Fix flaky ReplaceTrivialConvWithLinear pass validation tolerance (#18482)

Differential Revision: D98001101

Pull Request resolved: #18482

Author: hsharma35

backends/cadence/aot/tests/test_replace_ops_passes.py

@@ -1242,9 +1242,17 @@ def test_replace_conv1d_with_linear(self) -> None:
         self.assertTrue(result.modified)
         graph_after_passes = result.graph_module
 
-        # Validate numerical accuracy
+        # Conv and linear compute the same dot product but accumulate fp32
+        # terms in different order, so non-associativity of floating-point
+        # addition produces diffs up to ~1.2e-05. Use rtol=2e-05.
         inputs = [x, weights, bias]
-        validate(gm_before, graph_after_passes, inputs, "ReplaceTrivialConvWithLinear")
+        validate(
+            gm_before,
+            graph_after_passes,
+            inputs,
+            "ReplaceTrivialConvWithLinear",
+            rtol=2e-5,
+        )
 
         # Assert that conv1d is trivially converted to linear
         self.assertEqual(
@@ -1278,9 +1286,17 @@ def test_replace_conv2d_with_linear(self) -> None:
         self.assertTrue(result.modified)
         graph_after_passes = result.graph_module
 
-        # Validate numerical accuracy
+        # Conv and linear compute the same dot product but accumulate fp32
+        # terms in different order, so non-associativity of floating-point
+        # addition produces diffs up to ~1.2e-05. Use rtol=2e-05.
         inputs = [x, weights, bias]
-        validate(gm_before, graph_after_passes, inputs, "ReplaceTrivialConvWithLinear")
+        validate(
+            gm_before,
+            graph_after_passes,
+            inputs,
+            "ReplaceTrivialConvWithLinear",
+            rtol=2e-5,
+        )
 
         # Assert that conv2d is trivially converted to linear
         self.assertEqual(