From 3f32dcdef8bcdbbee72635fe47737cacfbc161ee Mon Sep 17 00:00:00 2001
From: Hugo Winbladh <hugwi268@student.liu.se>
Date: Sun, 27 Aug 2023 20:31:08 +0000
Subject: [PATCH] Add a sink operation to avoid dangling nodes
---
b_asic/core_operations.py | 43 +++++++++++++++++++++++++++++++++++-
test/test_core_operations.py | 15 +++++++++++++
2 files changed, 57 insertions(+), 1 deletion(-)
diff --git a/b_asic/core_operations.py b/b_asic/core_operations.py
index 17e762e7..e731a480 100644
--- a/b_asic/core_operations.py
+++ b/b_asic/core_operations.py
@@ -73,7 +73,6 @@ class Constant(AbstractOperation):
def __str__(self) -> str:
return f"{self.value}"
-
class Addition(AbstractOperation):
"""
Binary addition operation.
@@ -1263,3 +1262,45 @@ class Shift(AbstractOperation):
if not isinstance(value, int):
raise TypeError("value must be an int")
self.set_param("value", value)
+
+class Sink(AbstractOperation):
+ r"""
+ Sink operation.
+
+ Used for ignoring the output from another operation to avoid dangling output nodes.
+
+ Parameters
+ ==========
+
+ name : Name, optional
+ Operation name.
+ """
+
+ _execution_time = 0
+ is_linear = True
+
+ def __init__(self, name: Name = ""):
+ """Construct a Sink operation."""
+ super().__init__(
+ input_count=1,
+ output_count=0,
+ name=name,
+ latency_offsets={"in0": 0},
+ )
+
+ @classmethod
+ def type_name(cls) -> TypeName:
+ return TypeName("sink")
+
+ def evaluate(self):
+ raise NotImplementedError
+
+ @property
+ def latency(self) -> int:
+ return self.latency_offsets["in0"]
+
+ def __repr__(self) -> str:
+ return "Sink()"
+
+ def __str__(self) -> str:
+ return "sink"
diff --git a/test/test_core_operations.py b/test/test_core_operations.py
index 40f15f2f..002e38c9 100644
--- a/test/test_core_operations.py
+++ b/test/test_core_operations.py
@@ -20,6 +20,8 @@ from b_asic import (
SquareRoot,
Subtraction,
SymmetricTwoportAdaptor,
+ Sink,
+ SFG,
)
@@ -404,3 +406,16 @@ class TestDepends:
bfly1 = Butterfly()
assert set(bfly1.inputs_required_for_output(0)) == {0, 1}
assert set(bfly1.inputs_required_for_output(1)) == {0, 1}
+
+class TestSink:
+ def test_create_sfg_with_sink(self):
+ bfly = Butterfly()
+ sfg = bfly.to_sfg()
+ s = Sink()
+ sfg1 = sfg.replace_operation(s, "out0")
+ sfg2 = SFG(sfg1.input_operations, sfg1.output_operations[1:])
+
+ assert sfg2.output_count == 1
+ assert sfg2.input_count == 2
+
+ assert sfg.evaluate_output(1, [0,1]) == sfg2.evaluate_output(0, [0,1])
--
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