Fixing support of PHIR's multi-assignment (#36)

* Fixing support of PHIR's multi-assignment

* bump version to 0.5.0.dev6

pyproject.toml

@@ -15,7 +15,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "quantum-pecos"
-version = "0.5.0.dev5"
+version = "0.5.0.dev6"
 authors = [
     {name = "The PECOS Developers"},
 ]

python/pecos/classical_interpreters/phir_classical_interpreter.py

@@ -260,11 +260,15 @@ def assign_int(self, cvar, val: int):
         self.cenv[cid] = cval
 
     def handle_cops(self, op):
+        """Handle the processing of classical operations."""
+
         if op.name == "=":
-            (arg,) = op.args
-            (rtn,) = op.returns
-            val = self.eval_expr(arg)
-            self.assign_int(rtn, val)
+            args = []
+            for a in op.args:
+                args.append(self.eval_expr(a))
+
+            for r, a in zip(op.returns, args):
+                self.assign_int(r, a)
 
         elif isinstance(op, pt.opt.FFCall):
             args = []

python/pecos/reps/pypmir/pypmir.py

@@ -155,9 +155,13 @@ def handle_op(cls, o: dict, p: PyPMIR) -> TypeOp:
 
     @classmethod
     def from_phir(cls, phir: dict) -> PyPMIR:
-        # TODO: Build nested instructions.
+        """Converts PHIR dict to PyPMIR object."""
 
-        p = PyPMIR(metadata=dict(phir["metadata"]))
+        p = PyPMIR(
+            metadata=dict(
+                phir.get("metadata", {}),
+            ),
+        )
 
         next_qvar_int = 0
 

tests/integration/test_phir_setting_cregs.py

@@ -0,0 +1,117 @@
+from pecos.engines.hybrid_engine import HybridEngine
+
+
+def test_setting_bits1():
+    phir = {
+        "format": "PHIR/JSON",
+        "version": "0.1.0",
+        "ops": [
+            {"data": "cvar_define", "data_type": "u32", "variable": "c", "size": 3},
+            # c[0], c[1], c[2] = True, False, True
+            {"cop": "=", "returns": [["c", 0], ["c", 1], ["c", 2]], "args": [True, False, True]},
+        ],
+    }
+
+    results = HybridEngine(qsim="stabilizer").run(program=phir, shots=5)
+
+    assert results["c"].count("101") == len(results["c"])
+
+
+def test_setting_bits2():
+    phir = {
+        "format": "PHIR/JSON",
+        "version": "0.1.0",
+        "ops": [
+            {"data": "cvar_define", "data_type": "u32", "variable": "c", "size": 3},
+            # c[0], c[1], c[2] = 0, 1, 1
+            {"cop": "=", "returns": [["c", 0], ["c", 1], ["c", 2]], "args": [0, 1, 1]},
+        ],
+    }
+
+    results = HybridEngine(qsim="stabilizer").run(program=phir, shots=5)
+
+    assert results["c"].count("110") == len(results["c"])
+
+
+def test_setting_cvar():
+    phir = {
+        "format": "PHIR/JSON",
+        "version": "0.1.0",
+        "ops": [
+            {"data": "cvar_define", "data_type": "u32", "variable": "a", "size": 3},
+            {"data": "cvar_define", "data_type": "u32", "variable": "b", "size": 3},
+            {"data": "cvar_define", "data_type": "u32", "variable": "c", "size": 3},
+            # a, b, c = 0, 1, 2
+            {"cop": "=", "returns": ["a", "b", "c"], "args": [0, 1, 2]},
+        ],
+    }
+
+    results = HybridEngine(qsim="stabilizer").run(program=phir, shots=5)
+
+    assert results["a"].count("000") == len(results["a"])
+    assert results["b"].count("001") == len(results["b"])
+    assert results["c"].count("010") == len(results["c"])
+
+
+def test_setting_expr():
+    phir = {
+        "format": "PHIR/JSON",
+        "version": "0.1.0",
+        "ops": [
+            {"data": "cvar_define", "data_type": "u32", "variable": "a", "size": 3},
+            {"data": "cvar_define", "data_type": "u32", "variable": "b", "size": 3},
+            {"data": "cvar_define", "data_type": "u32", "variable": "c", "size": 3},
+            # a, b, c = 0+1, a+1, c[1]+2
+            {
+                "cop": "=",
+                "returns": ["a", "b", "c"],
+                "args": [
+                    {"cop": "+", "args": [0, 1]},
+                    {"cop": "+", "args": ["a", 1]},
+                    {"cop": "+", "args": [["c", 1], 2]},
+                ],
+            },
+        ],
+    }
+
+    results = HybridEngine(qsim="stabilizer").run(program=phir, shots=5)
+
+    assert results["a"].count("001") == len(results["a"])
+    assert results["b"].count("001") == len(results["b"])
+    assert results["c"].count("010") == len(results["c"])
+
+
+def test_setting_mixed():
+    phir = {
+        "format": "PHIR/JSON",
+        "version": "0.1.0",
+        "ops": [
+            {"data": "cvar_define", "data_type": "u32", "variable": "a", "size": 3},
+            {"data": "cvar_define", "data_type": "u32", "variable": "b", "size": 3},
+            {"data": "cvar_define", "data_type": "u32", "variable": "c", "size": 3},
+            {"data": "cvar_define", "data_type": "u32", "variable": "d", "size": 3},
+            # a[0], b, c, d[2] = 1, 2, c[1]+2, a[0] + 1
+            {
+                "cop": "=",
+                "returns": [
+                    ["a", 0],
+                    "b",
+                    "c",
+                    ["d", 2],
+                ],
+                "args": [
+                    1,
+                    3,
+                    {"cop": "+", "args": [["c", 1], 2]},
+                    {"cop": "+", "args": [["a", 0], 1]},
+                ],
+            },
+        ],
+    }
+
+    results = HybridEngine(qsim="stabilizer").run(program=phir, shots=5)
+
+    assert results["a"].count("001") == len(results["a"])
+    assert results["b"].count("011") == len(results["b"])
+    assert results["c"].count("010") == len(results["c"])
+    assert results["d"].count("100") == len(results["d"])