[Python-checkins] gh-87092: change assembler to use instruction sequence instead of CFG (#103933)
iritkatriel
webhook-mailer at python.org
Sat Apr 29 07:06:43 EDT 2023
https://github.com/python/cpython/commit/fbf3596c3edadd03b5a8c659e9f27a09e5d1a051
commit: fbf3596c3edadd03b5a8c659e9f27a09e5d1a051
branch: main
author: Irit Katriel <1055913+iritkatriel at users.noreply.github.com>
committer: iritkatriel <1055913+iritkatriel at users.noreply.github.com>
date: 2023-04-29T12:06:04+01:00
summary:
gh-87092: change assembler to use instruction sequence instead of CFG (#103933)
files:
M Include/internal/pycore_compile.h
M Include/internal/pycore_flowgraph.h
M Python/assemble.c
M Python/compile.c
M Python/flowgraph.c
diff --git a/Include/internal/pycore_compile.h b/Include/internal/pycore_compile.h
index f85240c48a89..1a032f652ddd 100644
--- a/Include/internal/pycore_compile.h
+++ b/Include/internal/pycore_compile.h
@@ -19,6 +19,7 @@ PyAPI_FUNC(PyCodeObject*) _PyAST_Compile(
int optimize,
struct _arena *arena);
+static const _PyCompilerSrcLocation NO_LOCATION = {-1, -1, -1, -1};
typedef struct {
int optimize;
@@ -33,15 +34,21 @@ extern int _PyAST_Optimize(
struct _arena *arena,
_PyASTOptimizeState *state);
+typedef struct {
+ int h_offset;
+ int h_startdepth;
+ int h_preserve_lasti;
+} _PyCompile_ExceptHandlerInfo;
typedef struct {
int i_opcode;
int i_oparg;
_PyCompilerSrcLocation i_loc;
-} _PyCompilerInstruction;
+ _PyCompile_ExceptHandlerInfo i_except_handler_info;
+} _PyCompile_Instruction;
typedef struct {
- _PyCompilerInstruction *s_instrs;
+ _PyCompile_Instruction *s_instrs;
int s_allocated;
int s_used;
@@ -82,6 +89,8 @@ int _PyCompile_EnsureArrayLargeEnough(
int _PyCompile_ConstCacheMergeOne(PyObject *const_cache, PyObject **obj);
+int _PyCompile_InstrSize(int opcode, int oparg);
+
/* Access compiler internals for unit testing */
PyAPI_FUNC(PyObject*) _PyCompile_CodeGen(
diff --git a/Include/internal/pycore_flowgraph.h b/Include/internal/pycore_flowgraph.h
index f470dad3aaa4..883334f4b182 100644
--- a/Include/internal/pycore_flowgraph.h
+++ b/Include/internal/pycore_flowgraph.h
@@ -11,7 +11,6 @@ extern "C" {
#include "pycore_opcode_utils.h"
#include "pycore_compile.h"
-static const _PyCompilerSrcLocation NO_LOCATION = {-1, -1, -1, -1};
typedef struct {
int i_opcode;
@@ -97,7 +96,6 @@ int _PyCfg_OptimizeCodeUnit(_PyCfgBuilder *g, PyObject *consts, PyObject *const_
int _PyCfg_Stackdepth(_PyCfgBasicblock *entryblock, int code_flags);
void _PyCfg_ConvertExceptionHandlersToNops(_PyCfgBasicblock *entryblock);
int _PyCfg_ResolveJumps(_PyCfgBuilder *g);
-int _PyCfg_InstrSize(_PyCfgInstruction *instruction);
static inline int
@@ -113,7 +111,7 @@ basicblock_nofallthrough(const _PyCfgBasicblock *b) {
PyCodeObject *
_PyAssemble_MakeCodeObject(_PyCompile_CodeUnitMetadata *u, PyObject *const_cache,
- PyObject *consts, int maxdepth, _PyCfgBasicblock *entryblock,
+ PyObject *consts, int maxdepth, _PyCompile_InstructionSequence *instrs,
int nlocalsplus, int code_flags, PyObject *filename);
#ifdef __cplusplus
diff --git a/Python/assemble.c b/Python/assemble.c
index e5a361b230cf..369dd8dcde9b 100644
--- a/Python/assemble.c
+++ b/Python/assemble.c
@@ -1,10 +1,10 @@
#include <stdbool.h>
#include "Python.h"
-#include "pycore_flowgraph.h"
+#include "pycore_code.h" // write_location_entry_start()
#include "pycore_compile.h"
+#include "pycore_opcode.h" // _PyOpcode_Caches[] and opcode category macros
#include "pycore_pymem.h" // _PyMem_IsPtrFreed()
-#include "pycore_code.h" // write_location_entry_start()
#define DEFAULT_CODE_SIZE 128
@@ -22,8 +22,8 @@
}
typedef _PyCompilerSrcLocation location;
-typedef _PyCfgInstruction cfg_instr;
-typedef _PyCfgBasicblock basicblock;
+typedef _PyCompile_Instruction instruction;
+typedef _PyCompile_InstructionSequence instr_sequence;
static inline bool
same_location(location a, location b)
@@ -117,7 +117,8 @@ assemble_emit_exception_table_item(struct assembler *a, int value, int msb)
#define MAX_SIZE_OF_ENTRY 20
static int
-assemble_emit_exception_table_entry(struct assembler *a, int start, int end, basicblock *handler)
+assemble_emit_exception_table_entry(struct assembler *a, int start, int end,
+ _PyCompile_ExceptHandlerInfo *handler)
{
Py_ssize_t len = PyBytes_GET_SIZE(a->a_except_table);
if (a->a_except_table_off + MAX_SIZE_OF_ENTRY >= len) {
@@ -125,13 +126,13 @@ assemble_emit_exception_table_entry(struct assembler *a, int start, int end, bas
}
int size = end-start;
assert(end > start);
- int target = handler->b_offset;
- int depth = handler->b_startdepth - 1;
- if (handler->b_preserve_lasti) {
+ int target = handler->h_offset;
+ int depth = handler->h_startdepth - 1;
+ if (handler->h_preserve_lasti) {
depth -= 1;
}
assert(depth >= 0);
- int depth_lasti = (depth<<1) | handler->b_preserve_lasti;
+ int depth_lasti = (depth<<1) | handler->h_preserve_lasti;
assemble_emit_exception_table_item(a, start, (1<<7));
assemble_emit_exception_table_item(a, size, 0);
assemble_emit_exception_table_item(a, target, 0);
@@ -140,29 +141,26 @@ assemble_emit_exception_table_entry(struct assembler *a, int start, int end, bas
}
static int
-assemble_exception_table(struct assembler *a, basicblock *entryblock)
+assemble_exception_table(struct assembler *a, instr_sequence *instrs)
{
- basicblock *b;
int ioffset = 0;
- basicblock *handler = NULL;
+ _PyCompile_ExceptHandlerInfo handler;
+ handler.h_offset = -1;
int start = -1;
- for (b = entryblock; b != NULL; b = b->b_next) {
- ioffset = b->b_offset;
- for (int i = 0; i < b->b_iused; i++) {
- cfg_instr *instr = &b->b_instr[i];
- if (instr->i_except != handler) {
- if (handler != NULL) {
- RETURN_IF_ERROR(
- assemble_emit_exception_table_entry(a, start, ioffset, handler));
- }
- start = ioffset;
- handler = instr->i_except;
+ for (int i = 0; i < instrs->s_used; i++) {
+ instruction *instr = &instrs->s_instrs[i];
+ if (instr->i_except_handler_info.h_offset != handler.h_offset) {
+ if (handler.h_offset >= 0) {
+ RETURN_IF_ERROR(
+ assemble_emit_exception_table_entry(a, start, ioffset, &handler));
}
- ioffset += _PyCfg_InstrSize(instr);
+ start = ioffset;
+ handler = instr->i_except_handler_info;
}
+ ioffset += _PyCompile_InstrSize(instr->i_opcode, instr->i_oparg);
}
- if (handler != NULL) {
- RETURN_IF_ERROR(assemble_emit_exception_table_entry(a, start, ioffset, handler));
+ if (handler.h_offset >= 0) {
+ RETURN_IF_ERROR(assemble_emit_exception_table_entry(a, start, ioffset, &handler));
}
return SUCCESS;
}
@@ -316,31 +314,31 @@ assemble_emit_location(struct assembler* a, location loc, int isize)
}
static int
-assemble_location_info(struct assembler *a, basicblock *entryblock, int firstlineno)
+assemble_location_info(struct assembler *a, instr_sequence *instrs,
+ int firstlineno)
{
a->a_lineno = firstlineno;
location loc = NO_LOCATION;
int size = 0;
- for (basicblock *b = entryblock; b != NULL; b = b->b_next) {
- for (int j = 0; j < b->b_iused; j++) {
- if (!same_location(loc, b->b_instr[j].i_loc)) {
+ for (int i = 0; i < instrs->s_used; i++) {
+ instruction *instr = &instrs->s_instrs[i];
+ if (!same_location(loc, instr->i_loc)) {
RETURN_IF_ERROR(assemble_emit_location(a, loc, size));
- loc = b->b_instr[j].i_loc;
+ loc = instr->i_loc;
size = 0;
- }
- size += _PyCfg_InstrSize(&b->b_instr[j]);
}
+ size += _PyCompile_InstrSize(instr->i_opcode, instr->i_oparg);
}
RETURN_IF_ERROR(assemble_emit_location(a, loc, size));
return SUCCESS;
}
static void
-write_instr(_Py_CODEUNIT *codestr, cfg_instr *instruction, int ilen)
+write_instr(_Py_CODEUNIT *codestr, instruction *instr, int ilen)
{
- int opcode = instruction->i_opcode;
+ int opcode = instr->i_opcode;
assert(!IS_PSEUDO_OPCODE(opcode));
- int oparg = instruction->i_oparg;
+ int oparg = instr->i_oparg;
assert(HAS_ARG(opcode) || oparg == 0);
int caches = _PyOpcode_Caches[opcode];
switch (ilen - caches) {
@@ -380,12 +378,12 @@ write_instr(_Py_CODEUNIT *codestr, cfg_instr *instruction, int ilen)
*/
static int
-assemble_emit_instr(struct assembler *a, cfg_instr *i)
+assemble_emit_instr(struct assembler *a, instruction *instr)
{
Py_ssize_t len = PyBytes_GET_SIZE(a->a_bytecode);
_Py_CODEUNIT *code;
- int size = _PyCfg_InstrSize(i);
+ int size = _PyCompile_InstrSize(instr->i_opcode, instr->i_oparg);
if (a->a_offset + size >= len / (int)sizeof(_Py_CODEUNIT)) {
if (len > PY_SSIZE_T_MAX / 2) {
return ERROR;
@@ -394,25 +392,24 @@ assemble_emit_instr(struct assembler *a, cfg_instr *i)
}
code = (_Py_CODEUNIT *)PyBytes_AS_STRING(a->a_bytecode) + a->a_offset;
a->a_offset += size;
- write_instr(code, i, size);
+ write_instr(code, instr, size);
return SUCCESS;
}
static int
-assemble_emit(struct assembler *a, basicblock *entryblock, int first_lineno,
- PyObject *const_cache)
+assemble_emit(struct assembler *a, instr_sequence *instrs,
+ int first_lineno, PyObject *const_cache)
{
RETURN_IF_ERROR(assemble_init(a, first_lineno));
- for (basicblock *b = entryblock; b != NULL; b = b->b_next) {
- for (int j = 0; j < b->b_iused; j++) {
- RETURN_IF_ERROR(assemble_emit_instr(a, &b->b_instr[j]));
- }
+ for (int i = 0; i < instrs->s_used; i++) {
+ instruction *instr = &instrs->s_instrs[i];
+ RETURN_IF_ERROR(assemble_emit_instr(a, instr));
}
- RETURN_IF_ERROR(assemble_location_info(a, entryblock, a->a_lineno));
+ RETURN_IF_ERROR(assemble_location_info(a, instrs, a->a_lineno));
- RETURN_IF_ERROR(assemble_exception_table(a, entryblock));
+ RETURN_IF_ERROR(assemble_exception_table(a, instrs));
RETURN_IF_ERROR(_PyBytes_Resize(&a->a_except_table, a->a_except_table_off));
RETURN_IF_ERROR(_PyCompile_ConstCacheMergeOne(const_cache, &a->a_except_table));
@@ -586,13 +583,13 @@ makecode(_PyCompile_CodeUnitMetadata *umd, struct assembler *a, PyObject *const_
PyCodeObject *
_PyAssemble_MakeCodeObject(_PyCompile_CodeUnitMetadata *umd, PyObject *const_cache,
- PyObject *consts, int maxdepth, basicblock *entryblock,
+ PyObject *consts, int maxdepth, instr_sequence *instrs,
int nlocalsplus, int code_flags, PyObject *filename)
{
PyCodeObject *co = NULL;
struct assembler a;
- int res = assemble_emit(&a, entryblock, umd->u_firstlineno, const_cache);
+ int res = assemble_emit(&a, instrs, umd->u_firstlineno, const_cache);
if (res == SUCCESS) {
co = makecode(umd, &a, const_cache, consts, maxdepth, nlocalsplus,
code_flags, filename);
diff --git a/Python/compile.c b/Python/compile.c
index a0ad3687f586..e8789def8673 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -149,7 +149,18 @@ enum {
COMPILER_SCOPE_COMPREHENSION,
};
-typedef _PyCompilerInstruction instruction;
+
+int
+_PyCompile_InstrSize(int opcode, int oparg)
+{
+ assert(!IS_PSEUDO_OPCODE(opcode));
+ assert(HAS_ARG(opcode) || oparg == 0);
+ int extended_args = (0xFFFFFF < oparg) + (0xFFFF < oparg) + (0xFF < oparg);
+ int caches = _PyOpcode_Caches[opcode];
+ return extended_args + 1 + caches;
+}
+
+typedef _PyCompile_Instruction instruction;
typedef _PyCompile_InstructionSequence instr_sequence;
#define INITIAL_INSTR_SEQUENCE_SIZE 100
@@ -6968,10 +6979,6 @@ optimize_and_assemble_code_unit(struct compiler_unit *u, PyObject *const_cache,
goto error;
}
- if (cfg_to_instr_sequence(&g, &optimized_instrs) < 0) {
- goto error;
- }
-
/** Assembly **/
int nlocalsplus = prepare_localsplus(u, &g, code_flags);
if (nlocalsplus < 0) {
@@ -6990,15 +6997,15 @@ optimize_and_assemble_code_unit(struct compiler_unit *u, PyObject *const_cache,
if (_PyCfg_ResolveJumps(&g) < 0) {
goto error;
}
+
+ /* Can't modify the bytecode after computing jump offsets. */
+
if (cfg_to_instr_sequence(&g, &optimized_instrs) < 0) {
goto error;
}
-
- /* Can't modify the bytecode after computing jump offsets. */
-
co = _PyAssemble_MakeCodeObject(&u->u_metadata, const_cache, consts,
- maxdepth, g.g_entryblock, nlocalsplus,
+ maxdepth, &optimized_instrs, nlocalsplus,
code_flags, filename);
error:
@@ -7039,11 +7046,18 @@ cfg_to_instr_sequence(cfg_builder *g, instr_sequence *seq)
RETURN_IF_ERROR(instr_sequence_use_label(seq, b->b_label.id));
for (int i = 0; i < b->b_iused; i++) {
cfg_instr *instr = &b->b_instr[i];
- int arg = HAS_TARGET(instr->i_opcode) ?
- instr->i_target->b_label.id :
- instr->i_oparg;
RETURN_IF_ERROR(
- instr_sequence_addop(seq, instr->i_opcode, arg, instr->i_loc));
+ instr_sequence_addop(seq, instr->i_opcode, instr->i_oparg, instr->i_loc));
+
+ _PyCompile_ExceptHandlerInfo *hi = &seq->s_instrs[seq->s_used-1].i_except_handler_info;
+ if (instr->i_except != NULL) {
+ hi->h_offset = instr->i_except->b_offset;
+ hi->h_startdepth = instr->i_except->b_startdepth;
+ hi->h_preserve_lasti = instr->i_except->b_preserve_lasti;
+ }
+ else {
+ hi->h_offset = -1;
+ }
}
}
return SUCCESS;
diff --git a/Python/flowgraph.c b/Python/flowgraph.c
index 67cc5c5e88be..6f83a910cab3 100644
--- a/Python/flowgraph.c
+++ b/Python/flowgraph.c
@@ -166,16 +166,10 @@ _PyBasicblock_InsertInstruction(basicblock *block, int pos, cfg_instr *instr) {
return SUCCESS;
}
-int
-_PyCfg_InstrSize(cfg_instr *instruction)
+static int
+instr_size(cfg_instr *instruction)
{
- int opcode = instruction->i_opcode;
- assert(!IS_PSEUDO_OPCODE(opcode));
- int oparg = instruction->i_oparg;
- assert(HAS_ARG(opcode) || oparg == 0);
- int extended_args = (0xFFFFFF < oparg) + (0xFFFF < oparg) + (0xFF < oparg);
- int caches = _PyOpcode_Caches[opcode];
- return extended_args + 1 + caches;
+ return _PyCompile_InstrSize(instruction->i_opcode, instruction->i_oparg);
}
static int
@@ -183,7 +177,7 @@ blocksize(basicblock *b)
{
int size = 0;
for (int i = 0; i < b->b_iused; i++) {
- size += _PyCfg_InstrSize(&b->b_instr[i]);
+ size += instr_size(&b->b_instr[i]);
}
return size;
}
@@ -492,7 +486,7 @@ resolve_jump_offsets(basicblock *entryblock)
bsize = b->b_offset;
for (int i = 0; i < b->b_iused; i++) {
cfg_instr *instr = &b->b_instr[i];
- int isize = _PyCfg_InstrSize(instr);
+ int isize = instr_size(instr);
/* jump offsets are computed relative to
* the instruction pointer after fetching
* the jump instruction.
@@ -508,7 +502,7 @@ resolve_jump_offsets(basicblock *entryblock)
assert(!IS_BACKWARDS_JUMP_OPCODE(instr->i_opcode));
instr->i_oparg -= bsize;
}
- if (_PyCfg_InstrSize(instr) != isize) {
+ if (instr_size(instr) != isize) {
extended_arg_recompile = 1;
}
}
@@ -520,7 +514,7 @@ resolve_jump_offsets(basicblock *entryblock)
with a better solution.
The issue is that in the first loop blocksize() is called
- which calls _PyCfg_InstrSize() which requires i_oparg be set
+ which calls instr_size() which requires i_oparg be set
appropriately. There is a bootstrap problem because
i_oparg is calculated in the second loop above.
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