cpython/Include/internal/pycore_optimizer.h
Ken Jin 22b0de2755
gh-117139: Convert the evaluation stack to stack refs (#118450)
This PR sets up tagged pointers for CPython.

The general idea is to create a separate struct _PyStackRef for everything on the evaluation stack to store the bits. This forces the C compiler to warn us if we try to cast things or pull things out of the struct directly.

Only for free threading: We tag the low bit if something is deferred - that means we skip incref and decref operations on it. This behavior may change in the future if Mark's plans to defer all objects in the interpreter loop pans out.

This implies a strict stack reference discipline is required. ALL incref and decref operations on stackrefs must use the stackref variants. It is unsafe to untag something then do normal incref/decref ops on it.

The new incref and decref variants are called dup and close. They mimic a "handle" API operating on these stackrefs.

Please read Include/internal/pycore_stackref.h for more information!

---------

Co-authored-by: Mark Shannon <9448417+markshannon@users.noreply.github.com>
2024-06-27 03:10:43 +08:00

280 lines
8.6 KiB
C

#ifndef Py_INTERNAL_OPTIMIZER_H
#define Py_INTERNAL_OPTIMIZER_H
#ifdef __cplusplus
extern "C" {
#endif
#ifndef Py_BUILD_CORE
# error "this header requires Py_BUILD_CORE define"
#endif
#include "pycore_uop_ids.h"
#include <stdbool.h>
typedef struct _PyExecutorLinkListNode {
struct _PyExecutorObject *next;
struct _PyExecutorObject *previous;
} _PyExecutorLinkListNode;
/* Bloom filter with m = 256
* https://en.wikipedia.org/wiki/Bloom_filter */
#define _Py_BLOOM_FILTER_WORDS 8
typedef struct {
uint32_t bits[_Py_BLOOM_FILTER_WORDS];
} _PyBloomFilter;
typedef struct {
uint8_t opcode;
uint8_t oparg;
uint8_t valid;
uint8_t linked;
int index; // Index of ENTER_EXECUTOR (if code isn't NULL, below).
_PyBloomFilter bloom;
_PyExecutorLinkListNode links;
PyCodeObject *code; // Weak (NULL if no corresponding ENTER_EXECUTOR).
} _PyVMData;
/* Depending on the format,
* the 32 bits between the oparg and operand are:
* UOP_FORMAT_TARGET:
* uint32_t target;
* UOP_FORMAT_EXIT
* uint16_t exit_index;
* uint16_t error_target;
* UOP_FORMAT_JUMP
* uint16_t jump_target;
* uint16_t error_target;
*/
typedef struct {
uint16_t opcode:14;
uint16_t format:2;
uint16_t oparg;
union {
uint32_t target;
struct {
union {
uint16_t exit_index;
uint16_t jump_target;
};
uint16_t error_target;
};
};
uint64_t operand; // A cache entry
} _PyUOpInstruction;
typedef struct {
uint32_t target;
_Py_BackoffCounter temperature;
const struct _PyExecutorObject *executor;
} _PyExitData;
typedef struct _PyExecutorObject {
PyObject_VAR_HEAD
const _PyUOpInstruction *trace;
_PyVMData vm_data; /* Used by the VM, but opaque to the optimizer */
uint32_t exit_count;
uint32_t code_size;
size_t jit_size;
void *jit_code;
void *jit_side_entry;
_PyExitData exits[1];
} _PyExecutorObject;
typedef struct _PyOptimizerObject _PyOptimizerObject;
/* Should return > 0 if a new executor is created. O if no executor is produced and < 0 if an error occurred. */
typedef int (*_Py_optimize_func)(
_PyOptimizerObject* self, struct _PyInterpreterFrame *frame,
_Py_CODEUNIT *instr, _PyExecutorObject **exec_ptr,
int curr_stackentries);
struct _PyOptimizerObject {
PyObject_HEAD
_Py_optimize_func optimize;
/* Data needed by the optimizer goes here, but is opaque to the VM */
};
/** Test support **/
typedef struct {
_PyOptimizerObject base;
int64_t count;
} _PyCounterOptimizerObject;
_PyOptimizerObject *_Py_SetOptimizer(PyInterpreterState *interp, _PyOptimizerObject* optimizer);
// Export for '_opcode' shared extension (JIT compiler).
PyAPI_FUNC(_PyExecutorObject*) _Py_GetExecutor(PyCodeObject *code, int offset);
void _Py_ExecutorInit(_PyExecutorObject *, const _PyBloomFilter *);
void _Py_ExecutorDetach(_PyExecutorObject *);
void _Py_BloomFilter_Init(_PyBloomFilter *);
void _Py_BloomFilter_Add(_PyBloomFilter *bloom, void *obj);
PyAPI_FUNC(void) _Py_Executor_DependsOn(_PyExecutorObject *executor, void *obj);
// For testing
// Export for '_testinternalcapi' shared extension.
PyAPI_FUNC(_PyOptimizerObject *) _Py_GetOptimizer(void);
PyAPI_FUNC(int) _Py_SetTier2Optimizer(_PyOptimizerObject* optimizer);
PyAPI_FUNC(PyObject *) _PyOptimizer_NewCounter(void);
PyAPI_FUNC(PyObject *) _PyOptimizer_NewUOpOptimizer(void);
#define _Py_MAX_ALLOWED_BUILTINS_MODIFICATIONS 3
#define _Py_MAX_ALLOWED_GLOBALS_MODIFICATIONS 6
#ifdef _Py_TIER2
PyAPI_FUNC(void) _Py_Executors_InvalidateDependency(PyInterpreterState *interp, void *obj, int is_invalidation);
PyAPI_FUNC(void) _Py_Executors_InvalidateAll(PyInterpreterState *interp, int is_invalidation);
#else
# define _Py_Executors_InvalidateDependency(A, B, C) ((void)0)
# define _Py_Executors_InvalidateAll(A, B) ((void)0)
#endif
// This is the length of the trace we project initially.
#define UOP_MAX_TRACE_LENGTH 800
#define TRACE_STACK_SIZE 5
int _Py_uop_analyze_and_optimize(struct _PyInterpreterFrame *frame,
_PyUOpInstruction *trace, int trace_len, int curr_stackentries,
_PyBloomFilter *dependencies);
extern PyTypeObject _PyCounterExecutor_Type;
extern PyTypeObject _PyCounterOptimizer_Type;
extern PyTypeObject _PyDefaultOptimizer_Type;
extern PyTypeObject _PyUOpExecutor_Type;
extern PyTypeObject _PyUOpOptimizer_Type;
/* Symbols */
/* See explanation in optimizer_symbols.c */
struct _Py_UopsSymbol {
int flags; // 0 bits: Top; 2 or more bits: Bottom
PyTypeObject *typ; // Borrowed reference
PyObject *const_val; // Owned reference (!)
unsigned int type_version; // currently stores type version
};
#define UOP_FORMAT_TARGET 0
#define UOP_FORMAT_EXIT 1
#define UOP_FORMAT_JUMP 2
#define UOP_FORMAT_UNUSED 3
static inline uint32_t uop_get_target(const _PyUOpInstruction *inst)
{
assert(inst->format == UOP_FORMAT_TARGET);
return inst->target;
}
static inline uint16_t uop_get_exit_index(const _PyUOpInstruction *inst)
{
assert(inst->format == UOP_FORMAT_EXIT);
return inst->exit_index;
}
static inline uint16_t uop_get_jump_target(const _PyUOpInstruction *inst)
{
assert(inst->format == UOP_FORMAT_JUMP);
return inst->jump_target;
}
static inline uint16_t uop_get_error_target(const _PyUOpInstruction *inst)
{
assert(inst->format != UOP_FORMAT_TARGET);
return inst->error_target;
}
// Holds locals, stack, locals, stack ... co_consts (in that order)
#define MAX_ABSTRACT_INTERP_SIZE 4096
#define TY_ARENA_SIZE (UOP_MAX_TRACE_LENGTH * 5)
// Need extras for root frame and for overflow frame (see TRACE_STACK_PUSH())
#define MAX_ABSTRACT_FRAME_DEPTH (TRACE_STACK_SIZE + 2)
typedef struct _Py_UopsSymbol _Py_UopsSymbol;
struct _Py_UOpsAbstractFrame {
// Max stacklen
int stack_len;
int locals_len;
_Py_UopsSymbol **stack_pointer;
_Py_UopsSymbol **stack;
_Py_UopsSymbol **locals;
};
typedef struct _Py_UOpsAbstractFrame _Py_UOpsAbstractFrame;
typedef struct ty_arena {
int ty_curr_number;
int ty_max_number;
_Py_UopsSymbol arena[TY_ARENA_SIZE];
} ty_arena;
struct _Py_UOpsContext {
char done;
char out_of_space;
bool contradiction;
// The current "executing" frame.
_Py_UOpsAbstractFrame *frame;
_Py_UOpsAbstractFrame frames[MAX_ABSTRACT_FRAME_DEPTH];
int curr_frame_depth;
// Arena for the symbolic types.
ty_arena t_arena;
_Py_UopsSymbol **n_consumed;
_Py_UopsSymbol **limit;
_Py_UopsSymbol *locals_and_stack[MAX_ABSTRACT_INTERP_SIZE];
};
typedef struct _Py_UOpsContext _Py_UOpsContext;
extern bool _Py_uop_sym_is_null(_Py_UopsSymbol *sym);
extern bool _Py_uop_sym_is_not_null(_Py_UopsSymbol *sym);
extern bool _Py_uop_sym_is_const(_Py_UopsSymbol *sym);
extern PyObject *_Py_uop_sym_get_const(_Py_UopsSymbol *sym);
extern _Py_UopsSymbol *_Py_uop_sym_new_unknown(_Py_UOpsContext *ctx);
extern _Py_UopsSymbol *_Py_uop_sym_new_not_null(_Py_UOpsContext *ctx);
extern _Py_UopsSymbol *_Py_uop_sym_new_type(
_Py_UOpsContext *ctx, PyTypeObject *typ);
extern _Py_UopsSymbol *_Py_uop_sym_new_const(_Py_UOpsContext *ctx, PyObject *const_val);
extern _Py_UopsSymbol *_Py_uop_sym_new_null(_Py_UOpsContext *ctx);
extern bool _Py_uop_sym_has_type(_Py_UopsSymbol *sym);
extern bool _Py_uop_sym_matches_type(_Py_UopsSymbol *sym, PyTypeObject *typ);
extern bool _Py_uop_sym_matches_type_version(_Py_UopsSymbol *sym, unsigned int version);
extern void _Py_uop_sym_set_null(_Py_UOpsContext *ctx, _Py_UopsSymbol *sym);
extern void _Py_uop_sym_set_non_null(_Py_UOpsContext *ctx, _Py_UopsSymbol *sym);
extern void _Py_uop_sym_set_type(_Py_UOpsContext *ctx, _Py_UopsSymbol *sym, PyTypeObject *typ);
extern bool _Py_uop_sym_set_type_version(_Py_UOpsContext *ctx, _Py_UopsSymbol *sym, unsigned int version);
extern void _Py_uop_sym_set_const(_Py_UOpsContext *ctx, _Py_UopsSymbol *sym, PyObject *const_val);
extern bool _Py_uop_sym_is_bottom(_Py_UopsSymbol *sym);
extern int _Py_uop_sym_truthiness(_Py_UopsSymbol *sym);
extern PyTypeObject *_Py_uop_sym_get_type(_Py_UopsSymbol *sym);
extern void _Py_uop_abstractcontext_init(_Py_UOpsContext *ctx);
extern void _Py_uop_abstractcontext_fini(_Py_UOpsContext *ctx);
extern _Py_UOpsAbstractFrame *_Py_uop_frame_new(
_Py_UOpsContext *ctx,
PyCodeObject *co,
int curr_stackentries,
_Py_UopsSymbol **args,
int arg_len);
extern int _Py_uop_frame_pop(_Py_UOpsContext *ctx);
PyAPI_FUNC(PyObject *) _Py_uop_symbols_test(PyObject *self, PyObject *ignored);
PyAPI_FUNC(int) _PyOptimizer_Optimize(struct _PyInterpreterFrame *frame, _Py_CODEUNIT *start, _PyStackRef *stack_pointer, _PyExecutorObject **exec_ptr);
#ifdef __cplusplus
}
#endif
#endif /* !Py_INTERNAL_OPTIMIZER_H */