base: Add function to saturate SatCounter
Create a saturation function for the SatCounter that makes its
internal counter reach its maximum value.
Change-Id: Ibd30fa27c4ae2714dd48e3eba85addd035fb737c
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20451
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
diff --git a/src/base/sat_counter.hh b/src/base/sat_counter.hh
index 3de9486..6aeca68 100644
--- a/src/base/sat_counter.hh
+++ b/src/base/sat_counter.hh
@@ -235,6 +235,18 @@
*/
bool isSaturated() const { return counter == maxVal; }
+ /**
+ * Saturate the counter.
+ *
+ * @return The value added to the counter to reach saturation.
+ */
+ uint8_t saturate()
+ {
+ const uint8_t diff = maxVal - counter;
+ counter = maxVal;
+ return diff;
+ }
+
private:
uint8_t initialVal;
uint8_t maxVal;
diff --git a/src/base/sat_counter.test.cc b/src/base/sat_counter.test.cc
index dbdaf0a..817f2c7 100644
--- a/src/base/sat_counter.test.cc
+++ b/src/base/sat_counter.test.cc
@@ -97,6 +97,23 @@
}
/**
+ * Test abrupt saturation.
+ */
+TEST(SatCounterTest, Saturate)
+{
+ const unsigned bits = 3;
+ const unsigned max_value = (1 << bits) - 1;
+ SatCounter counter(bits);
+ counter++;
+ ASSERT_FALSE(counter.isSaturated());
+
+ // Make sure the value added is what was missing to saturate
+ const unsigned diff = counter.saturate();
+ ASSERT_EQ(diff, max_value - 1);
+ ASSERT_TRUE(counter.isSaturated());
+}
+
+/**
* Test back and forth against an int.
*/
TEST(SatCounterTest, IntComparison)
