fix and test (tinygrad#8814)

Co-authored-by: chenyu <chenyu@fastmail.com>

Author: ignaciosica

test/test_renderer_failures.py

@@ -8,6 +8,7 @@
 from tinygrad.engine.realize import CompiledRunner
 from tinygrad.helpers import dedup, flatten, prod
 from tinygrad.renderer.cstyle import CStyleLanguage
+from tinygrad.renderer.ptx import PTXRenderer
 from tinygrad.ops import UOp, Ops
 from tinygrad.renderer import ProgramSpec
 from tinygrad.tensor import Tensor, _to_np_dtype
@@ -41,7 +42,7 @@ def test_inline_const_alu(self):
     ret = _test_uop_result([Tensor([1])], uops)[0]
     self.assertEqual(ret[0], 1)
 
-@unittest.skipUnless(Device[Device.DEFAULT].renderer.has_local and Device.DEFAULT == "PTX", "need local")
+@unittest.skipIf(not isinstance(Device[Device.DEFAULT].renderer, PTXRenderer), "tests for ptx renderer")
 class TestPTXFailures(unittest.TestCase):
   def test_gated_store_with_alu(self):
     a = UOp(Ops.DEFINE_GLOBAL, dtypes.int.ptr(), (), 0)
@@ -63,5 +64,12 @@ def test_gated_store_with_if(self):
     ret = _test_uop_result([], uops, local_size=[4, 1, 1])[0]
     np.testing.assert_equal(ret, [0, 1, 1, 1])
 
+  def test_gated_define_acc_with_half_dtype(self):
+    a = Tensor.randn(32, 32, dtype=dtypes.half).realize()
+    b = Tensor.randn(34, 32, dtype=dtypes.half).realize()
+    result = a.pad((1,1)).matmul(b, acc_dtype=dtypes.half).numpy()
+    reference = a.pad((1,1)).matmul(b, acc_dtype=dtypes.float).numpy()
+    np.testing.assert_allclose(result, reference)
+
 if __name__ == '__main__':
   unittest.main()

tinygrad/renderer/ptx.py

@@ -176,8 +176,7 @@ def ssa(prefix:str, u:UOp|None=None, dtype:str|None=None) -> str:
       if u.op in {Ops.CAST, Ops.BITCAST} and (u.src[0].dtype == u.dtype or isinstance(u.src[0].dtype, PtrDType)):
         r[u] = r[u.src[0]]
         continue
-      if u.op is Ops.DEFINE_ACC and u.dtype in [dtypes.half, dtypes.bool]: r[u.src[0]] = ssa("const", u.src[0])
-      elif u.op is Ops.SPECIAL: r[u] = "%" + u.arg[0]
+      if u.op is Ops.SPECIAL: r[u] = "%" + u.arg[0]
       elif u.op is Ops.DEFINE_VAR: bufs.append((u.arg[0], u.dtype))
       elif u.op is Ops.LOAD:
         assert u.src[0].dtype == dtypes.int64, "load isn't int64"