diff --git a/tests/Android.bp b/tests/Android.bp
index 2c2c9a6..743c856 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -159,3 +159,20 @@
         "mini_cil_parser",
     ],
 }
+
+python_test_host {
+    name: "policy_test",
+    srcs: [
+        "fc_sort.py",
+        "policy.py",
+        "policy_test.py",
+    ],
+    test_options: {
+        unit_test: true,
+    },
+    version: {
+        py3: {
+            embedded_launcher: true,
+        },
+    },
+}
diff --git a/tests/policy.py b/tests/policy.py
index 805c451..9fdc43c 100644
--- a/tests/policy.py
+++ b/tests/policy.py
@@ -30,7 +30,46 @@
 # 1) there is a match - return True or 2) run out of characters - return
 #    False.
 #
+COMMON_PREFIXES = {
+    "/(vendor|system/vendor)": ["/vendor", "/system/vendor"],
+    "/(odm|vendor/odm)": ["/odm", "/vendor/odm"],
+    "/(product|system/product)": ["/product", "/system/product"],
+    "/(system_ext|system/system_ext)": ["/system_ext", "/system/system_ext"],
+}
+
 def MatchPathPrefix(pathregex, prefix):
+    # Before running regex compile loop, try two heuristics, because compiling
+    # regex is too expensive. These two can handle more than 90% out of all
+    # MatchPathPrefix calls.
+
+    # Heuristic 1: handle common prefixes for partitions
+    for c in COMMON_PREFIXES:
+        if not pathregex.startswith(c):
+            continue
+        found = False
+        for p in COMMON_PREFIXES[c]:
+            if prefix.startswith(p):
+                found = True
+                prefix = prefix[len(p):]
+                pathregex = pathregex[len(c):]
+                break
+        if not found:
+            return False
+
+    # Heuristic 2: compare normal characters as long as possible
+    idx = 0
+    while idx < len(prefix):
+        if idx == len(pathregex):
+            return False
+        if pathregex[idx] in fc_sort.META_CHARS or pathregex[idx] == '\\':
+            break
+        if pathregex[idx] != prefix[idx]:
+            return False
+        idx += 1
+    if idx == len(prefix):
+        return True
+
+    # Fall back to regex compile loop.
     for i in range(len(pathregex), 0, -1):
         try:
             pattern = re.compile('^' + pathregex[0:i] + "$")
diff --git a/tests/policy_test.py b/tests/policy_test.py
new file mode 100644
index 0000000..3cf4a1b
--- /dev/null
+++ b/tests/policy_test.py
@@ -0,0 +1,56 @@
+# Copyright 2023 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Tests for policy"""
+
+import unittest
+from policy import MatchPathPrefix
+
+# pylint: disable=missing-docstring
+class PolicyTests(unittest.TestCase):
+    def assertMatches(self, path, prefix):
+        self.assertTrue(MatchPathPrefix(path, prefix))
+
+    def assertDoesNotMatch(self, path, prefix):
+        self.assertFalse(MatchPathPrefix(path, prefix))
+
+    # tests
+
+    def test_match_path_prefix(self):
+        # check common prefix heuristics
+        self.assertMatches("/(vendor|system/vendor)/bin/sh", "/vendor/bin")
+        self.assertMatches("/(vendor|system/vendor)/bin/sh", "/system/vendor/bin"),
+        self.assertMatches("/(odm|vendor/odm)/etc/selinux", "/odm/etc"),
+        self.assertMatches("/(odm|vendor/odm)/etc/selinux", "/vendor/odm/etc"),
+        self.assertMatches("/(system_ext|system/system_ext)/bin/foo", "/system_ext/bin"),
+        self.assertMatches("/(system_ext|system/system_ext)/bin/foo", "/system/system_ext/bin"),
+        self.assertMatches("/(product|system/product)/lib/libc.so", "/product/lib"),
+        self.assertMatches("/(product|system/product)/lib/libc.so", "/system/product/lib"),
+        self.assertDoesNotMatch("/(vendor|system/vendor)/bin/sh", "/system/bin"),
+        self.assertDoesNotMatch("/(odm|vendor/odm)/etc/selinux", "/vendor/etc"),
+        self.assertDoesNotMatch("/(system_ext|system/system_ext)/bin/foo", "/system/bin"),
+        self.assertDoesNotMatch("/(product|system/product)/lib/libc.so", "/system/lib"),
+
+        # check generic regex
+        self.assertMatches("(/.*)+", "/system/etc/vintf")
+        self.assertDoesNotMatch("(/.*)+", "foo/bar/baz")
+
+        self.assertMatches("/(system|product)/lib(64)?(/.*)+.*\.so", "/system/lib/hw/libbaz.so")
+        self.assertMatches("/(system|product)/lib(64)?(/.*)+.*\.so", "/system/lib64/")
+        self.assertMatches("/(system|product)/lib(64)?(/.*)+.*\.so", "/product/lib/hw/libbaz.so")
+        self.assertMatches("/(system|product)/lib(64)?(/.*)+.*\.so", "/product/lib64/")
+        self.assertDoesNotMatch("/(system|product)/lib(64)?(/.*)+.*\.so", "/vendor/lib/hw/libbaz.so")
+        self.assertDoesNotMatch("/(system|product)/lib(64)?(/.*)+.*\.so", "/odm/lib64/")
+
+if __name__ == '__main__':
+    unittest.main(verbosity=2)