From: Michael Nolan <mtnolan2640@gmail.com>
Date: Mon, 4 May 2020 17:40:10 +0000 (-0400)
Subject: Have sin_cos pipeline use bigfloat calculated atan table
X-Git-Tag: ls180-24jan2020~74
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=86c586660a4e90927c16bf166e4f1829760c985e;p=ieee754fpu.git

Have sin_cos pipeline use bigfloat calculated atan table
---

diff --git a/src/ieee754/cordic/sin_cos_pipe_stage.py b/src/ieee754/cordic/sin_cos_pipe_stage.py
index 79ad6590..94916abf 100644
--- a/src/ieee754/cordic/sin_cos_pipe_stage.py
+++ b/src/ieee754/cordic/sin_cos_pipe_stage.py
@@ -2,6 +2,8 @@ from nmigen import Module, Signal
 from nmutil.pipemodbase import PipeModBase
 from ieee754.cordic.pipe_data import CordicData, CordicInitialData
 import math
+import bigfloat as bf
+from bigfloat import BigFloat
 
 
 class CordicInitialStage(PipeModBase):
@@ -47,8 +49,11 @@ class CordicStage(PipeModBase):
         dx = Signal(self.i.x.shape())
         dy = Signal(self.i.y.shape())
         dz = Signal(self.i.z.shape())
-        angle = int(round(self.pspec.M *
-                          math.atan(2**(-self.stagenum))))
+        with bf.quadruple_precision:
+            x = bf.atan(BigFloat(2) ** BigFloat(-self.stagenum))
+            x = x/(bf.const_pi()/2)
+            x = x * self.pspec.M
+            angle = int(round(x))
 
         comb += dx.eq(self.i.y >> self.stagenum)
         comb += dy.eq(self.i.x >> self.stagenum)
diff --git a/src/ieee754/cordic/test/test_pipe.py b/src/ieee754/cordic/test/test_pipe.py
deleted file mode 100644
index b7eaf8ad..00000000
--- a/src/ieee754/cordic/test/test_pipe.py
+++ /dev/null
@@ -1,89 +0,0 @@
-from nmigen import Module, Signal
-from nmigen.back.pysim import Simulator, Passive
-from nmigen.test.utils import FHDLTestCase
-from nmigen.cli import rtlil
-
-from ieee754.cordic.sin_cos_pipeline import CordicBasePipe
-from ieee754.cordic.pipe_data import CordicPipeSpec
-from python_sin_cos import run_cordic
-import unittest
-import math
-import random
-
-
-class SinCosTestCase(FHDLTestCase):
-    def run_test(self, inputs, outputs, fracbits=8):
-        m = Module()
-        pspec = CordicPipeSpec(fracbits=fracbits, rounds_per_stage=4)
-        m.submodules.dut = dut = CordicBasePipe(pspec)
-
-        for port in dut.ports():
-            print ("port", port)
-
-        vl = rtlil.convert(dut, ports=dut.ports())
-        with open("test_cordic_pipe_sin_cos.il", "w") as f:
-            f.write(vl)
-
-        z = Signal(dut.p.data_i.z0.shape())
-        z_valid = Signal()
-        ready = Signal()
-        x = Signal(dut.n.data_o.x.shape())
-        y = Signal(dut.n.data_o.y.shape())
-
-        m.d.comb += [
-            dut.p.data_i.z0.eq(z),
-            dut.p.valid_i.eq(z_valid),
-            dut.n.ready_i.eq(ready),
-            x.eq(dut.n.data_o.x),
-            y.eq(dut.n.data_o.y)]
-
-        sim = Simulator(m)
-        sim.add_clock(1e-6)
-
-        def writer_process():
-            yield Passive()
-            for val in inputs:
-                yield z.eq(val)
-                yield z_valid.eq(1)
-                yield ready.eq(1)
-                yield
-
-        def reader_process():
-            while True:
-                yield
-                vld = yield dut.n.valid_o
-                if vld:
-                    try:
-                        (sin, cos) = outputs.__next__()
-                        result = yield x
-                        msg = "cos: {}, expected {}".format(result, cos)
-                        assert result == cos, msg
-                        result = yield y
-                        msg = "sin: {}, expected {}".format(result, sin)
-                        assert result == sin, msg
-
-                    except StopIteration:
-                        break
-
-        sim.add_sync_process(writer_process)
-        sim.add_sync_process(reader_process)
-        with sim.write_vcd("pipeline.vcd", "pipeline.gtkw", traces=[
-                z, x, y]):
-            sim.run()
-
-    def test_rand(self):
-        fracbits = 16
-        M = (1 << fracbits)
-        ZMAX = int(round(M * math.pi/2))
-        inputs = []
-        outputs = []
-        for i in range(50):
-            z = random.randrange(-ZMAX, ZMAX-1)
-            (sin, cos) = run_cordic(z, fracbits=fracbits, log=False)
-            inputs.append(z)
-            outputs.append((sin, cos))
-        self.run_test(iter(inputs), iter(outputs), fracbits=fracbits)
-
-
-if __name__ == "__main__":
-    unittest.main()