base: Add GTest to SatCounter

Add a GTest to the SatCounter class.

Change-Id: Iaf1b18db9fe8d7fe32e0e40c7947dcd1fd6cc33b
Signed-off-by: Daniel <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/17994
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

src/base/SConscript

@@ -88,6 +88,7 @@ GTest('addr_range_map.test', 'addr_range_map.test.cc')
 GTest('bitunion.test', 'bitunion.test.cc')
 GTest('circlebuf.test', 'circlebuf.test.cc')
 GTest('circular_queue.test', 'circular_queue.test.cc')
+GTest('sat_counter.test', 'sat_counter.test.cc')
 
 DebugFlag('Annotate', "State machine annotation debugging")
 DebugFlag('AnnotateQ', "State machine annotation queue debugging")

src/base/sat_counter.test.cc

@@ -0,0 +1,131 @@
+/*
+ * Copyright (c) 2019 Inria
+ * All rights reserved
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Daniel Carvalho
+ */
+
+#include <gtest/gtest.h>
+
+#include "base/sat_counter.hh"
+
+/**
+ * Test if the maximum value is indeed the maximum value reachable.
+ */
+TEST(SatCounterTest, MaximumValue)
+{
+    const unsigned bits = 3;
+    const unsigned max_value = (1 << bits) - 1;
+    SatCounter counter(bits);
+
+    for (int i = 0; i < 2*max_value; i++) {
+        counter++;
+    }
+
+    ASSERT_EQ(counter, max_value);
+}
+
+/**
+ * Test if the minimum value is indeed the mimimum value reachable.
+ */
+TEST(SatCounterTest, MinimumValue)
+{
+    const unsigned bits = 3;
+    SatCounter counter(bits);
+
+    for (int i = 0; i < 2; i++) {
+        counter--;
+    }
+
+    ASSERT_EQ(counter, 0);
+}
+
+/**
+ * Test initializing the counter with a value, updating it and then resetting.
+ */
+TEST(SatCounterTest, InitialValue)
+{
+    const unsigned bits = 3;
+    const unsigned initial_value = 4;
+    SatCounter counter(bits, initial_value);
+    ASSERT_EQ(counter, initial_value);
+    counter++;
+    counter.reset();
+    ASSERT_EQ(counter, initial_value);
+}
+
+/**
+ * Test back and forth against an int.
+ */
+TEST(SatCounterTest, IntComparison)
+{
+    const unsigned bits = 3;
+    SatCounter counter(bits);
+    int value = 0;
+
+    ASSERT_EQ(counter++, value++);
+    ASSERT_EQ(counter++, value++);
+    ASSERT_EQ(counter--, value--);
+    ASSERT_EQ(counter++, value++);
+    ASSERT_EQ(counter++, value++);
+    ASSERT_EQ(counter--, value--);
+    ASSERT_EQ(counter++, value++);
+    ASSERT_EQ(counter--, value--);
+    ASSERT_EQ(counter--, value--);
+    ASSERT_EQ(counter++, value++);
+    ASSERT_EQ(counter--, value--);
+    ASSERT_EQ(counter--, value--);
+    ASSERT_EQ(counter, 0);
+}
+
+/**
+ * Test both pre and post operators.
+ */
+TEST(SatCounterTest, PrePostOperators)
+{
+    const unsigned bits = 3;
+    const unsigned max_value = (1 << bits) - 1;
+    SatCounter counter_pre(bits);
+    SatCounter counter_post(bits);
+
+    for (int i = 0; i < 2*max_value; i++) {
+        counter_post++;
+        SatCounter value_pre = ++counter_pre;
+        ASSERT_EQ(counter_post, value_pre);
+    }
+
+    ASSERT_EQ(counter_pre, max_value);
+    ASSERT_EQ(counter_post, max_value);
+
+    for (int i = 0; i < 2*max_value; i++) {
+        counter_post--;
+        SatCounter value_pre = --counter_pre;
+        ASSERT_EQ(counter_post, value_pre);
+    }
+
+    ASSERT_EQ(counter_pre, 0);
+    ASSERT_EQ(counter_post, 0);
+}