Quick test to see if removing the tier2 interpreter speeds up tier1

Include/internal/pycore_code.h

@@ -300,7 +300,7 @@ extern int _PyStaticCode_Init(PyCodeObject *co);
 #define STAT_INC(opname, name) do { if (_Py_stats) _Py_stats->opcode_stats[opname].specialization.name++; } while (0)
 #define STAT_DEC(opname, name) do { if (_Py_stats) _Py_stats->opcode_stats[opname].specialization.name--; } while (0)
 #define OPCODE_EXE_INC(opname) do { if (_Py_stats) _Py_stats->opcode_stats[opname].execution_count++; } while (0)
-#define CALL_STAT_INC(name) do { if (_Py_stats) _Py_stats->call_stats.name++; } while (0)
+#define REAL_CALL_STAT_INC(name) do { if (_Py_stats) _Py_stats->call_stats.name++; } while (0)
 #define OBJECT_STAT_INC(name) do { if (_Py_stats) _Py_stats->object_stats.name++; } while (0)
 #define OBJECT_STAT_INC_COND(name, cond) \
     do { if (_Py_stats && cond) _Py_stats->object_stats.name++; } while (0)
@@ -329,7 +329,7 @@ PyAPI_FUNC(PyObject*) _Py_GetSpecializationStats(void);
 #define STAT_INC(opname, name) ((void)0)
 #define STAT_DEC(opname, name) ((void)0)
 #define OPCODE_EXE_INC(opname) ((void)0)
-#define CALL_STAT_INC(name) ((void)0)
+#define REAL_CALL_STAT_INC(name) ((void)0)
 #define OBJECT_STAT_INC(name) ((void)0)
 #define OBJECT_STAT_INC_COND(name, cond) ((void)0)
 #define EVAL_CALL_STAT_INC(name) ((void)0)
@@ -343,6 +343,9 @@ PyAPI_FUNC(PyObject*) _Py_GetSpecializationStats(void);
 #define RARE_EVENT_STAT_INC(name) ((void)0)
 #endif  // !Py_STATS
 
+// We do a little dance here so we can redefine and restore CALL_STAT_INC
+#define CALL_STAT_INC(name) REAL_CALL_STAT_INC(name)
+
 // Utility functions for reading/writing 32/64-bit values in the inline caches.
 // Great care should be taken to ensure that these functions remain correct and
 // performant! They should compile to just "move" instructions on all supported

Include/internal/pycore_jit.h

@@ -11,6 +11,10 @@ extern "C" {
 
 #ifdef _Py_JIT
 
+#ifdef _Py_NOTIER2
+#  error "can't define _Py_JIT and _Py_NOTIER2 at the same time"
+#endif
+
 typedef _Py_CODEUNIT *(*jit_func)(_PyInterpreterFrame *frame, PyObject **stack_pointer, PyThreadState *tstate);
 
 int _PyJIT_Compile(_PyExecutorObject *executor, const _PyUOpInstruction *trace, size_t length);

Lib/test/support/__init__.py

@@ -1188,6 +1188,10 @@ def requires_specialization(test):
         _opcode.ENABLE_SPECIALIZATION, "requires specialization")(test)
 
 
+def requires_tier2(test):
+    return unittest.skipIf(_opcode.NOTIER2, "requires tier2")(test)
+
+
 #=======================================================================
 # Check for the presence of docstrings.
 

Lib/test/test_capi/test_opt.py

@@ -7,7 +7,7 @@
 
 import _opcode
 
-from test.support import script_helper, requires_specialization, import_helper
+from test.support import script_helper, requires_specialization, requires_tier2, import_helper
 
 _testinternalcapi = import_helper.import_module("_testinternalcapi")
 
@@ -33,6 +33,7 @@ def clear_executors(func):
         func.__code__ = func.__code__.replace()
 
 
+@requires_tier2
 @requires_specialization
 class TestOptimizerAPI(unittest.TestCase):
 
@@ -136,6 +137,7 @@ def get_opnames(ex):
 
 
 @requires_specialization
+@requires_tier2
 class TestExecutorInvalidation(unittest.TestCase):
 
     def setUp(self):
@@ -215,6 +217,7 @@ def f():
 
 
 @requires_specialization
+@requires_tier2
 @unittest.skipIf(os.getenv("PYTHON_UOPS_OPTIMIZE") == "0", "Needs uop optimizer to run.")
 class TestUops(unittest.TestCase):
 
@@ -579,6 +582,7 @@ def testfunc(n):
 
 
 @requires_specialization
+@requires_tier2
 @unittest.skipIf(os.getenv("PYTHON_UOPS_OPTIMIZE") == "0", "Needs uop optimizer to run.")
 class TestUopsOptimization(unittest.TestCase):
 

Makefile.pre.in

@@ -100,7 +100,7 @@ CONFIGURE_LDFLAGS=	@LDFLAGS@
 # command line to append to these values without stomping the pre-set
 # values.
 PY_CFLAGS=	$(BASECFLAGS) $(OPT) $(CONFIGURE_CFLAGS) $(CFLAGS) $(EXTRA_CFLAGS)
-PY_CFLAGS_NODIST=$(CONFIGURE_CFLAGS_NODIST) $(CFLAGS_NODIST) -I$(srcdir)/Include/internal -I$(srcdir)/Include/internal/mimalloc
+PY_CFLAGS_NODIST=$(CONFIGURE_CFLAGS_NODIST) $(CFLAGS_NODIST) -I$(srcdir)/Include/internal -I$(srcdir)/Include/internal/mimalloc -D_Py_NOTIER2
 # Both CPPFLAGS and LDFLAGS need to contain the shell's value for setup.py to
 # be able to build extension modules using the directories specified in the
 # environment variables

Modules/_opcode.c

@@ -394,6 +394,14 @@ _opcode_exec(PyObject *m) {
     if (PyModule_AddIntMacro(m, ENABLE_SPECIALIZATION) < 0) {
         return -1;
     }
+#ifdef _Py_NOTIER2
+    int notier2 = 1;
+#else
+    int notier2 = 0;
+#endif
+    if (PyModule_AddIntConstant(m, "NOTIER2", notier2) < 0) {
+        return -1;
+    }
     return 0;
 }
 

Python/bytecodes.c

@@ -2339,6 +2339,7 @@ dummy_func(
             CHECK_EVAL_BREAKER();
             assert(oparg <= INSTR_OFFSET());
             JUMPBY(-oparg);
+            #ifndef _Py_NOTIER2
             #if ENABLE_SPECIALIZATION
             _Py_BackoffCounter counter = this_instr[1].counter;
             if (backoff_counter_triggers(counter) && this_instr->op.code == JUMP_BACKWARD) {
@@ -2364,6 +2365,7 @@ dummy_func(
                 ADVANCE_ADAPTIVE_COUNTER(this_instr[1].counter);
             }
             #endif  /* ENABLE_SPECIALIZATION */
+            #endif  /* _Py_NOTIER2 */
         }
 
         pseudo(JUMP) = {
@@ -2377,6 +2379,9 @@ dummy_func(
         };
 
         tier1 inst(ENTER_EXECUTOR, (--)) {
+            #ifdef _Py_NOTIER2
+            assert(0);
+            #else
             CHECK_EVAL_BREAKER();
             PyCodeObject *code = _PyFrame_GetCode(frame);
             _PyExecutorObject *executor = code->co_executors->executors[oparg & 255];
@@ -2387,23 +2392,28 @@ dummy_func(
             tstate->previous_executor = Py_None;
             Py_INCREF(executor);
             GOTO_TIER_TWO(executor);
+            #endif  // _Py_NOTIER2
         }
 
         replaced op(_POP_JUMP_IF_FALSE, (cond -- )) {
             assert(PyBool_Check(cond));
             int flag = Py_IsFalse(cond);
+            #ifndef _Py_NOTIER2
             #if ENABLE_SPECIALIZATION
             this_instr[1].cache = (this_instr[1].cache << 1) | flag;
             #endif
+            #endif
             JUMPBY(oparg * flag);
         }
 
         replaced op(_POP_JUMP_IF_TRUE, (cond -- )) {
             assert(PyBool_Check(cond));
             int flag = Py_IsTrue(cond);
+            #ifndef _Py_NOTIER2
             #if ENABLE_SPECIALIZATION
             this_instr[1].cache = (this_instr[1].cache << 1) | flag;
             #endif
+            #endif
             JUMPBY(oparg * flag);
         }
 
@@ -3973,9 +3983,11 @@ dummy_func(
             assert(PyBool_Check(cond));
             int flag = Py_IsTrue(cond);
             int offset = flag * oparg;
+            #ifndef _Py_NOTIER2
             #if ENABLE_SPECIALIZATION
             this_instr[1].cache = (this_instr[1].cache << 1) | flag;
             #endif
+            #endif
             INSTRUMENTED_JUMP(this_instr, next_instr + offset, PY_MONITORING_EVENT_BRANCH);
         }
 
@@ -3984,9 +3996,11 @@ dummy_func(
             assert(PyBool_Check(cond));
             int flag = Py_IsFalse(cond);
             int offset = flag * oparg;
+            #ifndef _Py_NOTIER2
             #if ENABLE_SPECIALIZATION
             this_instr[1].cache = (this_instr[1].cache << 1) | flag;
             #endif
+            #endif
             INSTRUMENTED_JUMP(this_instr, next_instr + offset, PY_MONITORING_EVENT_BRANCH);
         }
 
@@ -4001,9 +4015,11 @@ dummy_func(
                 Py_DECREF(value);
                 offset = 0;
             }
+            #ifndef _Py_NOTIER2
             #if ENABLE_SPECIALIZATION
             this_instr[1].cache = (this_instr[1].cache << 1) | flag;
             #endif
+            #endif
             INSTRUMENTED_JUMP(this_instr, next_instr + offset, PY_MONITORING_EVENT_BRANCH);
         }
 
@@ -4018,9 +4034,11 @@ dummy_func(
                 Py_DECREF(value);
                 offset = oparg;
             }
+            #ifndef _Py_NOTIER2
             #if ENABLE_SPECIALIZATION
             this_instr[1].cache = (this_instr[1].cache << 1) | !nflag;
             #endif
+            #endif
             INSTRUMENTED_JUMP(this_instr, next_instr + offset, PY_MONITORING_EVENT_BRANCH);
         }
 

Python/ceval.c

@@ -678,6 +678,7 @@ extern void _PyUOpPrint(const _PyUOpInstruction *uop);
  * so consume 3 units of C stack */
 #define PY_EVAL_C_STACK_UNITS 2
 
+#ifndef _Py_NOTIER2
 #if defined(_MSC_VER) && defined(_Py_USING_PGO)
 /* gh-111786: _PyEval_EvalFrameDefault is too large to optimize for speed with
    PGO on MSVC. Disable that optimization temporarily. If this is fixed
@@ -686,6 +687,7 @@ extern void _PyUOpPrint(const _PyUOpInstruction *uop);
 #  pragma optimize("t", off)
 /* This setting is reversed below following _PyEval_EvalFrameDefault */
 #endif
+#endif
 
 PyObject* _Py_HOT_FUNCTION
 _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int throwflag)
@@ -754,11 +756,13 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
     _Py_CODEUNIT *next_instr;
     PyObject **stack_pointer;
 
+#ifndef _Py_NOTIER2
 #ifndef _Py_JIT
     /* Tier 2 interpreter state */
     _PyExecutorObject *current_executor = NULL;
     const _PyUOpInstruction *next_uop = NULL;
 #endif
+#endif
 
 start_frame:
     if (_Py_EnterRecursivePy(tstate)) {
@@ -958,6 +962,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
     goto error;
 
 
+#ifndef _Py_NOTIER2
 
 // Tier 2 is also here!
 enter_tier_two:
@@ -1108,14 +1113,29 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
 
 #endif  // _Py_JIT
 
+#endif  // _Py_NOTIER2
+
+// Undefine the macros we redefined, to avoid using the wrong ones below
+#undef LOAD_IP
+#undef GOTO_ERROR
+#undef ENABLE_SPECIALIZATION
+#undef STAT_INC
+#undef STAT_DEC
+#undef CALL_STAT_INC
+
+// Restore this one
+#define CALL_STAT_INC(name) REAL_CALL_STAT_INC(name)
+
 }
 
 #if defined(__GNUC__)
 #  pragma GCC diagnostic pop
 #elif defined(_MSC_VER) /* MS_WINDOWS */
 #  pragma warning(pop)
+#ifdef _Py_NOTIER2
 #  pragma optimize("", on)
 #endif
+#endif
 
 static void
 format_missing(PyThreadState *tstate, const char *kind,