From: Michael Nolan <mtnolan2640@gmail.com>
Date: Tue, 14 Apr 2020 13:46:23 +0000 (-0400)
Subject: Add experiment testing the effects of adding extra bits to cordic
X-Git-Tag: ls180-24jan2020~91
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=4b349c184c640d206db6b71680b02c83993df8de;p=ieee754fpu.git

Add experiment testing the effects of adding extra bits to cordic
---

diff --git a/src/ieee754/cordic/test/test_software.py b/src/ieee754/cordic/test/test_software.py
new file mode 100644
index 00000000..d48eefb1
--- /dev/null
+++ b/src/ieee754/cordic/test/test_software.py
@@ -0,0 +1,31 @@
+import math
+import unittest
+from python_sin_cos import run_cordic
+import random
+
+class SoftwareTestCase(unittest.TestCase):
+    def test_extrabits(self):
+        fracbits = 16
+        extrabits = 18
+        M = (1 << fracbits)
+        print(M)
+        for i in range(200000):
+            f = random.uniform(-math.pi/2, math.pi/2)
+            i = int(round(f * M))
+            f = i/M
+            print(f"int: {i}, float:{f}")
+            i = i * (1<<extrabits)
+
+            expected = int(round(math.sin(f) * M))
+
+            sin, cos = run_cordic(i,
+                                  fracbits=(fracbits+extrabits),
+                                  log=False)
+            sin = int(round(sin / (1<<extrabits)))
+
+            print(f"expected: {expected}, actual: {sin}")
+            self.assertEqual(expected, sin)
+
+
+if __name__ == '__main__':
+    unittest.main()