From ce99b8848be6d4f7f86091c4dbbbcd751b527bcb Mon Sep 17 00:00:00 2001
From: Yury Popov <git@phoenix.dj>
Date: Sun, 20 Apr 2025 16:43:03 +0300
Subject: [PATCH] tests: complex logaddexp / logcumsumexp

---
 python/tests/test_ops.py | 59 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/python/tests/test_ops.py b/python/tests/test_ops.py
index 78da34f7f..13b255f8d 100644
--- a/python/tests/test_ops.py
+++ b/python/tests/test_ops.py
@@ -10,6 +10,47 @@ import mlx_tests
 import numpy as np
 
 
+def np_wrap_between(x, a):
+    """Wraps `x` between `[-a, a]`."""
+    two_a = 2 * a
+    zero = 0
+    rem = np.remainder(np.add(x, a), two_a)
+    if isinstance(rem, np.ndarray):
+        rem = np.select(rem < zero, np.add(rem, two_a), rem)
+    else:
+        rem = np.add(rem, two_a) if rem < zero else rem
+    return np.subtract(rem, a)
+
+
+def np_logaddexp(x1: np.ndarray, x2: np.ndarray):
+    amax = np.maximum(x1, x2)
+    if np.issubdtype(x1.dtype, np.floating):
+        delta = np.subtract(x1, x2)
+        if isinstance(delta, np.ndarray):
+            return np.select(
+                np.isnan(delta),
+                np.add(x1, x2),
+                np.add(amax, np.log1p(np.exp(np.negative(np.abs(delta))))),
+            )
+        else:
+            return (
+                np.add(x1, x2)
+                if np.isnan(delta)
+                else np.add(amax, np.log1p(np.exp(np.negative(np.abs(delta)))))
+            )
+    else:
+        delta = np.subtract(np.add(x1, x2), np.multiply(amax, 2))
+        out = np.add(amax, np.log1p(np.exp(delta)))
+        return np.real(out) + 1j * np_wrap_between(np.imag(out), np.pi)
+
+
+def np_cumlogaddexp(x1: np.ndarray, axis: int = -1):
+    out = x1.copy()
+    for i in range(1, out.shape[axis]):
+        out[i] = np_logaddexp(out[i], out[i - 1])
+    return out
+
+
 class TestOps(mlx_tests.MLXTestCase):
     def test_full_ones_zeros(self):
         x = mx.full(2, 3.0)
@@ -853,6 +894,16 @@ class TestOps(mlx_tests.MLXTestCase):
 
         self.assertTrue(np.allclose(result, expected))
 
+        # Complex test
+
+        a = mx.array([0, 1, 2, 9.0]) + 1j
+        b = mx.array([1, 0, 4, 2.5]) + 1j
+
+        result = mx.logaddexp(a, b)
+        expected = np_logaddexp(np.array(a), np.array(b))
+
+        self.assertTrue(np.allclose(result, expected))
+
         a = mx.array([float("nan")])
         b = mx.array([0.0])
         self.assertTrue(math.isnan(mx.logaddexp(a, b).item()))
@@ -1888,6 +1939,14 @@ class TestOps(mlx_tests.MLXTestCase):
             c_mlx = mxop(a_mlx, axis=0)
             self.assertTrue(np.allclose(c_npy, c_mlx, rtol=1e-3, atol=1e-3))
 
+        # Complex tests
+
+        a_npy = np.array([1, 2, 3]).astype(np.float32) + 1j
+        a_mlx = mx.array(a_npy)
+        c_npy = np_cumlogaddexp(a_npy, axis=-1)
+        c_mlx = mxop(a_mlx, axis=-1)
+        self.assertTrue(np.allclose(c_npy, c_mlx, rtol=1e-3, atol=1e-3))
+
     def test_scans(self):
         a_npy = np.random.randn(32, 32, 32).astype(np.float32)
         a_mlx = mx.array(a_npy)