unit test transcendental helpers (#7325)

added a test to run UOps with const inputs. seems to have issue with both payne_hanek_reduction and cody_waite_reduction

test/unit/test_transcendental_helpers.py

@@ -0,0 +1,32 @@
+import unittest, math
+import numpy as np
+from tinygrad import dtypes
+from tinygrad.ops import UOp, UOps
+from tinygrad.codegen.uopgraph import full_graph_rewrite
+from tinygrad.codegen.transcendental import payne_hanek_reduction, cody_waite_reduction
+from tinygrad.codegen.linearize import linearize_uop
+from tinygrad.runtime.ops_python import PythonProgram, PythonRenderer, PythonCompiler, PythonAllocator
+
+class TestReduction(unittest.TestCase):
+  def _run_uop(self, uop:UOp):
+    g = UOp(UOps.DEFINE_GLOBAL, uop.dtype.ptr(), arg=0, src=())
+    rw = full_graph_rewrite(UOp.store(g, UOp.const(dtypes.int, 0), uop).sink())
+    prog = PythonProgram("run", PythonCompiler().compile(PythonRenderer().render("run", linearize_uop(rw))))
+    buf = PythonAllocator().alloc(uop.dtype.itemsize)
+    prog(buf)
+    return buf.cast(uop.dtype.fmt).tolist()[0]
+
+  def test_payne_hanek_reduction(self):
+    r, q = (self._run_uop(u) for u in payne_hanek_reduction(UOp.const(dtypes.float64, 12 * math.pi + 0.1)))
+    # TODO: should r be in [0, pi/2) per doc?
+    np.testing.assert_allclose(r, 0.1 - math.pi / 2)
+    np.testing.assert_equal(q, 1)
+
+  def test_cody_waite_reduction(self):
+    r, q = (self._run_uop(u) for u in cody_waite_reduction(UOp.const(dtypes.float64, 12 * math.pi + 0.1)))
+    np.testing.assert_allclose(r, 0.1)
+    # TODO: should q be in [0, 1, 2, 3]?
+    np.testing.assert_equal(q, 12)
+
+if __name__ == '__main__':
+  unittest.main()