From 9d274a0826b0bc6941d7dc70c6bfe3e9e332887a Mon Sep 17 00:00:00 2001 From: whitequark Date: Wed, 19 Feb 2020 01:21:00 +0000 Subject: [PATCH] back.pysim: fix RHS codegen for Cat() and Repl(..., 0). Fixes #325. --- nmigen/back/pysim.py | 8 ++++++-- nmigen/test/test_sim.py | 12 ++++++++++++ 2 files changed, 18 insertions(+), 2 deletions(-) diff --git a/nmigen/back/pysim.py b/nmigen/back/pysim.py index 7ddbde2..5d599a3 100644 --- a/nmigen/back/pysim.py +++ b/nmigen/back/pysim.py @@ -492,7 +492,9 @@ class _RHSValueCompiler(_ValueCompiler): part_mask = (1 << len(part)) - 1 gen_parts.append(f"(({self(part)} & {part_mask}) << {offset})") offset += len(part) - return f"({' | '.join(gen_parts)})" + if gen_parts: + return f"({' | '.join(gen_parts)})" + return f"0" def on_Repl(self, value): part_mask = (1 << len(value.value)) - 1 @@ -502,7 +504,9 @@ class _RHSValueCompiler(_ValueCompiler): for _ in range(value.count): gen_parts.append(f"({gen_part} << {offset})") offset += len(value.value) - return f"({' | '.join(gen_parts)})" + if gen_parts: + return f"({' | '.join(gen_parts)})" + return f"0" def on_ArrayProxy(self, value): index_mask = (1 << len(value.index)) - 1 diff --git a/nmigen/test/test_sim.py b/nmigen/test/test_sim.py index 932d0f9..d3585a4 100644 --- a/nmigen/test/test_sim.py +++ b/nmigen/test/test_sim.py @@ -712,3 +712,15 @@ class SimulatorIntegrationTestCase(FHDLTestCase): with sim.write_vcd(open(os.path.devnull, "wt")): with sim.write_vcd(open(os.path.devnull, "wt")): pass + + +class SimulatorRegressionTestCase(FHDLTestCase): + def test_bug_325(self): + dut = Module() + dut.d.comb += Signal().eq(Cat()) + Simulator(dut).run() + + def test_bug_325_bis(self): + dut = Module() + dut.d.comb += Signal().eq(Repl(Const(1), 0)) + Simulator(dut).run() -- 2.30.2