Replace usage of fractions.gcd with a conditional that uses math.gcd if
it is available and which falls back to fractions.gcd if it is not. This
allows the code to work in Python 3.9+ where the deprecated
fractions.gcd function was removed.
If support for versions of Python older than 3.5 is dropped then this
code could be simplified to just use math.gcd.
diff --git a/compiler/front_end/expression_bounds.py b/compiler/front_end/expression_bounds.py
index 7191ada..5d37e1c 100644
--- a/compiler/front_end/expression_bounds.py
+++ b/compiler/front_end/expression_bounds.py
@@ -14,6 +14,7 @@
"""Functions for proving mathematical properties of expressions."""
+import math
import fractions
import operator
@@ -22,6 +23,14 @@
from compiler.util import traverse_ir
+# Create a local alias for math.gcd with a fallback to fractions.gcd if it is
+# not available. This can be dropped if pre-3.5 Python support is dropped.
+if hasattr(math, 'gcd'):
+ _math_gcd = math.gcd
+else:
+ _math_gcd = fractions.gcd
+
+
def compute_constraints_of_expression(expression, ir):
"""Adds appropriate bounding constraints to the given expression."""
if ir_util.is_constant_type(expression.type):
@@ -691,7 +700,7 @@
if b == 0: return a
if a == "infinity": return b
if b == "infinity": return a
- return fractions.gcd(a, b)
+ return _math_gcd(a, b)
def compute_constants(ir):
