[TOPHUB] use keys as a keyword for searching of existing statistics (#13874)

* [TOPHUB] use keys as a keyword for searching of existing statistics

In case of ARM we might not specify -device and in this case llvm will
be used while even in this case we can determin proper filename with
stat since keys have architecture defined. The same situatin must with
with x86

* Add test on target not having arm_cpu device

* minor fix, add comment

* Fix pylint

* Fix comment

Author: elvin-n

python/tvm/autotvm/tophub.py

@@ -106,10 +106,20 @@ def context(target, extra_files=None):
         if isinstance(tgt, str):
             tgt = Target(tgt)
 
+        # The TOPHUB file names rely on Target's device or kind. Both these types of
+        # information exist in Target.keys, but rules of filling this filed is not explicitly
+        # defined, we are afraid to rely only on Target.keys. At the same time Target.device
+        # is filled only if device was pointed explicitly in target string, that is not mandatory
+        # and in some cases we need to get information about device from Target.keys
+        # In priority order we verify:
+        # 1) Target.device
+        # 2) Target.keys
+        # 3) Target.kind
         possible_names = []
         device = tgt.attrs.get("device", "")
         if device != "":
             possible_names.append(_alias(device))
+        possible_names.extend(tgt.keys)
         possible_names.append(tgt.kind.name)
 
         all_packages = list(PACKAGE_VERSION.keys())

tests/python/unittest/test_autotvm_dispatch_context.py

@@ -19,6 +19,7 @@
 to the parameters of workload"""
 
 from tvm import autotvm
+import tvm
 
 
 @autotvm.template("testing/dispatch_fallback")
@@ -31,5 +32,20 @@ def test_fallback():
     simple_template(2, 3)
 
 
+def test_tophub_kinds_match():
+    def verify_arm_cpu(target):
+        best_by_targetkey = autotvm.tophub.context(target).best_by_targetkey
+        assert len(best_by_targetkey)
+        found_arm_cpu = False
+        for a, _ in best_by_targetkey:
+            if "arm_cpu" in a:
+                found_arm_cpu = True
+                break
+        assert found_arm_cpu
+
+    verify_arm_cpu("llvm -device=arm_cpu -mtriple=aarch64-linux-gnu -mattr=+neon,+v8.2a,+dotprod")
+    verify_arm_cpu("llvm -model=snapdragon835 -mtriple=arm64-linux-android -mattr=+neon")
+
+
 if __name__ == "__main__":
     test_fallback()