GH-118095: Unify the behavior of tier 2 FOR_ITER branch micro-ops (GH-118420)

* Target _FOR_ITER_TIER_TWO at POP_TOP following the matching END_FOR

* Modify _GUARD_NOT_EXHAUSTED_RANGE, _GUARD_NOT_EXHAUSTED_LIST and _GUARD_NOT_EXHAUSTED_TUPLE so that they also target the POP_TOP following the matching END_FOR
This commit is contained in:
Mark Shannon 2024-05-02 16:17:59 +01:00 committed by GitHub
parent 9789440de3
commit 72867c962c
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
5 changed files with 56 additions and 21 deletions

View File

@ -2610,9 +2610,7 @@ dummy_func(
_PyErr_Clear(tstate);
}
/* iterator ended normally */
Py_DECREF(iter);
STACK_SHRINK(1);
/* The translator sets the deopt target just past END_FOR */
/* The translator sets the deopt target just past the matching END_FOR */
DEOPT_IF(true);
}
// Common case: no jump, leave it to the code generator

View File

@ -2664,9 +2664,7 @@
_PyErr_Clear(tstate);
}
/* iterator ended normally */
Py_DECREF(iter);
STACK_SHRINK(1);
/* The translator sets the deopt target just past END_FOR */
/* The translator sets the deopt target just past the matching END_FOR */
if (true) {
UOP_STAT_INC(uopcode, miss);
JUMP_TO_JUMP_TARGET();

View File

@ -23,6 +23,19 @@
#define MAX_EXECUTORS_SIZE 256
#ifdef Py_DEBUG
static int
base_opcode(PyCodeObject *code, int offset)
{
int opcode = _Py_GetBaseOpcode(code, offset);
if (opcode == ENTER_EXECUTOR) {
int oparg = _PyCode_CODE(code)[offset].op.arg;
_PyExecutorObject *ex = code->co_executors->executors[oparg];
return ex->vm_data.opcode;
}
return opcode;
}
#endif
static bool
has_space_for_executor(PyCodeObject *code, _Py_CODEUNIT *instr)
@ -445,6 +458,14 @@ _PyUOp_Replacements[MAX_UOP_ID + 1] = {
[_FOR_ITER] = _FOR_ITER_TIER_TWO,
};
static const uint8_t
is_for_iter_test[MAX_UOP_ID + 1] = {
[_GUARD_NOT_EXHAUSTED_RANGE] = 1,
[_GUARD_NOT_EXHAUSTED_LIST] = 1,
[_GUARD_NOT_EXHAUSTED_TUPLE] = 1,
[_FOR_ITER_TIER_TWO] = 1,
};
static const uint16_t
BRANCH_TO_GUARD[4][2] = {
[POP_JUMP_IF_FALSE - POP_JUMP_IF_FALSE][0] = _GUARD_IS_TRUE_POP,
@ -594,7 +615,6 @@ top: // Jump here after _PUSH_FRAME or likely branches
uint32_t opcode = instr->op.code;
uint32_t oparg = instr->op.arg;
uint32_t extended = 0;
DPRINTF(2, "%d: %s(%d)\n", target, _PyOpcode_OpName[opcode], oparg);
@ -608,7 +628,6 @@ top: // Jump here after _PUSH_FRAME or likely branches
if (opcode == EXTENDED_ARG) {
instr++;
extended = 1;
opcode = instr->op.code;
oparg = (oparg << 8) | instr->op.arg;
if (opcode == EXTENDED_ARG) {
@ -772,12 +791,15 @@ top: // Jump here after _PUSH_FRAME or likely branches
case OPARG_REPLACED:
uop = _PyUOp_Replacements[uop];
assert(uop != 0);
if (uop == _FOR_ITER_TIER_TWO) {
target += 1 + INLINE_CACHE_ENTRIES_FOR_ITER + oparg + 2 + extended;
assert(_PyCode_CODE(code)[target-2].op.code == END_FOR ||
_PyCode_CODE(code)[target-2].op.code == INSTRUMENTED_END_FOR);
assert(_PyCode_CODE(code)[target-1].op.code == POP_TOP);
#ifdef Py_DEBUG
{
uint32_t next_inst = target + 1 + INLINE_CACHE_ENTRIES_FOR_ITER + (oparg > 255);
uint32_t jump_target = next_inst + oparg;
assert(base_opcode(code, jump_target) == END_FOR ||
base_opcode(code, jump_target) == INSTRUMENTED_END_FOR);
assert(base_opcode(code, jump_target+1) == POP_TOP);
}
#endif
break;
default:
fprintf(stderr,
@ -1000,10 +1022,18 @@ prepare_for_execution(_PyUOpInstruction *buffer, int length)
if (_PyUop_Flags[opcode] & (HAS_EXIT_FLAG | HAS_DEOPT_FLAG)) {
uint16_t exit_op = (_PyUop_Flags[opcode] & HAS_EXIT_FLAG) ?
_SIDE_EXIT : _DEOPT;
if (target != current_jump_target || current_exit_op != exit_op) {
make_exit(&buffer[next_spare], exit_op, target);
int32_t jump_target = target;
if (is_for_iter_test[opcode]) {
/* Target the POP_TOP immediately after the END_FOR,
* leaving only the iterator on the stack. */
int extended_arg = inst->oparg > 255;
int32_t next_inst = target + 1 + INLINE_CACHE_ENTRIES_FOR_ITER + extended_arg;
jump_target = next_inst + inst->oparg + 1;
}
if (jump_target != current_jump_target || current_exit_op != exit_op) {
make_exit(&buffer[next_spare], exit_op, jump_target);
current_exit_op = exit_op;
current_jump_target = target;
current_jump_target = jump_target;
current_jump = next_spare;
next_spare++;
}

View File

@ -164,19 +164,26 @@ _Py_uop_sym_set_const(_Py_UopsSymbol *sym, PyObject *const_val)
return true;
}
bool
_Py_uop_sym_set_null(_Py_UopsSymbol *sym)
{
if (_Py_uop_sym_is_not_null(sym)) {
sym_set_bottom(sym);
return false;
}
sym_set_flag(sym, IS_NULL);
return !_Py_uop_sym_is_bottom(sym);
return true;
}
bool
_Py_uop_sym_set_non_null(_Py_UopsSymbol *sym)
{
if (_Py_uop_sym_is_null(sym)) {
sym_set_bottom(sym);
return false;
}
sym_set_flag(sym, NOT_NULL);
return !_Py_uop_sym_is_bottom(sym);
return true;
}

View File

@ -215,6 +215,7 @@ print_gc_stats(FILE *out, GCStats *stats)
}
}
#ifdef _Py_TIER2
static void
print_histogram(FILE *out, const char *name, uint64_t hist[_Py_UOP_HIST_SIZE])
{
@ -249,7 +250,6 @@ print_optimization_stats(FILE *out, OptimizationStats *stats)
stats->optimizer_failure_reason_no_memory);
fprintf(out, "Optimizer remove globals builtins changed: %" PRIu64 "\n", stats->remove_globals_builtins_changed);
fprintf(out, "Optimizer remove globals incorrect keys: %" PRIu64 "\n", stats->remove_globals_incorrect_keys);
for (int i = 0; i <= MAX_UOP_ID; i++) {
if (stats->opcode[i].execution_count) {
fprintf(out, "uops[%s].execution_count : %" PRIu64 "\n", _PyUOpName(i), stats->opcode[i].execution_count);
@ -258,7 +258,6 @@ print_optimization_stats(FILE *out, OptimizationStats *stats)
fprintf(out, "uops[%s].specialization.miss : %" PRIu64 "\n", _PyUOpName(i), stats->opcode[i].miss);
}
}
for (int i = 0; i < 256; i++) {
if (stats->unsupported_opcode[i]) {
fprintf(
@ -289,6 +288,7 @@ print_optimization_stats(FILE *out, OptimizationStats *stats)
}
}
}
#endif
static void
print_rare_event_stats(FILE *out, RareEventStats *stats)
@ -309,7 +309,9 @@ print_stats(FILE *out, PyStats *stats)
print_call_stats(out, &stats->call_stats);
print_object_stats(out, &stats->object_stats);
print_gc_stats(out, stats->gc_stats);
#ifdef _Py_TIER2
print_optimization_stats(out, &stats->optimization_stats);
#endif
print_rare_event_stats(out, &stats->rare_event_stats);
}