fix build on windows

Author: kumaraditya303

Include/internal/pycore_dict.h

@@ -145,7 +145,7 @@ PyAPI_FUNC(int) _PyDict_SetItem_KnownHash_LockHeld(PyDictObject *mp, PyObject *k
                                                    PyObject *value, Py_hash_t hash);
 // Export for '_asyncio' shared extension
 PyAPI_FUNC(int) _PyDict_GetItemRef_KnownHash_LockHeld(PyDictObject *op, PyObject *key, Py_hash_t hash, PyObject **result);
-extern int _PyDict_GetItemRef_KnownHash(PyDictObject *op, PyObject *key, Py_hash_t hash, PyObject **result);
+PyAPI_FUNC(int) _PyDict_GetItemRef_KnownHash(PyDictObject *op, PyObject *key, Py_hash_t hash, PyObject **result);
 extern int _PyDict_GetItemRef_Unicode_LockHeld(PyDictObject *op, PyObject *key, PyObject **result);
 PyAPI_FUNC(int) _PyObjectDict_SetItem(PyTypeObject *tp, PyObject *obj, PyObject **dictptr, PyObject *name, PyObject *value);
 

bench_dict_known_hash.py

@@ -0,0 +1,63 @@
+import time
+
+N = 50_000_000
+
+
+def bench_get_str(n):
+    d = {'a': 1, 'b': 2, 'c': 3}
+    x = 0
+    for _ in range(n):
+        x += d['a']
+    return x
+
+
+def bench_get_int(n):
+    d = {1: 10, 2: 20, 3: 30}
+    x = 0
+    for _ in range(n):
+        x += d[1]
+    return x
+
+
+def bench_store_str(n):
+    d = {}
+    for _ in range(n):
+        d['a'] = 1
+    return d
+
+
+def bench_store_int(n):
+    d = {}
+    for _ in range(n):
+        d[1] = 1
+    return d
+
+
+def bench_get_multi(n):
+    d = {'a': 1, 1: 2, b'x': 3, (1, 2): 4}
+    x = 0
+    for _ in range(n):
+        x += d['a'] + d[1] + d[b'x'] + d[(1, 2)]
+    return x
+
+
+def run(name, func, n):
+    # warmup
+    func(1000)
+    t0 = time.perf_counter()
+    func(n)
+    dt = time.perf_counter() - t0
+    print(f"{name:25s}  {dt:.3f}s  ({n/dt/1e6:.1f}M iter/s)")
+
+
+if __name__ == "__main__":
+    import sys
+    import os
+    jit = "JIT" if os.environ.get("PYTHON_JIT", "1") == "1" else "no JIT"
+    print(f"Python {sys.version.split()[0]} ({jit})\n")
+
+    run("dict_get[str]",    bench_get_str,   N)
+    run("dict_get[int]",    bench_get_int,   N)
+    run("dict_store[str]",  bench_store_str, N)
+    run("dict_store[int]",  bench_store_int, N)
+    run("dict_get[multi]",  bench_get_multi, N // 4)