test symbolic view broken with jit (#14290)

test/test_jit_footguns.py

@@ -9,6 +9,7 @@ SILENT MISMATCHES (highest priority - wrong results, no error):
   class_method_shared_across_instances EASY could check if first arg is self and warn
   slice_assign_requires_realize      MED    assign graph not connected to read during JIT replay
   output_buffer_reuse                MED    performance tradeoff, could add option or better docs
+  symbolic_pad_view_frozen           MED    pad view BIND values baked in at capture time
   python_constants_frozen            HARD   inherent to tracing JITs
   conditional_branches_frozen        HARD   inherent to tracing JITs
 
@@ -134,6 +135,23 @@ class TestJitFootguns(unittest.TestCase):
       cache2.assign(Tensor.zeros(4, 4)).realize()
       self.assertEqual(f_fixed(v_pos.bind(i)).item(), 4.0)
 
+  def test_symbolic_pad_view_frozen(self):
+    """Symbolic pad view has BIND values baked in at capture time. TODO: pad should be captured in jit."""
+    from tinygrad import Variable
+    a = Tensor.rand(3, 10).realize()
+
+    # broken: pad is a view, BIND values frozen at capture (i=2)
+    @TinyJit
+    def f_broken(a): return (a+1).pad((None, (0, 10-a.shape[1]))).realize()
+    for i in range(1, 5): f_broken(a[:, :Variable("i", 1, 10).bind(i)])
+    self.assertEqual(int((f_broken(a[:, :Variable("i", 1, 10).bind(4)])[0] != 0).sum().item()), 2)  # should be 4!
+
+    # workaround: contiguous fuses pad into kernel
+    @TinyJit
+    def f_fixed(a): return (a+1).pad((None, (0, 10-a.shape[1]))).contiguous().realize()
+    for i in range(1, 5): f_fixed(a[:, :Variable("i", 1, 10).bind(i)])
+    self.assertEqual(int((f_fixed(a[:, :Variable("i", 1, 10).bind(4)])[0] != 0).sum().item()), 4)
+
   def test_non_tensor_outputs_error(self):
     @TinyJit
     def f(x, mult): return (x * 2).realize(), mult * 10