Adjust 4bit test tolerance on CPU for larger blocksizes (#1749)

Author: matthewdouglas

tests/test_functional.py

@@ -1169,8 +1169,12 @@ def test_4bit_quant(self, device, dtype, quant_type, blocksize):
             4096: 0.262457,
         }
 
-        assert err < error_dict[quant_type]["err"][blocksize] + 1e-3
-        assert relerr < error_dict[quant_type]["rel_err"][blocksize] + 1e-3
+        # Allow higher tolerance for fp32 on CPU with larger block sizes
+        reltol = 2.8e-3 if dtype == torch.float32 and blocksize >= 128 and device == "cpu" else 1e-3
+        errtol = 1.2e-3 if dtype == torch.float32 and blocksize >= 1024 and device == "cpu" else 1e-3
+
+        assert err < error_dict[quant_type]["err"][blocksize] + errtol
+        assert relerr < error_dict[quant_type]["rel_err"][blocksize] + reltol
 
     @pytest.mark.parametrize("device", get_available_devices())
     @pytest.mark.parametrize("quant_type", ["fp4", "nf4"])