-                    show_bounds=False,
-                )
-                message = "Function you are trying to compile cannot be compiled\n\n" + fmtd_graph
-                raise RuntimeError(message)
-
             # in-memory MLIR module
             mlir_context = self.compilation_context.mlir_context()
             mlir_module = GraphConverter().convert(self.graph, self.configuration, mlir_context)

frontends/concrete-python/tests/compilation/test_compiler.py

@@ -347,68 +347,6 @@ def g(x):
     )
 
 
-def test_direct_circuit_multi_output(helpers):
-    """
-    Test `run` method of `Circuit` class with bad parameters.
-    """
-
-    configuration = helpers.configuration()
-    with pytest.raises(RuntimeError) as excinfo:
-
-        @fhe.circuit({"x": "encrypted", "y": "encrypted"}, configuration)
-        def f(x: fhe.uint4, y: fhe.uint4):
-            return x, y
-
-    assert (
-        str(excinfo.value)
-        == """\
-Function you are trying to compile cannot be compiled
-
-%0 = x        # EncryptedScalar<uint4>
-%1 = y        # EncryptedScalar<uint4>
-return %0, %1
-^^^^^^^^^^^^^ multiple outputs are not supported\
-"""
-    )
-
-
-def test_circuit_multi_output(helpers):
-    """
-    Test `run` method of `Circuit` class with bad parameters.
-    """
-
-    configuration = helpers.configuration()
-
-    @fhe.compiler({"x": "encrypted", "y": "encrypted"})
-    def f(x, y):
-        return x, y
-
-    inputset = [(0, 0), (15, 15)]
-    graph = f.trace(inputset)
-    assert (
-        graph.format()
-        == """\
-%0 = x        # EncryptedScalar<uint4>        ∈ [0, 15]
-%1 = y        # EncryptedScalar<uint4>        ∈ [0, 15]
-return %0, %1\
-"""
-    )
-
-    with pytest.raises(RuntimeError) as excinfo:
-        f.compile(inputset, configuration)
-    assert (
-        str(excinfo.value)
-        == """\
-Function you are trying to compile cannot be compiled
-
-%0 = x        # EncryptedScalar<uint4>
-%1 = y        # EncryptedScalar<uint4>
-return %0, %1
-^^^^^^^^^^^^^ multiple outputs are not supported\
-"""
-    )
-
-
 def test_compiler_compile_with_single_tuple_inputset(helpers):
     """
     Test compiling a single argument function with an inputset made of single element tuples.

frontends/concrete-python/tests/execution/test_multi_output.py

@@ -0,0 +1,47 @@
+"""
+Tests of execution with multiple outputs.
+"""
+
+import pytest
+
+from concrete import fhe
+
+
+@pytest.mark.parametrize(
+    "function,parameters",
+    [
+        pytest.param(
+            lambda x: (x * 2, x - 2),
+            {
+                "x": {"range": [0, 10], "status": "encrypted"},
+            },
+        ),
+        pytest.param(
+            lambda x, y: (x * 2, y - 2),
+            {
+                "x": {"range": [0, 2], "status": "encrypted"},
+                "y": {"range": [0, 15], "status": "encrypted"},
+            },
+        ),
+        pytest.param(
+            lambda x, y: (x * 2, y - 2),
+            {
+                "x": {"range": [0, 2], "shape": (2, 3), "status": "encrypted"},
+                "y": {"range": [0, 15], "status": "encrypted"},
+            },
+        ),
+    ],
+)
+def test_multi_output(function, parameters, helpers):
+    """
+    Test functions with multiple outputs.
+    """
+
+    parameter_encryption_statuses = helpers.generate_encryption_statuses(parameters)
+    configuration = helpers.configuration()
+    compiler = fhe.Compiler(function, parameter_encryption_statuses)
+    inputset = helpers.generate_inputset(parameters)
+    circuit = compiler.compile(inputset, configuration)
+
+    sample = helpers.generate_sample(parameters)
+    helpers.check_execution(circuit, function, sample)