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Merged
markshannon merged 10 commits into from
Oct 14, 2021
Merged

bpo-45367: Specialize BINARY_MULTIPLY #28727

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3c85756
Implement specialized opcodes for BINARY_MULTIPLY
sweeneyde Oct 5, 2021
300a0ca
📜🤖 Added by blurb_it.
blurb-it[bot] Oct 5, 2021
d266912
Resolve merge conflicts
sweeneyde Oct 5, 2021
c64540a
Apply changes from code review
sweeneyde Oct 5, 2021
5a44ecc
Allow float/int mixtures is BINARY_MULTIPLY_FLOAT
sweeneyde Oct 5, 2021
aea424e
Minor cleanups and comments
sweeneyde Oct 5, 2021
37d3716
Revert the float/int mixtures
sweeneyde Oct 7, 2021
903ff9c
typo: sum --> prod
sweeneyde Oct 7, 2021
7aecc97
Merge branch 'main' into multiply
sweeneyde Oct 10, 2021
31c3bb9
Merge main into multiply
sweeneyde Oct 13, 2021
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3 changes: 2 additions & 1 deletion Include/internal/pycore_code.h
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Original file line numberDiff line numberDiff line change
Expand Up@@ -307,7 +307,8 @@ int _Py_Specialize_StoreAttr(PyObject *owner, _Py_CODEUNIT *instr, PyObject *nam
int _Py_Specialize_LoadGlobal(PyObject *globals, PyObject *builtins, _Py_CODEUNIT *instr, PyObject *name, SpecializedCacheEntry *cache);
int _Py_Specialize_LoadMethod(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name, SpecializedCacheEntry *cache);
int _Py_Specialize_BinarySubscr(PyObject *sub, PyObject *container, _Py_CODEUNIT *instr);
int _Py_Specialize_BinaryAdd(PyObject *sub, PyObject *container, _Py_CODEUNIT *instr);
int _Py_Specialize_BinaryAdd(PyObject *left, PyObject *right, _Py_CODEUNIT *instr);
int _Py_Specialize_BinaryMultiply(PyObject *left, PyObject *right, _Py_CODEUNIT *instr);

#define PRINT_SPECIALIZATION_STATS 0
#define PRINT_SPECIALIZATION_STATS_DETAILED 0
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1 change: 1 addition & 0 deletions Include/internal/pycore_long.h
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Expand Up@@ -35,6 +35,7 @@ static inline PyObject* _PyLong_GetOne(void)
{return __PyLong_GetSmallInt_internal(1)}

PyObject *_PyLong_Add(PyLongObject *left, PyLongObject *right);
PyObject *_PyLong_Multiply(PyLongObject *left, PyLongObject *right);

#ifdef __cplusplus
}
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57 changes: 30 additions & 27 deletions Include/opcode.h
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3 changes: 3 additions & 0 deletions Lib/opcode.py
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Expand Up@@ -225,6 +225,9 @@ def jabs_op(name, op):
"BINARY_ADD_FLOAT",
"BINARY_ADD_UNICODE",
"BINARY_ADD_UNICODE_INPLACE_FAST",
"BINARY_MULTIPLY_ADAPTIVE",
"BINARY_MULTIPLY_INT",
"BINARY_MULTIPLY_FLOAT",
"BINARY_SUBSCR_ADAPTIVE",
"BINARY_SUBSCR_LIST_INT",
"BINARY_SUBSCR_TUPLE_INT",
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1 change: 1 addition & 0 deletions Misc/NEWS.d/next/Core and Builtins/2021-10-05-03-49-07.bpo-45367._astoU.rst
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@@ -0,0 +1 @@
Specialized the ``BINARY_MULTIPLY`` opcode to ``BINARY_MULTIPLY_INT`` and ``BINARY_MULTIPLY_FLOAT`` using the PEP 659 machinery.
13 changes: 9 additions & 4 deletions Objects/longobject.c
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Expand Up@@ -3593,13 +3593,11 @@ k_lopsided_mul(PyLongObject *a, PyLongObject *b)
return NULL;
}

static PyObject *
long_mul(PyLongObject *a, PyLongObject *b)
PyObject *
_PyLong_Multiply(PyLongObject *a, PyLongObject *b)
{
PyLongObject *z;

CHECK_BINOP(a, b);

/* fast path for single-digit multiplication */
if (IS_MEDIUM_VALUE(a) && IS_MEDIUM_VALUE(b)){
stwodigits v = medium_value(a) * medium_value(b);
Expand All@@ -3616,6 +3614,13 @@ long_mul(PyLongObject *a, PyLongObject *b)
return (PyObject *)z;
}

static PyObject *
long_mul(PyLongObject *a, PyLongObject *b)
{
CHECK_BINOP(a, b);
return _PyLong_Multiply(a, b);
}

/* Fast modulo division for single-digit longs. */
static PyObject *
fast_mod(PyLongObject *a, PyLongObject *b)
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62 changes: 61 additions & 1 deletion Python/ceval.c
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Expand Up@@ -1933,14 +1933,73 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, InterpreterFrame *frame, int thr
}

TARGET(BINARY_MULTIPLY){
PREDICTED(BINARY_MULTIPLY);
STAT_INC(BINARY_MULTIPLY, unquickened);
PyObject *right = POP();
PyObject *left = TOP();
PyObject *res = PyNumber_Multiply(left, right);
Py_DECREF(left);
Py_DECREF(right);
SET_TOP(res);
if (res == NULL)
if (res == NULL){
goto error;
}
DISPATCH();
}

TARGET(BINARY_MULTIPLY_ADAPTIVE){
if (oparg == 0){
PyObject *left = SECOND();
PyObject *right = TOP();
next_instr--;
if (_Py_Specialize_BinaryMultiply(left, right, next_instr) < 0){
goto error;
}
DISPATCH();
}
else{
STAT_INC(BINARY_MULTIPLY, deferred);
UPDATE_PREV_INSTR_OPARG(next_instr, oparg - 1);
STAT_DEC(BINARY_MULTIPLY, unquickened);
JUMP_TO_INSTRUCTION(BINARY_MULTIPLY);
}
}

TARGET(BINARY_MULTIPLY_INT){
PyObject *left = SECOND();
PyObject *right = TOP();
DEOPT_IF(!PyLong_CheckExact(left), BINARY_MULTIPLY);
DEOPT_IF(!PyLong_CheckExact(right), BINARY_MULTIPLY);
STAT_INC(BINARY_MULTIPLY, hit);
record_hit_inline(next_instr, oparg);
PyObject *prod = _PyLong_Multiply((PyLongObject *)left, (PyLongObject *)right);
SET_SECOND(prod);
Py_DECREF(right);
Py_DECREF(left);
STACK_SHRINK(1);
if (prod == NULL){
goto error;
}
DISPATCH();
}

TARGET(BINARY_MULTIPLY_FLOAT){
PyObject *left = SECOND();
PyObject *right = TOP();
DEOPT_IF(!PyFloat_CheckExact(left), BINARY_MULTIPLY);
DEOPT_IF(!PyFloat_CheckExact(right), BINARY_MULTIPLY);
STAT_INC(BINARY_MULTIPLY, hit);
record_hit_inline(next_instr, oparg);
double dprod = ((PyFloatObject *)left)->ob_fval *
((PyFloatObject *)right)->ob_fval;
PyObject *prod = PyFloat_FromDouble(dprod);
SET_SECOND(prod);
Py_DECREF(right);
Py_DECREF(left);
STACK_SHRINK(1);
if (prod == NULL){
goto error;
}
DISPATCH();
}

Expand DownExpand Up@@ -4954,6 +5013,7 @@ MISS_WITH_CACHE(LOAD_GLOBAL)
MISS_WITH_CACHE(LOAD_METHOD)
MISS_WITH_OPARG_COUNTER(BINARY_SUBSCR)
MISS_WITH_OPARG_COUNTER(BINARY_ADD)
MISS_WITH_OPARG_COUNTER(BINARY_MULTIPLY)

binary_subscr_dict_error:
{
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44 changes: 22 additions & 22 deletions Python/opcode_targets.h
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33 changes: 33 additions & 0 deletions Python/specialize.c
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Original file line numberDiff line numberDiff line change
Expand Up@@ -124,6 +124,7 @@ _Py_GetSpecializationStats(void){
err += add_stat_dict(stats, LOAD_GLOBAL, "load_global");
err += add_stat_dict(stats, LOAD_METHOD, "load_method");
err += add_stat_dict(stats, BINARY_ADD, "binary_add");
err += add_stat_dict(stats, BINARY_MULTIPLY, "binary_multiply");
err += add_stat_dict(stats, BINARY_SUBSCR, "binary_subscr");
err += add_stat_dict(stats, STORE_ATTR, "store_attr");
if (err < 0){
Expand DownExpand Up@@ -180,6 +181,7 @@ _Py_PrintSpecializationStats(void)
print_stats(out, &_specialization_stats[LOAD_GLOBAL], "load_global");
print_stats(out, &_specialization_stats[LOAD_METHOD], "load_method");
print_stats(out, &_specialization_stats[BINARY_ADD], "binary_add");
print_stats(out, &_specialization_stats[BINARY_MULTIPLY], "binary_multiply");
print_stats(out, &_specialization_stats[BINARY_SUBSCR], "binary_subscr");
print_stats(out, &_specialization_stats[STORE_ATTR], "store_attr");
if (out != stderr){
Expand DownExpand Up@@ -230,6 +232,7 @@ static uint8_t adaptive_opcodes[256] ={
[LOAD_GLOBAL] = LOAD_GLOBAL_ADAPTIVE,
[LOAD_METHOD] = LOAD_METHOD_ADAPTIVE,
[BINARY_ADD] = BINARY_ADD_ADAPTIVE,
[BINARY_MULTIPLY] = BINARY_MULTIPLY_ADAPTIVE,
[BINARY_SUBSCR] = BINARY_SUBSCR_ADAPTIVE,
[STORE_ATTR] = STORE_ATTR_ADAPTIVE,
};
Expand All@@ -240,6 +243,7 @@ static uint8_t cache_requirements[256] ={
[LOAD_GLOBAL] = 2, /* _PyAdaptiveEntry and _PyLoadGlobalCache */
[LOAD_METHOD] = 3, /* _PyAdaptiveEntry, _PyAttrCache and _PyObjectCache */
[BINARY_ADD] = 0,
[BINARY_MULTIPLY] = 0,
[BINARY_SUBSCR] = 0,
[STORE_ATTR] = 2, /* _PyAdaptiveEntry and _PyAttrCache */
};
Expand DownExpand Up@@ -1188,3 +1192,32 @@ _Py_Specialize_BinaryAdd(PyObject *left, PyObject *right, _Py_CODEUNIT *instr)
assert(!PyErr_Occurred());
return 0;
}

int
_Py_Specialize_BinaryMultiply(PyObject *left, PyObject *right, _Py_CODEUNIT *instr)
{
if (!Py_IS_TYPE(left, Py_TYPE(right))){
SPECIALIZATION_FAIL(BINARY_MULTIPLY, SPEC_FAIL_DIFFERENT_TYPES);
goto fail;
}
if (PyLong_CheckExact(left)){
*instr = _Py_MAKECODEUNIT(BINARY_MULTIPLY_INT, saturating_start());
goto success;
}
else if (PyFloat_CheckExact(left)){
*instr = _Py_MAKECODEUNIT(BINARY_MULTIPLY_FLOAT, saturating_start());
goto success;
}
else{
SPECIALIZATION_FAIL(BINARY_MULTIPLY, SPEC_FAIL_OTHER);
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@markshannonmarkshannonOct 5, 2021

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Maybe this should be refined further. In another PR, though.

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@Fidget-SpinnerFidget-SpinnerOct 5, 2021•
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I agree. I don't think it will touch pyperformance, but it seems that in our own test suite almost 10% aren't hits #28727 (comment).

This probably varies wildly, I'd imagine test_string has lots of str * num too.
Oh gosh I just realized I'd read the entire PR as BINARY_ADD not BINARY_MULTIPLY. Please ignore my delusional ramblings.

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@sweeneydesweeneydeOct 5, 2021

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Most of the non-hits are deferred, not specialization failure, so I think that's because the nature of a lot of test code is to only be run once, without many tight loops.

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@Fidget-SpinnerFidget-SpinnerOct 5, 2021•
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Thanks for pointing that out Dennis. I can't believe I missed that :). That means nearly 100% actual specialization on hot code. Hooray!

Off-topic: I've recently wondered if pyperformance is somewhat out of touch (no offence intended to its contributors). Many of its benchmarks (nbody, nqueens, etc.) have been found by the JS folks to not be realistic. The Pyston benchmark suite seems way more comprehensive.

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@markshannonmarkshannonOct 5, 2021•
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"deferred" means that the ADAPTIVE instruction is counting down until its next specialization attempt.
This only happens after a specialization failure.

Look at the numbers. deferred ≈ sum(specialization-failures) * ADAPTIVE_CACHE_BACKOFF

}
fail:
STAT_INC(BINARY_MULTIPLY, specialization_failure);
assert(!PyErr_Occurred());
*instr = _Py_MAKECODEUNIT(_Py_OPCODE(*instr), ADAPTIVE_CACHE_BACKOFF);
return 0;
success:
STAT_INC(BINARY_MULTIPLY, specialization_success);
assert(!PyErr_Occurred());
return 0;
}