Add examples dir

examples/test_simple_alu.py

@@ -0,0 +1,93 @@
+import magma as m
+import mantle
+import operator
+import fault
+import pytest
+from hwtypes import BitVector
+import os
+
+
+class ConfigReg(m.Circuit):
+    IO = ["D", m.In(m.Bits[2]), "Q", m.Out(m.Bits[2])] + \
+        m.ClockInterface(has_ce=True)
+
+    @classmethod
+    def definition(io):
+        reg = mantle.Register(2, has_ce=True, name="conf_reg")
+        io.Q <= reg(io.D, CE=io.CE)
+
+
+class SimpleALU(m.Circuit):
+    IO = ["a", m.In(m.UInt[16]),
+          "b", m.In(m.UInt[16]),
+          "c", m.Out(m.UInt[16]),
+          "config_data", m.In(m.Bits[2]),
+          "config_en", m.In(m.Enable),
+          ] + m.ClockInterface()
+
+    @classmethod
+    def definition(io):
+        opcode = ConfigReg(name="config_reg")(io.config_data, CE=io.config_en)
+        io.c <= mantle.mux(
+            [io.a + io.b, io.a - io.b, io.a * io.b, io.a ^ io.b], opcode)
+
+
+def test_simple_alu():
+    ops = [operator.add, operator.sub, operator.mul, operator.xor]
+    tester = fault.Tester(SimpleALU, SimpleALU.CLK)
+    tester.circuit.CLK = 0
+    tester.circuit.config_en = 1
+    for i in range(0, 4):
+        tester.circuit.config_data = i
+        tester.step(2)
+        tester.circuit.a = 3
+        tester.circuit.b = 2
+        tester.eval()
+        tester.circuit.c.expect(ops[i](3, 2))
+
+    tester.compile_and_run("verilator", flags=["-Wno-fatal"], directory="build")
+
+
+@pytest.mark.parametrize("opcode, op",
+                         enumerate(["add", "sub", "mul", "floordiv"]))
+def test_simple_alu_parametrized(opcode, op):
+    op = getattr(operator, op)
+    tester = fault.Tester(SimpleALU, SimpleALU.CLK)
+    tester.circuit.CLK = 0
+    tester.circuit.config_en = 1
+    tester.circuit.config_data = opcode
+    tester.step(4)
+    tester.circuit.a = 3
+    tester.circuit.b = 2
+    tester.eval()
+    tester.circuit.c.expect(op(BitVector[16](3), BitVector[16](2)))
+
+    os.system("rm -r build/*")
+    tester.compile_and_run("verilator", flags=["-Wno-fatal"], directory="build")
+
+
+@pytest.mark.parametrize("target", ["verilator", "cosa"])
+def test_simple_alu_assume_guarantee(target):
+    tester = fault.SymbolicTester(SimpleALU, SimpleALU.CLK, num_tests=100)
+    tester.circuit.config_en = 1
+    tester.circuit.config_data = 0
+    tester.step(2)
+    tester.circuit.config_en = 0
+    tester.step(2)
+    if target == "verilator":
+        # NOTE: Currently the cosa backend does not support the expect action
+        tester.circuit.config_reg.Q.expect(0)
+    tester.circuit.a.assume(lambda a: a < BitVector(32768, 16))
+    tester.circuit.b.assume(lambda b: b < BitVector(32768, 16))
+    # tester.circuit.b.assume(lambda b: b >= BitVector(32768, 16))
+
+    tester.circuit.c.guarantee(lambda a, b, c: (c >= a) and (c >= b))
+    kwargs = {}
+    if target == "verilator":
+        kwargs["flags"] = ["-Wno-fatal"]
+        kwargs["magma_opts"] = {"verilator_debug": True}
+    elif target == "cosa":
+        kwargs["magma_opts"] = {"passes": ["rungenerators", "flatten",
+                                           "cullgraph"]}
+    os.system("rm -r build/*")
+    tester.compile_and_run(target, directory="build", **kwargs)