[UnitTests] Added cuDNN target to default test targets

Some unit tests explicitly test cudnn in addition to
tvm.testing.enabled_targets().  This moved the cudnn checks into the
same framework as all other targets, and adds it to the default list
of targets to be run.  Also, added `@tvm.testing.requires_cudnn` for
tests specific to cudnn.

python/tvm/testing.py

@@ -70,7 +70,8 @@ def test_something():
 import tvm.tir
 import tvm.te
 import tvm._ffi
-from tvm.contrib import nvcc
+
+from tvm.contrib import nvcc, cudnn
 from tvm.error import TVMError
 
 
@@ -375,11 +376,12 @@ def _check_forward(constraints1, constraints2, varmap, backvarmap):
 def _get_targets(target_str=None):
     if target_str is None:
         target_str = os.environ.get("TVM_TEST_TARGETS", "")
+        # Use dict instead of set for de-duplication so that the
+        # targets stay in the order specified.
+        target_names = list({t.strip(): None for t in target_str.split(";") if t.strip()})
 
-    if len(target_str) == 0:
-        target_str = DEFAULT_TEST_TARGETS
-
-    target_names = set(t.strip() for t in target_str.split(";") if t.strip())
+    if len(target_names) == 0:
+        target_names = DEFAULT_TEST_TARGETS
 
     targets = []
     for target in target_names:
@@ -413,10 +415,19 @@ def _get_targets(target_str=None):
     return targets
 
 
-DEFAULT_TEST_TARGETS = (
-    "llvm;cuda;opencl;metal;rocm;vulkan -from_device=0;nvptx;"
-    "llvm -device=arm_cpu;opencl -device=mali,aocl_sw_emu"
-)
+DEFAULT_TEST_TARGETS = [
+    "llvm",
+    "llvm -device=arm_cpu",
+    "cuda",
+    "cuda -model=unknown -libs=cudnn",
+    "nvptx",
+    "vulkan -from_device=0",
+    "opencl",
+    "opencl -device=mali,aocl_sw_emu",
+    "opencl -device=intel_graphics",
+    "metal",
+    "rocm",
+]
 
 
 def device_enabled(target):
@@ -548,6 +559,24 @@ def requires_cuda(*args):
     return _compose(args, _requires_cuda)
 
 
+def requires_cudnn(*args):
+    """Mark a test as requiring the cuDNN library.
+
+    This also marks the test as requiring a cuda gpu.
+
+    Parameters
+    ----------
+    f : function
+        Function to mark
+    """
+
+    requirements = [
+        pytest.mark.skipif(not cudnn.exists(), reason="cuDNN library not enabled, or not installed")
+        * requires_cuda(),
+    ]
+    return _compose(args, requirements)
+
+
 def requires_nvptx(*args):
     """Mark a test as requiring the NVPTX compilation on the CUDA runtime
 
@@ -730,20 +759,27 @@ def requires_rpc(*args):
 
 
 def _target_to_requirement(target):
+    if isinstance(target, str):
+        target = tvm.target.Target(target)
+
     # mapping from target to decorator
-    if target.startswith("cuda"):
-        return requires_cuda()
-    if target.startswith("rocm"):
+    if target.kind.name == "cuda":
+        if "cudnn" in target.attrs.get("libs", []):
+            return requires_cudnn()
+        else:
+            return requires_cuda()
+
+    if target.kind.name == "rocm":
         return requires_rocm()
-    if target.startswith("vulkan"):
+    if target.kind.name == "vulkan":
         return requires_vulkan()
-    if target.startswith("nvptx"):
+    if target.kind.name == "nvptx":
         return requires_nvptx()
-    if target.startswith("metal"):
+    if target.kind.name == "metal":
         return requires_metal()
-    if target.startswith("opencl"):
+    if target.kind.name == "opencl":
         return requires_opencl()
-    if target.startswith("llvm"):
+    if target.kind.name == "llvm":
         return requires_llvm()
     return []