Merge pull request #5 from litghost/add_bits_test

Add tests for new Bits library.

1 files changed, 57 insertions, 0 deletions

diff --git a/fpga_interchange/bits.cc b/fpga_interchange/bits.cc
new file mode 100644
index 0000000..49a4c28
--- /dev/null
+++ b/fpga_interchange/bits.cc
@@ -0,0 +1,57 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2021  Symbiflow Authors
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "gtest/gtest.h"
+
+#include "nextpnr.h"
+#include "bits.h"
+
+namespace nextpnr {
+
+class BitsTest : public ::testing::Test
+{
+};
+
+TEST_F(BitsTest, popcount)
+{
+    ASSERT_EQ(Bits::popcount(0), 0);
+    ASSERT_EQ(Bits::generic_popcount(0), 0);
+    for(size_t i = 0; i < std::numeric_limits<unsigned int>::digits; ++i) {
+        ASSERT_EQ(Bits::popcount(1 << i), 1);
+        ASSERT_EQ(Bits::generic_popcount(1 << i), 1);
+    }
+
+    ASSERT_EQ(Bits::popcount(std::numeric_limits<unsigned int>::max()), std::numeric_limits<unsigned int>::digits);
+    ASSERT_EQ(Bits::generic_popcount(std::numeric_limits<unsigned int>::max()), std::numeric_limits<unsigned int>::digits);
+}
+
+TEST_F(BitsTest, ctz)
+{
+    for(size_t i = 0; i < std::numeric_limits<unsigned int>::digits; ++i) {
+        ASSERT_EQ(Bits::ctz(1 << i), i);
+        ASSERT_EQ(Bits::generic_ctz(1 << i), i);
+    }
+
+    for(size_t i = 0; i < std::numeric_limits<unsigned int>::digits-1; ++i) {
+        ASSERT_EQ(Bits::ctz((1 << i) | (1 << (i+1))), i);
+        ASSERT_EQ(Bits::generic_ctz((1 << i) | (1 << (i+1))), i);
+    }
+}
+
+};