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bpo-44337: Port LOAD_ATTR to PEP 659 adaptive interpreter (GH-26595)

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* Specialize LOAD_ATTR with  LOAD_ATTR_SLOT and LOAD_ATTR_SPLIT_KEYS

* Move dict-common.h to internal/pycore_dict.h

* Add LOAD_ATTR_WITH_HINT specialized opcode.

* Quicken in function if loopy

* Specialize LOAD_ATTR for module attributes.

* Add specialization stats
This commit is contained in:
Mark Shannon 2021-06-10 08:46:01 +01:00 • committed by GitHub
parent 309ab61602
commit e117c02837
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GPG key ID: 4AEE18F83AFDEB23
14 changed files with 511 additions and 221 deletions
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354
Python/ceval.c
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@ -16,6 +16,7 @@
#include "pycore_code.h" // _PyCode_InitOpcache()
#include "pycore_initconfig.h" // _PyStatus_OK()
#include "pycore_object.h" // _PyObject_GC_TRACK()
#include "pycore_moduleobject.h"
#include "pycore_pyerrors.h" // _PyErr_Fetch()
#include "pycore_pylifecycle.h" // _PyErr_Print()
#include "pycore_pymem.h" // _PyMem_IsPtrFreed()
@ -24,6 +25,7 @@
#include "pycore_tuple.h" // _PyTuple_ITEMS()
#include "code.h"
#include "pycore_dict.h"
#include "dictobject.h"
#include "frameobject.h"
#include "pycore_frame.h"
@ -1554,8 +1556,15 @@ eval_frame_handle_pending(PyThreadState *tstate)
#define OPCACHE_STAT_ATTR_DEOPT()
#define OPCACHE_STAT_ATTR_TOTAL()
#define JUMP_TO_INSTRUCTION(op) goto PREDICT_ID(op)
#define GET_CACHE() \
_GetSpecializedCacheEntryForInstruction(first_instr, INSTR_OFFSET(), oparg)
#endif
#define DEOPT_IF(cond, instname) if (cond) { goto instname ## _miss; }
#define GLOBALS() specials[FRAME_SPECIALS_GLOBALS_OFFSET]
#define BUILTINS() specials[FRAME_SPECIALS_BUILTINS_OFFSET]
#define LOCALS() specials[FRAME_SPECIALS_LOCALS_OFFSET]
@ -1574,7 +1583,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
int lastopcode = 0;
#endif
PyObject **stack_pointer; /* Next free slot in value stack */
const _Py_CODEUNIT *next_instr;
_Py_CODEUNIT *next_instr;
int opcode; /* Current opcode */
int oparg; /* Current opcode argument, if any */
PyObject **localsplus, **specials;
@ -1582,7 +1591,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
_Py_atomic_int * const eval_breaker = &tstate->interp->ceval.eval_breaker;
PyCodeObject *co;
const _Py_CODEUNIT *first_instr;
_Py_CODEUNIT *first_instr;
PyObject *names;
PyObject *consts;
_PyOpcache *co_opcache;
@ -3443,196 +3452,129 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
}
case TARGET(LOAD_ATTR): {
PREDICTED(LOAD_ATTR);
PyObject *name = GETITEM(names, oparg);
PyObject *owner = TOP();
PyTypeObject *type = Py_TYPE(owner);
PyObject *res;
PyObject **dictptr;
PyObject *dict;
_PyOpCodeOpt_LoadAttr *la;
OPCACHE_STAT_ATTR_TOTAL();
OPCACHE_CHECK();
if (co_opcache != NULL && PyType_HasFeature(type, Py_TPFLAGS_VALID_VERSION_TAG))
{
if (co_opcache->optimized > 0) {
// Fast path -- cache hit makes LOAD_ATTR ~30% faster.
la = &co_opcache->u.la;
if (la->type == type && la->tp_version_tag == type->tp_version_tag)
{
// Hint >= 0 is a dict index; hint == -1 is a dict miss.
// Hint < -1 is an inverted slot offset: offset is strictly > 0,
// so ~offset is strictly < -1 (assuming 2's complement).
if (la->hint < -1) {
// Even faster path -- slot hint.
Py_ssize_t offset = ~la->hint;
// fprintf(stderr, "Using hint for offset %zd\n", offset);
char *addr = (char *)owner + offset;
res = *(PyObject **)addr;
if (res != NULL) {
Py_INCREF(res);
SET_TOP(res);
Py_DECREF(owner);
DISPATCH();
}
// Else slot is NULL. Fall through to slow path to raise AttributeError(name).
// Don't DEOPT, since the slot is still there.
} else {
// Fast path for dict.
assert(type->tp_dict != NULL);
assert(type->tp_dictoffset > 0);
dictptr = (PyObject **) ((char *)owner + type->tp_dictoffset);
dict = *dictptr;
if (dict != NULL && PyDict_CheckExact(dict)) {
Py_ssize_t hint = la->hint;
Py_INCREF(dict);
res = NULL;
assert(!_PyErr_Occurred(tstate));
la->hint = _PyDict_GetItemHint((PyDictObject*)dict, name, hint, &res);
if (res != NULL) {
assert(la->hint >= 0);
if (la->hint == hint && hint >= 0) {
// Our hint has helped -- cache hit.
OPCACHE_STAT_ATTR_HIT();
} else {
// The hint we provided didn't work.
// Maybe next time?
OPCACHE_MAYBE_DEOPT_LOAD_ATTR();
}
Py_INCREF(res);
SET_TOP(res);
Py_DECREF(owner);
Py_DECREF(dict);
DISPATCH();
}
else {
_PyErr_Clear(tstate);
// This attribute can be missing sometimes;
// we don't want to optimize this lookup.
OPCACHE_DEOPT_LOAD_ATTR();
Py_DECREF(dict);
}
}
else {
// There is no dict, or __dict__ doesn't satisfy PyDict_CheckExact.
OPCACHE_DEOPT_LOAD_ATTR();
}
}
}
else {
// The type of the object has either been updated,
// or is different. Maybe it will stabilize?
OPCACHE_MAYBE_DEOPT_LOAD_ATTR();
}
OPCACHE_STAT_ATTR_MISS();
}
if (co_opcache != NULL && // co_opcache can be NULL after a DEOPT() call.
type->tp_getattro == PyObject_GenericGetAttr)
{
if (type->tp_dict == NULL) {
if (PyType_Ready(type) < 0) {
Py_DECREF(owner);
SET_TOP(NULL);
goto error;
}
}
PyObject *descr = _PyType_Lookup(type, name);
if (descr != NULL) {
// We found an attribute with a data-like descriptor.
PyTypeObject *dtype = Py_TYPE(descr);
if (dtype == &PyMemberDescr_Type) { // It's a slot
PyMemberDescrObject *member = (PyMemberDescrObject *)descr;
struct PyMemberDef *dmem = member->d_member;
if (dmem->type == T_OBJECT_EX) {
Py_ssize_t offset = dmem->offset;
assert(offset > 0); // 0 would be confused with dict hint == -1 (miss).
if (co_opcache->optimized == 0) {
// First time we optimize this opcode.
OPCACHE_STAT_ATTR_OPT();
co_opcache->optimized = OPCODE_CACHE_MAX_TRIES;
// fprintf(stderr, "Setting hint for %s, offset %zd\n", dmem->name, offset);
}
la = &co_opcache->u.la;
la->type = type;
la->tp_version_tag = type->tp_version_tag;
la->hint = ~offset;
char *addr = (char *)owner + offset;
res = *(PyObject **)addr;
if (res != NULL) {
Py_INCREF(res);
Py_DECREF(owner);
SET_TOP(res);
DISPATCH();
}
// Else slot is NULL. Fall through to slow path to raise AttributeError(name).
}
// Else it's a slot of a different type. We don't handle those.
}
// Else it's some other kind of descriptor that we don't handle.
OPCACHE_DEOPT_LOAD_ATTR();
}
else if (type->tp_dictoffset > 0) {
// We found an instance with a __dict__.
dictptr = (PyObject **) ((char *)owner + type->tp_dictoffset);
dict = *dictptr;
if (dict != NULL && PyDict_CheckExact(dict)) {
Py_INCREF(dict);
res = NULL;
assert(!_PyErr_Occurred(tstate));
Py_ssize_t hint = _PyDict_GetItemHint((PyDictObject*)dict, name, -1, &res);
if (res != NULL) {
Py_INCREF(res);
Py_DECREF(dict);
Py_DECREF(owner);
SET_TOP(res);
if (co_opcache->optimized == 0) {
// First time we optimize this opcode.
OPCACHE_STAT_ATTR_OPT();
co_opcache->optimized = OPCODE_CACHE_MAX_TRIES;
}
la = &co_opcache->u.la;
la->type = type;
la->tp_version_tag = type->tp_version_tag;
assert(hint >= 0);
la->hint = hint;
DISPATCH();
}
else {
_PyErr_Clear(tstate);
}
Py_DECREF(dict);
} else {
// There is no dict, or __dict__ doesn't satisfy PyDict_CheckExact.
OPCACHE_DEOPT_LOAD_ATTR();
}
} else {
// The object's class does not have a tp_dictoffset we can use.
OPCACHE_DEOPT_LOAD_ATTR();
}
} else if (type->tp_getattro != PyObject_GenericGetAttr) {
OPCACHE_DEOPT_LOAD_ATTR();
}
PyObject *res = PyObject_GetAttr(owner, name);
if (res == NULL) {
goto error;
}
// Slow path.
res = PyObject_GetAttr(owner, name);
Py_DECREF(owner);
SET_TOP(res);
if (res == NULL)
goto error;
DISPATCH();
}
case TARGET(LOAD_ATTR_ADAPTIVE): {
SpecializedCacheEntry *cache = GET_CACHE();
if (cache->adaptive.counter == 0) {
PyObject *owner = TOP();
PyObject *name = GETITEM(names, cache->adaptive.original_oparg);
next_instr--;
if (_Py_Specialize_LoadAttr(owner, next_instr, name, cache) < 0) {
goto error;
}
DISPATCH();
}
else {
STAT_INC(loadattr_deferred);
cache->adaptive.counter--;
oparg = cache->adaptive.original_oparg;
JUMP_TO_INSTRUCTION(LOAD_ATTR);
}
}
case TARGET(LOAD_ATTR_SPLIT_KEYS): {
PyObject *owner = TOP();
PyObject *res;
PyTypeObject *tp = Py_TYPE(owner);
SpecializedCacheEntry *caches = GET_CACHE();
_PyAdaptiveEntry *cache0 = &caches[0].adaptive;
_PyLoadAttrCache *cache1 = &caches[-1].load_attr;
assert(cache1->tp_version != 0);
DEOPT_IF(tp->tp_version_tag != cache1->tp_version, LOAD_ATTR);
assert(tp->tp_dictoffset > 0);
PyDictObject *dict = *(PyDictObject **)(((char *)owner) + tp->tp_dictoffset);
DEOPT_IF(dict == NULL, LOAD_ATTR);
assert(PyDict_CheckExact((PyObject *)dict));
DEOPT_IF(dict->ma_keys->dk_version != cache1->dk_version_or_hint, LOAD_ATTR);
res = dict->ma_values[cache0->index];
DEOPT_IF(res == NULL, LOAD_ATTR);
STAT_INC(loadattr_hit);
record_cache_hit(cache0);
STAT_INC(loadattr_hit);
Py_INCREF(res);
SET_TOP(res);
Py_DECREF(owner);
DISPATCH();
}
case TARGET(LOAD_ATTR_MODULE): {
PyObject *owner = TOP();
PyObject *res;
SpecializedCacheEntry *caches = GET_CACHE();
_PyAdaptiveEntry *cache0 = &caches[0].adaptive;
_PyLoadAttrCache *cache1 = &caches[-1].load_attr;
DEOPT_IF(!PyModule_CheckExact(owner), LOAD_ATTR);
PyDictObject *dict = (PyDictObject *)((PyModuleObject *)owner)->md_dict;
DEOPT_IF(dict->ma_keys->dk_version != cache1->dk_version_or_hint, LOAD_ATTR);
assert(dict->ma_keys->dk_kind == DICT_KEYS_UNICODE);
assert(cache0->index < dict->ma_keys->dk_nentries);
PyDictKeyEntry *ep = DK_ENTRIES(dict->ma_keys) + cache0->index;
res = ep->me_value;
DEOPT_IF(res == NULL, LOAD_ATTR);
STAT_INC(loadattr_hit);
record_cache_hit(cache0);
Py_INCREF(res);
SET_TOP(res);
Py_DECREF(owner);
DISPATCH();
}
case TARGET(LOAD_ATTR_WITH_HINT): {
PyObject *owner = TOP();
PyObject *res;
PyTypeObject *tp = Py_TYPE(owner);
SpecializedCacheEntry *caches = GET_CACHE();
_PyAdaptiveEntry *cache0 = &caches[0].adaptive;
_PyLoadAttrCache *cache1 = &caches[-1].load_attr;
assert(cache1->tp_version != 0);
DEOPT_IF(tp->tp_version_tag != cache1->tp_version, LOAD_ATTR);
assert(tp->tp_dictoffset > 0);
PyDictObject *dict = *(PyDictObject **)(((char *)owner) + tp->tp_dictoffset);
DEOPT_IF(dict == NULL, LOAD_ATTR);
assert(PyDict_CheckExact((PyObject *)dict));
PyObject *name = GETITEM(names, cache0->original_oparg);
uint32_t hint = cache1->dk_version_or_hint;
DEOPT_IF(hint >= dict->ma_keys->dk_nentries, LOAD_ATTR);
PyDictKeyEntry *ep = DK_ENTRIES(dict->ma_keys) + hint;
DEOPT_IF(ep->me_key != name, LOAD_ATTR);
res = ep->me_value;
DEOPT_IF(res == NULL, LOAD_ATTR);
STAT_INC(loadattr_hit);
record_cache_hit(cache0);
Py_INCREF(res);
SET_TOP(res);
Py_DECREF(owner);
DISPATCH();
}
case TARGET(LOAD_ATTR_SLOT): {
PyObject *owner = TOP();
PyObject *res;
PyTypeObject *tp = Py_TYPE(owner);
SpecializedCacheEntry *caches = GET_CACHE();
_PyAdaptiveEntry *cache0 = &caches[0].adaptive;
_PyLoadAttrCache *cache1 = &caches[-1].load_attr;
assert(cache1->tp_version != 0);
DEOPT_IF(tp->tp_version_tag != cache1->tp_version, LOAD_ATTR);
char *addr = (char *)owner + cache0->index;
res = *(PyObject **)addr;
DEOPT_IF(res == NULL, LOAD_ATTR);
STAT_INC(loadattr_hit);
record_cache_hit(cache0);
Py_INCREF(res);
SET_TOP(res);
Py_DECREF(owner);
DISPATCH();
}
@ -3879,6 +3821,27 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
case TARGET(JUMP_ABSOLUTE): {
PREDICTED(JUMP_ABSOLUTE);
if (oparg < INSTR_OFFSET()) {
/* Increment the warmup counter and quicken if warm enough
* _Py_Quicken is idempotent so we don't worry about overflow */
if (!PyCodeObject_IsWarmedUp(co)) {
PyCodeObject_IncrementWarmup(co);
if (PyCodeObject_IsWarmedUp(co)) {
if (_Py_Quicken(co)) {
goto error;
}
int nexti = INSTR_OFFSET();
first_instr = co->co_firstinstr;
next_instr = first_instr + nexti;
}
}
}
JUMPTO(oparg);
CHECK_EVAL_BREAKER();
DISPATCH();
}
case TARGET(JUMP_ABSOLUTE_QUICK): {
JUMPTO(oparg);
CHECK_EVAL_BREAKER();
DISPATCH();
@ -4494,6 +4457,22 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
or goto error. */
Py_UNREACHABLE();
/* Cache misses */
LOAD_ATTR_miss:
{
STAT_INC(loadattr_miss);
_PyAdaptiveEntry *cache = &GET_CACHE()->adaptive;
record_cache_miss(cache);
if (too_many_cache_misses(cache)) {
next_instr[-1] = _Py_MAKECODEUNIT(LOAD_ATTR_ADAPTIVE, _Py_OPARG(next_instr[-1]));
STAT_INC(loadattr_deopt);
cache_backoff(cache);
}
oparg = cache->original_oparg;
JUMP_TO_INSTRUCTION(LOAD_ATTR);
}
error:
/* Double-check exception status. */
#ifdef NDEBUG
@ -4515,6 +4494,7 @@ error:
call_exc_trace(tstate->c_tracefunc, tstate->c_traceobj,
tstate, f, &trace_info);
}
exception_unwind:
f->f_state = FRAME_UNWINDING;
/* We can't use f->f_lasti here, as RERAISE may have set it */