| // Macros and other things needed by ceval.c, and bytecodes.c |
| |
| /* Computed GOTOs, or |
| the-optimization-commonly-but-improperly-known-as-"threaded code" |
| using gcc's labels-as-values extension |
| (http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html). |
| |
| The traditional bytecode evaluation loop uses a "switch" statement, which |
| decent compilers will optimize as a single indirect branch instruction |
| combined with a lookup table of jump addresses. However, since the |
| indirect jump instruction is shared by all opcodes, the CPU will have a |
| hard time making the right prediction for where to jump next (actually, |
| it will be always wrong except in the uncommon case of a sequence of |
| several identical opcodes). |
| |
| "Threaded code" in contrast, uses an explicit jump table and an explicit |
| indirect jump instruction at the end of each opcode. Since the jump |
| instruction is at a different address for each opcode, the CPU will make a |
| separate prediction for each of these instructions, which is equivalent to |
| predicting the second opcode of each opcode pair. These predictions have |
| a much better chance to turn out valid, especially in small bytecode loops. |
| |
| A mispredicted branch on a modern CPU flushes the whole pipeline and |
| can cost several CPU cycles (depending on the pipeline depth), |
| and potentially many more instructions (depending on the pipeline width). |
| A correctly predicted branch, however, is nearly free. |
| |
| At the time of this writing, the "threaded code" version is up to 15-20% |
| faster than the normal "switch" version, depending on the compiler and the |
| CPU architecture. |
| |
| NOTE: care must be taken that the compiler doesn't try to "optimize" the |
| indirect jumps by sharing them between all opcodes. Such optimizations |
| can be disabled on gcc by using the -fno-gcse flag (or possibly |
| -fno-crossjumping). |
| */ |
| |
| /* Use macros rather than inline functions, to make it as clear as possible |
| * to the C compiler that the tracing check is a simple test then branch. |
| * We want to be sure that the compiler knows this before it generates |
| * the CFG. |
| */ |
| |
| #ifdef WITH_DTRACE |
| #define OR_DTRACE_LINE | (PyDTrace_LINE_ENABLED() ? 255 : 0) |
| #else |
| #define OR_DTRACE_LINE |
| #endif |
| |
| #ifdef HAVE_COMPUTED_GOTOS |
| #ifndef USE_COMPUTED_GOTOS |
| #define USE_COMPUTED_GOTOS 1 |
| #endif |
| #else |
| #if defined(USE_COMPUTED_GOTOS) && USE_COMPUTED_GOTOS |
| #error "Computed gotos are not supported on this compiler." |
| #endif |
| #undef USE_COMPUTED_GOTOS |
| #define USE_COMPUTED_GOTOS 0 |
| #endif |
| |
| #ifdef Py_STATS |
| #define INSTRUCTION_STATS(op) \ |
| do { \ |
| OPCODE_EXE_INC(op); \ |
| if (_Py_stats) _Py_stats->opcode_stats[lastopcode].pair_count[op]++; \ |
| lastopcode = op; \ |
| } while (0) |
| #else |
| #define INSTRUCTION_STATS(op) ((void)0) |
| #endif |
| |
| #if USE_COMPUTED_GOTOS |
| # define TARGET(op) TARGET_##op: |
| # define DISPATCH_GOTO() goto *opcode_targets[opcode] |
| #else |
| # define TARGET(op) case op: TARGET_##op: |
| # define DISPATCH_GOTO() goto dispatch_opcode |
| #endif |
| |
| /* PRE_DISPATCH_GOTO() does lltrace if enabled. Normally a no-op */ |
| #ifdef LLTRACE |
| #define PRE_DISPATCH_GOTO() if (lltrace >= 5) { \ |
| lltrace_instruction(frame, stack_pointer, next_instr, opcode, oparg); } |
| #else |
| #define PRE_DISPATCH_GOTO() ((void)0) |
| #endif |
| |
| #if LLTRACE |
| #define LLTRACE_RESUME_FRAME() \ |
| do { \ |
| lltrace = maybe_lltrace_resume_frame(frame, &entry_frame, GLOBALS()); \ |
| if (lltrace < 0) { \ |
| goto exit_unwind; \ |
| } \ |
| } while (0) |
| #else |
| #define LLTRACE_RESUME_FRAME() ((void)0) |
| #endif |
| |
| #ifdef Py_GIL_DISABLED |
| #define QSBR_QUIESCENT_STATE(tstate) _Py_qsbr_quiescent_state(((_PyThreadStateImpl *)tstate)->qsbr) |
| #else |
| #define QSBR_QUIESCENT_STATE(tstate) |
| #endif |
| |
| |
| /* Do interpreter dispatch accounting for tracing and instrumentation */ |
| #define DISPATCH() \ |
| { \ |
| NEXTOPARG(); \ |
| PRE_DISPATCH_GOTO(); \ |
| DISPATCH_GOTO(); \ |
| } |
| |
| #define DISPATCH_SAME_OPARG() \ |
| { \ |
| opcode = next_instr->op.code; \ |
| PRE_DISPATCH_GOTO(); \ |
| DISPATCH_GOTO(); \ |
| } |
| |
| #define DISPATCH_INLINED(NEW_FRAME) \ |
| do { \ |
| assert(tstate->interp->eval_frame == NULL); \ |
| _PyFrame_SetStackPointer(frame, stack_pointer); \ |
| (NEW_FRAME)->previous = frame; \ |
| frame = tstate->current_frame = (NEW_FRAME); \ |
| CALL_STAT_INC(inlined_py_calls); \ |
| goto start_frame; \ |
| } while (0) |
| |
| // Use this instead of 'goto error' so Tier 2 can go to a different label |
| #define GOTO_ERROR(LABEL) goto LABEL |
| |
| #define CHECK_EVAL_BREAKER() \ |
| _Py_CHECK_EMSCRIPTEN_SIGNALS_PERIODICALLY(); \ |
| QSBR_QUIESCENT_STATE(tstate); \ |
| if (_Py_atomic_load_uintptr_relaxed(&tstate->eval_breaker) & _PY_EVAL_EVENTS_MASK) { \ |
| if (_Py_HandlePending(tstate) != 0) { \ |
| GOTO_ERROR(error); \ |
| } \ |
| } |
| |
| |
| /* Tuple access macros */ |
| |
| #ifndef Py_DEBUG |
| #define GETITEM(v, i) PyTuple_GET_ITEM((v), (i)) |
| #else |
| static inline PyObject * |
| GETITEM(PyObject *v, Py_ssize_t i) { |
| assert(PyTuple_Check(v)); |
| assert(i >= 0); |
| assert(i < PyTuple_GET_SIZE(v)); |
| return PyTuple_GET_ITEM(v, i); |
| } |
| #endif |
| |
| /* Code access macros */ |
| |
| /* The integer overflow is checked by an assertion below. */ |
| #define INSTR_OFFSET() ((int)(next_instr - _PyCode_CODE(_PyFrame_GetCode(frame)))) |
| #define NEXTOPARG() do { \ |
| _Py_CODEUNIT word = {.cache = FT_ATOMIC_LOAD_UINT16_RELAXED(*(uint16_t*)next_instr)}; \ |
| opcode = word.op.code; \ |
| oparg = word.op.arg; \ |
| } while (0) |
| |
| /* JUMPBY makes the generator identify the instruction as a jump. SKIP_OVER is |
| * for advancing to the next instruction, taking into account cache entries |
| * and skipped instructions. |
| */ |
| #define JUMPBY(x) (next_instr += (x)) |
| #define SKIP_OVER(x) (next_instr += (x)) |
| |
| /* OpCode prediction macros |
| Some opcodes tend to come in pairs thus making it possible to |
| predict the second code when the first is run. For example, |
| COMPARE_OP is often followed by POP_JUMP_IF_FALSE or POP_JUMP_IF_TRUE. |
| |
| Verifying the prediction costs a single high-speed test of a register |
| variable against a constant. If the pairing was good, then the |
| processor's own internal branch predication has a high likelihood of |
| success, resulting in a nearly zero-overhead transition to the |
| next opcode. A successful prediction saves a trip through the eval-loop |
| including its unpredictable switch-case branch. Combined with the |
| processor's internal branch prediction, a successful PREDICT has the |
| effect of making the two opcodes run as if they were a single new opcode |
| with the bodies combined. |
| |
| If collecting opcode statistics, your choices are to either keep the |
| predictions turned-on and interpret the results as if some opcodes |
| had been combined or turn-off predictions so that the opcode frequency |
| counter updates for both opcodes. |
| |
| Opcode prediction is disabled with threaded code, since the latter allows |
| the CPU to record separate branch prediction information for each |
| opcode. |
| |
| */ |
| |
| #define PREDICT_ID(op) PRED_##op |
| #define PREDICTED(op) PREDICT_ID(op): |
| |
| |
| /* Stack manipulation macros */ |
| |
| /* The stack can grow at most MAXINT deep, as co_nlocals and |
| co_stacksize are ints. */ |
| #define STACK_LEVEL() ((int)(stack_pointer - _PyFrame_Stackbase(frame))) |
| #define STACK_SIZE() (_PyFrame_GetCode(frame)->co_stacksize) |
| #define EMPTY() (STACK_LEVEL() == 0) |
| #define TOP() (stack_pointer[-1]) |
| #define SECOND() (stack_pointer[-2]) |
| #define THIRD() (stack_pointer[-3]) |
| #define FOURTH() (stack_pointer[-4]) |
| #define PEEK(n) (stack_pointer[-(n)]) |
| #define POKE(n, v) (stack_pointer[-(n)] = (v)) |
| #define SET_TOP(v) (stack_pointer[-1] = (v)) |
| #define SET_SECOND(v) (stack_pointer[-2] = (v)) |
| #define BASIC_STACKADJ(n) (stack_pointer += n) |
| #define BASIC_PUSH(v) (*stack_pointer++ = (v)) |
| #define BASIC_POP() (*--stack_pointer) |
| |
| #ifdef Py_DEBUG |
| #define PUSH(v) do { \ |
| BASIC_PUSH(v); \ |
| assert(STACK_LEVEL() <= STACK_SIZE()); \ |
| } while (0) |
| #define POP() (assert(STACK_LEVEL() > 0), BASIC_POP()) |
| #define STACK_GROW(n) do { \ |
| assert(n >= 0); \ |
| BASIC_STACKADJ(n); \ |
| assert(STACK_LEVEL() <= STACK_SIZE()); \ |
| } while (0) |
| #define STACK_SHRINK(n) do { \ |
| assert(n >= 0); \ |
| assert(STACK_LEVEL() >= n); \ |
| BASIC_STACKADJ(-(n)); \ |
| } while (0) |
| #else |
| #define PUSH(v) BASIC_PUSH(v) |
| #define POP() BASIC_POP() |
| #define STACK_GROW(n) BASIC_STACKADJ(n) |
| #define STACK_SHRINK(n) BASIC_STACKADJ(-(n)) |
| #endif |
| |
| |
| /* Data access macros */ |
| #define FRAME_CO_CONSTS (_PyFrame_GetCode(frame)->co_consts) |
| #define FRAME_CO_NAMES (_PyFrame_GetCode(frame)->co_names) |
| |
| /* Local variable macros */ |
| |
| #define LOCALS_ARRAY (frame->localsplus) |
| #define GETLOCAL(i) (frame->localsplus[i]) |
| |
| /* The SETLOCAL() macro must not DECREF the local variable in-place and |
| then store the new value; it must copy the old value to a temporary |
| value, then store the new value, and then DECREF the temporary value. |
| This is because it is possible that during the DECREF the frame is |
| accessed by other code (e.g. a __del__ method or gc.collect()) and the |
| variable would be pointing to already-freed memory. */ |
| #define SETLOCAL(i, value) do { PyObject *tmp = GETLOCAL(i); \ |
| GETLOCAL(i) = value; \ |
| Py_XDECREF(tmp); } while (0) |
| |
| #define GO_TO_INSTRUCTION(op) goto PREDICT_ID(op) |
| |
| #ifdef Py_STATS |
| #define UPDATE_MISS_STATS(INSTNAME) \ |
| do { \ |
| STAT_INC(opcode, miss); \ |
| STAT_INC((INSTNAME), miss); \ |
| /* The counter is always the first cache entry: */ \ |
| if (ADAPTIVE_COUNTER_TRIGGERS(next_instr->cache)) { \ |
| STAT_INC((INSTNAME), deopt); \ |
| } \ |
| } while (0) |
| #else |
| #define UPDATE_MISS_STATS(INSTNAME) ((void)0) |
| #endif |
| |
| #define DEOPT_IF(COND, INSTNAME) \ |
| if ((COND)) { \ |
| /* This is only a single jump on release builds! */ \ |
| UPDATE_MISS_STATS((INSTNAME)); \ |
| assert(_PyOpcode_Deopt[opcode] == (INSTNAME)); \ |
| GO_TO_INSTRUCTION(INSTNAME); \ |
| } |
| |
| |
| #define GLOBALS() frame->f_globals |
| #define BUILTINS() frame->f_builtins |
| #define LOCALS() frame->f_locals |
| #define CONSTS() _PyFrame_GetCode(frame)->co_consts |
| #define NAMES() _PyFrame_GetCode(frame)->co_names |
| |
| #define DTRACE_FUNCTION_ENTRY() \ |
| if (PyDTrace_FUNCTION_ENTRY_ENABLED()) { \ |
| dtrace_function_entry(frame); \ |
| } |
| |
| /* This takes a uint16_t instead of a _Py_BackoffCounter, |
| * because it is used directly on the cache entry in generated code, |
| * which is always an integral type. */ |
| #define ADAPTIVE_COUNTER_TRIGGERS(COUNTER) \ |
| backoff_counter_triggers(forge_backoff_counter((COUNTER))) |
| |
| #ifdef Py_GIL_DISABLED |
| #define ADVANCE_ADAPTIVE_COUNTER(COUNTER) \ |
| do { \ |
| /* gh-115999 tracks progress on addressing this. */ \ |
| static_assert(0, "The specializing interpreter is not yet thread-safe"); \ |
| } while (0); |
| #define PAUSE_ADAPTIVE_COUNTER(COUNTER) ((void)COUNTER) |
| #else |
| #define ADVANCE_ADAPTIVE_COUNTER(COUNTER) \ |
| do { \ |
| (COUNTER) = advance_backoff_counter((COUNTER)); \ |
| } while (0); |
| |
| #define PAUSE_ADAPTIVE_COUNTER(COUNTER) \ |
| do { \ |
| (COUNTER) = pause_backoff_counter((COUNTER)); \ |
| } while (0); |
| #endif |
| |
| #define UNBOUNDLOCAL_ERROR_MSG \ |
| "cannot access local variable '%s' where it is not associated with a value" |
| #define UNBOUNDFREE_ERROR_MSG \ |
| "cannot access free variable '%s' where it is not associated with a value" \ |
| " in enclosing scope" |
| #define NAME_ERROR_MSG "name '%.200s' is not defined" |
| |
| #define DECREF_INPUTS_AND_REUSE_FLOAT(left, right, dval, result) \ |
| do { \ |
| if (Py_REFCNT(left) == 1) { \ |
| ((PyFloatObject *)left)->ob_fval = (dval); \ |
| _Py_DECREF_SPECIALIZED(right, _PyFloat_ExactDealloc);\ |
| result = (left); \ |
| } \ |
| else if (Py_REFCNT(right) == 1) {\ |
| ((PyFloatObject *)right)->ob_fval = (dval); \ |
| _Py_DECREF_NO_DEALLOC(left); \ |
| result = (right); \ |
| }\ |
| else { \ |
| result = PyFloat_FromDouble(dval); \ |
| if ((result) == NULL) GOTO_ERROR(error); \ |
| _Py_DECREF_NO_DEALLOC(left); \ |
| _Py_DECREF_NO_DEALLOC(right); \ |
| } \ |
| } while (0) |
| |
| // If a trace function sets a new f_lineno and |
| // *then* raises, we use the destination when searching |
| // for an exception handler, displaying the traceback, and so on |
| #define INSTRUMENTED_JUMP(src, dest, event) \ |
| do { \ |
| if (tstate->tracing) {\ |
| next_instr = dest; \ |
| } else { \ |
| _PyFrame_SetStackPointer(frame, stack_pointer); \ |
| next_instr = _Py_call_instrumentation_jump(tstate, event, frame, src, dest); \ |
| stack_pointer = _PyFrame_GetStackPointer(frame); \ |
| if (next_instr == NULL) { \ |
| next_instr = (dest)+1; \ |
| goto error; \ |
| } \ |
| } \ |
| } while (0); |
| |
| |
| // GH-89279: Force inlining by using a macro. |
| #if defined(_MSC_VER) && SIZEOF_INT == 4 |
| #define _Py_atomic_load_relaxed_int32(ATOMIC_VAL) (assert(sizeof((ATOMIC_VAL)->_value) == 4), *((volatile int*)&((ATOMIC_VAL)->_value))) |
| #else |
| #define _Py_atomic_load_relaxed_int32(ATOMIC_VAL) _Py_atomic_load_relaxed(ATOMIC_VAL) |
| #endif |
| |
| static inline int _Py_EnterRecursivePy(PyThreadState *tstate) { |
| return (tstate->py_recursion_remaining-- <= 0) && |
| _Py_CheckRecursiveCallPy(tstate); |
| } |
| |
| static inline void _Py_LeaveRecursiveCallPy(PyThreadState *tstate) { |
| tstate->py_recursion_remaining++; |
| } |
| |
| /* Implementation of "macros" that modify the instruction pointer, |
| * stack pointer, or frame pointer. |
| * These need to treated differently by tier 1 and 2. |
| * The Tier 1 version is here; Tier 2 is inlined in ceval.c. */ |
| |
| #define LOAD_IP(OFFSET) do { \ |
| next_instr = frame->instr_ptr + (OFFSET); \ |
| } while (0) |
| |
| /* There's no STORE_IP(), it's inlined by the code generator. */ |
| |
| #define LOAD_SP() \ |
| stack_pointer = _PyFrame_GetStackPointer(frame); |
| |
| /* Tier-switching macros. */ |
| |
| #ifdef _Py_JIT |
| #define GOTO_TIER_TWO(EXECUTOR) \ |
| do { \ |
| OPT_STAT_INC(traces_executed); \ |
| jit_func jitted = (EXECUTOR)->jit_code; \ |
| next_instr = jitted(frame, stack_pointer, tstate); \ |
| Py_DECREF(tstate->previous_executor); \ |
| tstate->previous_executor = NULL; \ |
| frame = tstate->current_frame; \ |
| if (next_instr == NULL) { \ |
| goto resume_with_error; \ |
| } \ |
| stack_pointer = _PyFrame_GetStackPointer(frame); \ |
| DISPATCH(); \ |
| } while (0) |
| #else |
| #define GOTO_TIER_TWO(EXECUTOR) \ |
| do { \ |
| OPT_STAT_INC(traces_executed); \ |
| next_uop = (EXECUTOR)->trace; \ |
| assert(next_uop->opcode == _START_EXECUTOR || next_uop->opcode == _COLD_EXIT); \ |
| goto enter_tier_two; \ |
| } while (0) |
| #endif |
| |
| #define GOTO_TIER_ONE(TARGET) \ |
| do { \ |
| Py_DECREF(tstate->previous_executor); \ |
| tstate->previous_executor = NULL; \ |
| next_instr = target; \ |
| DISPATCH(); \ |
| } while (0) |
| |
| #define CURRENT_OPARG() (next_uop[-1].oparg) |
| |
| #define CURRENT_OPERAND() (next_uop[-1].operand) |
| |
| #define JUMP_TO_JUMP_TARGET() goto jump_to_jump_target |
| #define JUMP_TO_ERROR() goto jump_to_error_target |
| #define GOTO_UNWIND() goto error_tier_two |
| #define EXIT_TO_TRACE() goto exit_to_trace |
| #define EXIT_TO_TIER1() goto exit_to_tier1 |
| #define EXIT_TO_TIER1_DYNAMIC() goto exit_to_tier1_dynamic; |
