Fix convit_base (#95174)

Signed-off-by: Edward Z. Yang <ezyang@meta.com>
Pull Request resolved: pytorch/pytorch#95174
Approved by: https://github.com/ngimel, https://github.com/jansel, https://github.com/atalman

test/test_sympy_utils.py

@@ -107,6 +107,9 @@ def test_unary_ref(self, fn):
                 self.assertEqual(r.lower, r.upper)
                 self.assertEqual(ref_r, r.lower)
 
+    def test_pow_half(self):
+        ValueRangeAnalysis.pow(ValueRanges.unknown(), ValueRanges.wrap(0.5))
+
     @parametrize("fn", BINARY_OPS)
     def test_binary_ref(self, fn):
         for a, b in itertools.product(CONSTANTS, repeat=2):

torch/utils/_sympy/value_ranges.py

@@ -360,14 +360,19 @@ def sqrt(x):
 
     @classmethod
     def pow(cls, a, b):
+        def is_integer(val):
+            return isinstance(val, int) or (
+                hasattr(val, "is_integer") and val.is_integer
+            )
+
         a = ValueRanges.wrap(a)
         b = ValueRanges.wrap(b)
         if a.is_singleton() and b.is_singleton():
             r = a.lower**b.lower
             if r == sympy.zoo:
                 return ValueRanges.unknown()
             return ValueRanges.wrap(r)
-        elif b.is_singleton() and b.lower >= 0 and isinstance(b.lower, int):
+        elif b.is_singleton() and is_integer(b.lower) and b.lower >= 0:
             i = ValueRanges.wrap(1)
             for _ in range(b.lower):
                 i = cls.mul(i, a)