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JIT deepest function firstly #10897

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1 change: 1 addition & 0 deletions ext/opcache/jit/zend_jit.h
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Original file line number Diff line number Diff line change
Expand Up @@ -116,6 +116,7 @@ typedef struct _zend_jit_globals {
zend_long max_recursive_calls; /* max number of recursive inlined call unrolls */
zend_long max_recursive_returns; /* max number of recursive inlined return unrolls */
zend_long max_polymorphic_calls; /* max number of inlined polymorphic calls */
zend_long max_inline_func_length; /* max length of inlined functions in one trace */

zend_sym_node *symbols; /* symbols for disassembler */

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4 changes: 3 additions & 1 deletion ext/opcache/jit/zend_jit_internal.h
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Expand Up @@ -359,6 +359,7 @@ zend_constant* ZEND_FASTCALL zend_jit_check_constant(const zval *key);
_(RECURSION_EXIT, "return from recursive function") \
_(BLACK_LIST, "trace blacklisted") \
_(INNER_LOOP, "inner loop") /* trace it */ \
_(JIT_INLINE_FUNC, "JIT inlined function and skip current trace") /* trace inlined function */ \
_(COMPILED_LOOP, "compiled loop") \
_(TRAMPOLINE, "trampoline call") \
_(BAD_FUNC, "bad function call") \
Expand All @@ -383,8 +384,9 @@ typedef enum _zend_jit_trace_stop {
#define ZEND_JIT_TRACE_STOP_DONE(ret) \
(ret < ZEND_JIT_TRACE_STOP_ERROR)

/* restart to trace an inner loop or inlined function */
#define ZEND_JIT_TRACE_STOP_REPEAT(ret) \
(ret == ZEND_JIT_TRACE_STOP_INNER_LOOP)
(ret == ZEND_JIT_TRACE_STOP_INNER_LOOP || ret == ZEND_JIT_TRACE_STOP_JIT_INLINE_FUNC)

#define ZEND_JIT_TRACE_STOP_MAY_RECOVER(ret) \
(ret <= ZEND_JIT_TRACE_STOP_COMPILER_ERROR)
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4 changes: 2 additions & 2 deletions ext/opcache/jit/zend_jit_trace.c
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Expand Up @@ -7696,7 +7696,7 @@ int ZEND_FASTCALL zend_jit_trace_hot_root(zend_execute_data *execute_data, const
zend_jit_trace_stop_description[stop]);
}
if (!ZEND_JIT_TRACE_STOP_MAY_RECOVER(stop)
|| zend_jit_trace_is_bad_root(orig_opline, stop, offset)) {
|| (stop != ZEND_JIT_TRACE_STOP_JIT_INLINE_FUNC && zend_jit_trace_is_bad_root(orig_opline, stop, offset))) {
if (JIT_G(debug) & ZEND_JIT_DEBUG_TRACE_BLACKLIST) {
fprintf(stderr, "---- TRACE %d blacklisted\n",
trace_num);
Expand Down Expand Up @@ -8039,7 +8039,7 @@ int ZEND_FASTCALL zend_jit_trace_hot_side(zend_execute_data *execute_data, uint3
zend_jit_trace_stop_description[stop]);
}
if (!ZEND_JIT_TRACE_STOP_MAY_RECOVER(stop)
|| zend_jit_trace_exit_is_bad(parent_num, exit_num)) {
|| (stop != ZEND_JIT_TRACE_STOP_JIT_INLINE_FUNC && zend_jit_trace_exit_is_bad(parent_num, exit_num))) {
zend_jit_blacklist_trace_exit(parent_num, exit_num);
if (JIT_G(debug) & ZEND_JIT_DEBUG_TRACE_BLACKLIST) {
fprintf(stderr, "---- EXIT %d/%d blacklisted\n",
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7 changes: 7 additions & 0 deletions ext/opcache/jit/zend_jit_vm_helpers.c
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Expand Up @@ -1062,6 +1062,13 @@ zend_jit_trace_stop ZEND_FASTCALL zend_jit_trace_execute(zend_execute_data *ex,

trace_flags = ZEND_OP_TRACE_INFO(opline, offset)->trace_flags;
if (trace_flags) {
/* if inlined functions are too long, stop current tracing and restart a new one */
if (trace_buffer[idx-1].op == ZEND_JIT_TRACE_ENTER && idx > JIT_G(max_inline_func_length)) {
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This doesn't limit the inlined function length. This limits function inlining to the first trace instructions.

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@wxue1 wxue1 Apr 24, 2023 •
edited
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This doesn't limit the inlined function length. This limits function inlining to the first trace instructions.

Actually, JAVA JIT support inlined function up to a particular size. Here we limit size by separating the long trace by max_inline_func_length.

If we limit the inlined function length, some functions may never be JITTed. So I chose a compromise method

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Your code allows inlining only if it occurs in the first 16 instructions of the trace. It easelly prohibits inlining of the short functions.

---- TRACE 44 start (side trace 43/3) WP_Scripts::localize() /home/www/bench/wordpress-3.6/wp-includes/class.wp-scripts.php:148
0027 FE_FREE V8 ; op1(array)
0028 T10 = ROPE_INIT 3 string("var ")
0029 T10 = ROPE_ADD 1 T10 CV1($object_name) ; op2(string)
0030 T9 = ROPE_END 2 T10 string(" = ")
0031 INIT_FCALL 1 96 string("json_encode")
     >init json_encode
0032 SEND_VAR CV2($l10n) 1 ; op1(array)
0033 V10 = DO_ICALL
     >call json_encode
0034 T8 = FAST_CONCAT T9 V10 ; op1(string) op2(string)
0035 CV6($script) = FAST_CONCAT T8 string(";") ; op1(string)
0036 T8 = ISSET_ISEMPTY_CV (empty) CV3($after) ; op1(undef)
0037 ;JMPNZ T8 0042
0042 INIT_METHOD_CALL 2 THIS string("get_data")
     >init WP_Dependencies::get_data
0043 SEND_VAR_EX CV0($handle) 1 ; op1(string)
0044 SEND_VAL_EX string("data") 2
0045 V8 = DO_FCALL
     >enter WP_Dependencies::get_data
---- TRACE 44 abort (JIT inlined function and skip current trace)
---- TRACE 44 start (enter) WP_Dependencies::get_data() /home/www/bench/wordpress-3.6/wp-includes/class.wp-dependencies.php:163
0002 T3 = FETCH_OBJ_IS THIS string("registered") ; val(array)
0003 T2 = ISSET_ISEMPTY_DIM_OBJ (isset) T3 CV0($handle) ; op1(array) op2(string) val(object)
0004 ;JMPNZ T2 0006
0006 T3 = FETCH_OBJ_IS THIS string("registered") ; val(array)
0007 T2 = FETCH_DIM_IS T3 CV0($handle) ; op1(array) op2(string) val(object)
0008 T3 = FETCH_OBJ_IS T2 string("extra") ; op1(object of class _WP_Dependency) val(array)
0009 T2 = ISSET_ISEMPTY_DIM_OBJ (isset) T3 CV1($key) ; op1(array) op2(string) val(undef)
0010 ;JMPNZ T2 0012
0011 RETURN bool(false)
---- TRACE 44 stop (return)

JAVA doesn't use tracing JIT. The current PHP tracing rules were mainly developed on top of LuaJIT.

if (!(trace_flags & ZEND_JIT_TRACE_JITED)) {
stop = ZEND_JIT_TRACE_STOP_JIT_INLINE_FUNC;
break;
}
}
if (trace_flags & ZEND_JIT_TRACE_JITED) {
if (trace_flags & ZEND_JIT_TRACE_START_LOOP) {
if ((start & ZEND_JIT_TRACE_START_LOOP) != 0
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2 changes: 2 additions & 0 deletions ext/opcache/zend_accelerator_module.c
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Expand Up @@ -326,6 +326,7 @@ ZEND_INI_BEGIN()
STD_PHP_INI_ENTRY("opcache.jit_max_root_traces" , "1024", PHP_INI_SYSTEM, OnUpdateLong, max_root_traces, zend_jit_globals, jit_globals)
STD_PHP_INI_ENTRY("opcache.jit_max_side_traces" , "128", PHP_INI_SYSTEM, OnUpdateLong, max_side_traces, zend_jit_globals, jit_globals)
STD_PHP_INI_ENTRY("opcache.jit_max_exit_counters" , "8192", PHP_INI_SYSTEM, OnUpdateLong, max_exit_counters, zend_jit_globals, jit_globals)
STD_PHP_INI_ENTRY("opcache.jit_max_inline_func_length" , "16", PHP_INI_SYSTEM, OnUpdateLong, max_inline_func_length,zend_jit_globals, jit_globals)
STD_PHP_INI_ENTRY("opcache.jit_hot_loop" , "64", PHP_INI_SYSTEM, OnUpdateCounter, hot_loop, zend_jit_globals, jit_globals)
STD_PHP_INI_ENTRY("opcache.jit_hot_func" , "127", PHP_INI_SYSTEM, OnUpdateCounter, hot_func, zend_jit_globals, jit_globals)
STD_PHP_INI_ENTRY("opcache.jit_hot_return" , "8", PHP_INI_SYSTEM, OnUpdateCounter, hot_return, zend_jit_globals, jit_globals)
Expand Down Expand Up @@ -849,6 +850,7 @@ ZEND_FUNCTION(opcache_get_configuration)
add_assoc_long(&directives, "opcache.jit_max_root_traces", JIT_G(max_root_traces));
add_assoc_long(&directives, "opcache.jit_max_side_traces", JIT_G(max_side_traces));
add_assoc_long(&directives, "opcache.jit_prof_threshold", JIT_G(prof_threshold));
add_assoc_long(&directives, "opcache.jit_max_inline_func_length", JIT_G(max_inline_func_length));
#endif

add_assoc_zval(return_value, "directives", &directives);
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