diff --git a/benchmarks/dynamo/pr_time_benchmarks/benchmarks/sum_floordiv_benchmark.py b/benchmarks/dynamo/pr_time_benchmarks/benchmarks/sum_floordiv_benchmark.py
new file mode 100644
index 00000000000000..227c0bd911ada3
--- /dev/null
+++ b/benchmarks/dynamo/pr_time_benchmarks/benchmarks/sum_floordiv_benchmark.py
@@ -0,0 +1,39 @@
+import sys
+
+from benchmark_base import BenchmarkBase
+
+import torch
+
+
+class Benchmark(BenchmarkBase):
+    N = 100
+
+    def name(self):
+        return "sum_floordiv_regression"
+
+    def description(self):
+        return "information at https://github.com/pytorch/pytorch/issues/134133"
+
+    def prepare_once(self):
+        class M(torch.nn.Module):
+            def forward(self, x):
+                total = sum(t.item() for t in x)
+                return total // 2
+
+        self.m = M()
+        self.input = [torch.tensor(i + 2) for i in range(self.N)]
+
+    def prepare(self):
+        torch._dynamo.reset()
+
+    def work(self):
+        torch.export.export(self.m, (self.input,))
+
+
+def main():
+    result_path = sys.argv[1]
+    Benchmark().enable_instruction_count().collect_all().append_results(result_path)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/torch/utils/_sympy/functions.py b/torch/utils/_sympy/functions.py
index 0998b57678610a..d54495047e2713 100644
--- a/torch/utils/_sympy/functions.py
+++ b/torch/utils/_sympy/functions.py
@@ -186,7 +186,8 @@ def eval(cls, base, divisor):
 
         # Expands (x + y) // b into x // b + y // b.
         # This only works if floor is an identity, i.e. x / b is an integer.
-        for term in sympy.Add.make_args(base):
+        base_args = sympy.Add.make_args(base)
+        for term in base_args:
             quotient = term / divisor
             if quotient.is_integer and isinstance(divisor, sympy.Integer):
                 # NB: this is correct even if the divisor is not an integer, but it
@@ -195,8 +196,11 @@ def eval(cls, base, divisor):
                 return FloorDiv(base - term, divisor) + quotient
 
         try:
-            gcd = sympy.gcd(base, divisor)
-            if not equal_valued(gcd, 1):
+            # sympy.gcd tends to blow up on large sums, so use it on each summand instead
+            gcd, *gcds_ = (sympy.gcd(term, divisor) for term in base_args)
+            if not equal_valued(gcd, 1) and all(
+                equal_valued(gcd, gcd_) for gcd_ in gcds_
+            ):
                 return FloorDiv(
                     sympy.simplify(base / gcd), sympy.simplify(divisor / gcd)
                 )