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author | Mark Shannon <mark@hotpy.org> | 2023-05-12 11:21:20 (GMT) |
---|---|---|
committer | GitHub <noreply@github.com> | 2023-05-12 11:21:20 (GMT) |
commit | 45f5aa8fc73acf516071d52ef8213532f0381316 (patch) | |
tree | bc1f7219305185a7befef7003688d7a4359f98e4 /Python | |
parent | 19ee53d52e8adf267dfd588c2142967734a3b65a (diff) | |
download | cpython-45f5aa8fc73acf516071d52ef8213532f0381316.zip cpython-45f5aa8fc73acf516071d52ef8213532f0381316.tar.gz cpython-45f5aa8fc73acf516071d52ef8213532f0381316.tar.bz2 |
GH-103082: Filter LINE events in VM, to simplify tool implementation. (GH-104387)
When monitoring LINE events, instrument all instructions that can have a predecessor on a different line.
Then check that the a new line has been hit in the instrumentation code.
This brings the behavior closer to that of 3.11, simplifying implementation and porting of tools.
Diffstat (limited to 'Python')
-rw-r--r-- | Python/bytecodes.c | 22 | ||||
-rw-r--r-- | Python/ceval.c | 35 | ||||
-rw-r--r-- | Python/ceval_macros.h | 5 | ||||
-rw-r--r-- | Python/generated_cases.c.h | 64 | ||||
-rw-r--r-- | Python/instrumentation.c | 119 | ||||
-rw-r--r-- | Python/legacy_tracing.c | 73 | ||||
-rw-r--r-- | Python/opcode_metadata.h | 5 |
7 files changed, 178 insertions, 145 deletions
diff --git a/Python/bytecodes.c b/Python/bytecodes.c index eee9147..99935a3 100644 --- a/Python/bytecodes.c +++ b/Python/bytecodes.c @@ -3288,28 +3288,6 @@ dummy_func( assert(oparg >= 2); } - inst(INSTRUMENTED_LINE, ( -- )) { - _Py_CODEUNIT *here = next_instr-1; - _PyFrame_SetStackPointer(frame, stack_pointer); - int original_opcode = _Py_call_instrumentation_line( - tstate, frame, here); - stack_pointer = _PyFrame_GetStackPointer(frame); - if (original_opcode < 0) { - next_instr = here+1; - goto error; - } - next_instr = frame->prev_instr; - if (next_instr != here) { - DISPATCH(); - } - if (_PyOpcode_Caches[original_opcode]) { - _PyBinaryOpCache *cache = (_PyBinaryOpCache *)(next_instr+1); - INCREMENT_ADAPTIVE_COUNTER(cache->counter); - } - opcode = original_opcode; - DISPATCH_GOTO(); - } - inst(INSTRUMENTED_INSTRUCTION, ( -- )) { int next_opcode = _Py_call_instrumentation_instruction( tstate, frame, next_instr-1); diff --git a/Python/ceval.c b/Python/ceval.c index 56a3b12..e8534ec 100644 --- a/Python/ceval.c +++ b/Python/ceval.c @@ -775,6 +775,41 @@ handle_eval_breaker: #include "generated_cases.c.h" + /* INSTRUMENTED_LINE has to be here, rather than in bytecodes.c, + * because it needs to capture frame->prev_instr before it is updated, + * as happens in the standard instruction prologue. + */ +#if USE_COMPUTED_GOTOS + TARGET_INSTRUMENTED_LINE: +#else + case INSTRUMENTED_LINE: +#endif + { + _Py_CODEUNIT *prev = frame->prev_instr; + _Py_CODEUNIT *here = frame->prev_instr = next_instr; + _PyFrame_SetStackPointer(frame, stack_pointer); + int original_opcode = _Py_call_instrumentation_line( + tstate, frame, here, prev); + stack_pointer = _PyFrame_GetStackPointer(frame); + if (original_opcode < 0) { + next_instr = here+1; + goto error; + } + next_instr = frame->prev_instr; + if (next_instr != here) { + DISPATCH(); + } + if (_PyOpcode_Caches[original_opcode]) { + _PyBinaryOpCache *cache = (_PyBinaryOpCache *)(next_instr+1); + /* Prevent the underlying instruction from specializing + * and overwriting the instrumentation. */ + INCREMENT_ADAPTIVE_COUNTER(cache->counter); + } + opcode = original_opcode; + DISPATCH_GOTO(); + } + + #if USE_COMPUTED_GOTOS _unknown_opcode: #else diff --git a/Python/ceval_macros.h b/Python/ceval_macros.h index 485771a..f5515d0 100644 --- a/Python/ceval_macros.h +++ b/Python/ceval_macros.h @@ -334,11 +334,10 @@ do { \ #define INSTRUMENTED_JUMP(src, dest, event) \ do { \ _PyFrame_SetStackPointer(frame, stack_pointer); \ - int err = _Py_call_instrumentation_jump(tstate, event, frame, src, dest); \ + next_instr = _Py_call_instrumentation_jump(tstate, event, frame, src, dest); \ stack_pointer = _PyFrame_GetStackPointer(frame); \ - if (err) { \ + if (next_instr == NULL) { \ next_instr = (dest)+1; \ goto error; \ } \ - next_instr = frame->prev_instr; \ } while (0); diff --git a/Python/generated_cases.c.h b/Python/generated_cases.c.h index 2ea15e9..0ded2f9 100644 --- a/Python/generated_cases.c.h +++ b/Python/generated_cases.c.h @@ -4568,32 +4568,8 @@ DISPATCH(); } - TARGET(INSTRUMENTED_LINE) { - #line 3292 "Python/bytecodes.c" - _Py_CODEUNIT *here = next_instr-1; - _PyFrame_SetStackPointer(frame, stack_pointer); - int original_opcode = _Py_call_instrumentation_line( - tstate, frame, here); - stack_pointer = _PyFrame_GetStackPointer(frame); - if (original_opcode < 0) { - next_instr = here+1; - goto error; - } - next_instr = frame->prev_instr; - if (next_instr != here) { - DISPATCH(); - } - if (_PyOpcode_Caches[original_opcode]) { - _PyBinaryOpCache *cache = (_PyBinaryOpCache *)(next_instr+1); - INCREMENT_ADAPTIVE_COUNTER(cache->counter); - } - opcode = original_opcode; - DISPATCH_GOTO(); - #line 4593 "Python/generated_cases.c.h" - } - TARGET(INSTRUMENTED_INSTRUCTION) { - #line 3314 "Python/bytecodes.c" + #line 3292 "Python/bytecodes.c" int next_opcode = _Py_call_instrumentation_instruction( tstate, frame, next_instr-1); if (next_opcode < 0) goto error; @@ -4605,26 +4581,26 @@ assert(next_opcode > 0 && next_opcode < 256); opcode = next_opcode; DISPATCH_GOTO(); - #line 4609 "Python/generated_cases.c.h" + #line 4585 "Python/generated_cases.c.h" } TARGET(INSTRUMENTED_JUMP_FORWARD) { - #line 3328 "Python/bytecodes.c" + #line 3306 "Python/bytecodes.c" INSTRUMENTED_JUMP(next_instr-1, next_instr+oparg, PY_MONITORING_EVENT_JUMP); - #line 4615 "Python/generated_cases.c.h" + #line 4591 "Python/generated_cases.c.h" DISPATCH(); } TARGET(INSTRUMENTED_JUMP_BACKWARD) { - #line 3332 "Python/bytecodes.c" + #line 3310 "Python/bytecodes.c" INSTRUMENTED_JUMP(next_instr-1, next_instr-oparg, PY_MONITORING_EVENT_JUMP); - #line 4622 "Python/generated_cases.c.h" + #line 4598 "Python/generated_cases.c.h" CHECK_EVAL_BREAKER(); DISPATCH(); } TARGET(INSTRUMENTED_POP_JUMP_IF_TRUE) { - #line 3337 "Python/bytecodes.c" + #line 3315 "Python/bytecodes.c" PyObject *cond = POP(); int err = PyObject_IsTrue(cond); Py_DECREF(cond); @@ -4633,12 +4609,12 @@ assert(err == 0 || err == 1); int offset = err*oparg; INSTRUMENTED_JUMP(here, next_instr + offset, PY_MONITORING_EVENT_BRANCH); - #line 4637 "Python/generated_cases.c.h" + #line 4613 "Python/generated_cases.c.h" DISPATCH(); } TARGET(INSTRUMENTED_POP_JUMP_IF_FALSE) { - #line 3348 "Python/bytecodes.c" + #line 3326 "Python/bytecodes.c" PyObject *cond = POP(); int err = PyObject_IsTrue(cond); Py_DECREF(cond); @@ -4647,12 +4623,12 @@ assert(err == 0 || err == 1); int offset = (1-err)*oparg; INSTRUMENTED_JUMP(here, next_instr + offset, PY_MONITORING_EVENT_BRANCH); - #line 4651 "Python/generated_cases.c.h" + #line 4627 "Python/generated_cases.c.h" DISPATCH(); } TARGET(INSTRUMENTED_POP_JUMP_IF_NONE) { - #line 3359 "Python/bytecodes.c" + #line 3337 "Python/bytecodes.c" PyObject *value = POP(); _Py_CODEUNIT *here = next_instr-1; int offset; @@ -4665,12 +4641,12 @@ offset = 0; } INSTRUMENTED_JUMP(here, next_instr + offset, PY_MONITORING_EVENT_BRANCH); - #line 4669 "Python/generated_cases.c.h" + #line 4645 "Python/generated_cases.c.h" DISPATCH(); } TARGET(INSTRUMENTED_POP_JUMP_IF_NOT_NONE) { - #line 3374 "Python/bytecodes.c" + #line 3352 "Python/bytecodes.c" PyObject *value = POP(); _Py_CODEUNIT *here = next_instr-1; int offset; @@ -4683,30 +4659,30 @@ offset = oparg; } INSTRUMENTED_JUMP(here, next_instr + offset, PY_MONITORING_EVENT_BRANCH); - #line 4687 "Python/generated_cases.c.h" + #line 4663 "Python/generated_cases.c.h" DISPATCH(); } TARGET(EXTENDED_ARG) { - #line 3389 "Python/bytecodes.c" + #line 3367 "Python/bytecodes.c" assert(oparg); opcode = next_instr->op.code; oparg = oparg << 8 | next_instr->op.arg; PRE_DISPATCH_GOTO(); DISPATCH_GOTO(); - #line 4698 "Python/generated_cases.c.h" + #line 4674 "Python/generated_cases.c.h" } TARGET(CACHE) { - #line 3397 "Python/bytecodes.c" + #line 3375 "Python/bytecodes.c" assert(0 && "Executing a cache."); Py_UNREACHABLE(); - #line 4705 "Python/generated_cases.c.h" + #line 4681 "Python/generated_cases.c.h" } TARGET(RESERVED) { - #line 3402 "Python/bytecodes.c" + #line 3380 "Python/bytecodes.c" assert(0 && "Executing RESERVED instruction."); Py_UNREACHABLE(); - #line 4712 "Python/generated_cases.c.h" + #line 4688 "Python/generated_cases.c.h" } diff --git a/Python/instrumentation.c b/Python/instrumentation.c index a142324..9152744 100644 --- a/Python/instrumentation.c +++ b/Python/instrumentation.c @@ -14,7 +14,7 @@ /* Uncomment this to dump debugging output when assertions fail */ // #define INSTRUMENT_DEBUG 1 -static PyObject DISABLE = +PyObject _PyInstrumentation_DISABLE = { .ob_refcnt = _Py_IMMORTAL_REFCNT, .ob_type = &PyBaseObject_Type @@ -859,7 +859,7 @@ call_one_instrument( return -1; } Py_DECREF(res); - return (res == &DISABLE); + return (res == &_PyInstrumentation_DISABLE); } static const int8_t MOST_SIGNIFICANT_BITS[16] = { @@ -1002,7 +1002,7 @@ _Py_call_instrumentation_2args( return call_instrumentation_vector(tstate, event, frame, instr, 4, args); } -int +_Py_CODEUNIT * _Py_call_instrumentation_jump( PyThreadState *tstate, int event, _PyInterpreterFrame *frame, _Py_CODEUNIT *instr, _Py_CODEUNIT *target) @@ -1010,17 +1010,27 @@ _Py_call_instrumentation_jump( assert(event == PY_MONITORING_EVENT_JUMP || event == PY_MONITORING_EVENT_BRANCH); assert(frame->prev_instr == instr); + /* Event should occur after the jump */ frame->prev_instr = target; PyCodeObject *code = frame->f_code; int to = (int)(target - _PyCode_CODE(code)); PyObject *to_obj = PyLong_FromLong(to * (int)sizeof(_Py_CODEUNIT)); if (to_obj == NULL) { - return -1; + return NULL; } PyObject *args[4] = { NULL, NULL, NULL, to_obj }; int err = call_instrumentation_vector(tstate, event, frame, instr, 3, args); Py_DECREF(to_obj); - return err; + if (err) { + return NULL; + } + if (frame->prev_instr != target) { + /* The callback has caused a jump (by setting the line number) */ + return frame->prev_instr; + } + /* Reset prev_instr for INSTRUMENTED_LINE */ + frame->prev_instr = instr; + return target; } static void @@ -1076,13 +1086,14 @@ _Py_Instrumentation_GetLine(PyCodeObject *code, int index) } int -_Py_call_instrumentation_line(PyThreadState *tstate, _PyInterpreterFrame* frame, _Py_CODEUNIT *instr) +_Py_call_instrumentation_line(PyThreadState *tstate, _PyInterpreterFrame* frame, _Py_CODEUNIT *instr, _Py_CODEUNIT *prev) { frame->prev_instr = instr; PyCodeObject *code = frame->f_code; assert(is_version_up_to_date(code, tstate->interp)); assert(instrumentation_cross_checks(tstate->interp, code)); int i = (int)(instr - _PyCode_CODE(code)); + _PyCoMonitoringData *monitoring = code->_co_monitoring; _PyCoLineInstrumentationData *line_data = &monitoring->lines[i]; uint8_t original_opcode = line_data->original_opcode; @@ -1092,6 +1103,18 @@ _Py_call_instrumentation_line(PyThreadState *tstate, _PyInterpreterFrame* frame, PyInterpreterState *interp = tstate->interp; int8_t line_delta = line_data->line_delta; int line = compute_line(code, i, line_delta); + assert(line >= 0); + int prev_index = (int)(prev - _PyCode_CODE(code)); + int prev_line = _Py_Instrumentation_GetLine(code, prev_index); + if (prev_line == line) { + int prev_opcode = _PyCode_CODE(code)[prev_index].op.code; + /* RESUME and INSTRUMENTED_RESUME are needed for the operation of + * instrumentation, so must never be hidden by an INSTRUMENTED_LINE. + */ + if (prev_opcode != RESUME && prev_opcode != INSTRUMENTED_RESUME) { + goto done; + } + } uint8_t tools = code->_co_monitoring->line_tools != NULL ? code->_co_monitoring->line_tools[i] : (interp->monitors.tools[PY_MONITORING_EVENT_LINE] | @@ -1275,29 +1298,91 @@ initialize_lines(PyCodeObject *code) line_data[i].original_opcode = 0; break; default: + /* Set original_opcode to the opcode iff the instruction + * starts a line, and thus should be instrumented. + * This saves having to perform this check every time the + * we turn instrumentation on or off, and serves as a sanity + * check when debugging. + */ if (line != current_line && line >= 0) { line_data[i].original_opcode = opcode; } else { line_data[i].original_opcode = 0; } - if (line >= 0) { - current_line = line; - } + current_line = line; } for (int j = 1; j < length; j++) { line_data[i+j].original_opcode = 0; line_data[i+j].line_delta = NO_LINE; } + i += length; + } + for (int i = code->_co_firsttraceable; i < code_len; ) { + int opcode = _Py_GetBaseOpcode(code, i); + int oparg = 0; + while (opcode == EXTENDED_ARG) { + oparg = (oparg << 8) | _PyCode_CODE(code)[i].op.arg; + i++; + opcode = _Py_GetBaseOpcode(code, i); + } + oparg = (oparg << 8) | _PyCode_CODE(code)[i].op.arg; + i += instruction_length(code, i); + int target = -1; switch (opcode) { - case RETURN_VALUE: - case RAISE_VARARGS: - case RERAISE: - /* Blocks of code after these terminators - * should be treated as different lines */ - current_line = -1; + case POP_JUMP_IF_FALSE: + case POP_JUMP_IF_TRUE: + case POP_JUMP_IF_NONE: + case POP_JUMP_IF_NOT_NONE: + case JUMP_FORWARD: + { + target = i + oparg; + break; + } + case FOR_ITER: + case SEND: + { + /* Skip over END_FOR/END_SEND */ + target = i + oparg + 1; + break; + } + case JUMP_BACKWARD: + case JUMP_BACKWARD_NO_INTERRUPT: + { + target = i - oparg; + break; + } + default: + continue; + } + assert(target >= 0); + if (line_data[target].line_delta != NO_LINE) { + line_data[target].original_opcode = _Py_GetBaseOpcode(code, target); + } + } + /* Scan exception table */ + unsigned char *start = (unsigned char *)PyBytes_AS_STRING(code->co_exceptiontable); + unsigned char *end = start + PyBytes_GET_SIZE(code->co_exceptiontable); + unsigned char *scan = start; + while (scan < end) { + int start_offset, size, handler; + scan = parse_varint(scan, &start_offset); + assert(start_offset >= 0 && start_offset < code_len); + scan = parse_varint(scan, &size); + assert(size >= 0 && start_offset+size <= code_len); + scan = parse_varint(scan, &handler); + assert(handler >= 0 && handler < code_len); + int depth_and_lasti; + scan = parse_varint(scan, &depth_and_lasti); + int original_opcode = _Py_GetBaseOpcode(code, handler); + /* Skip if not the start of a line. + * END_ASYNC_FOR is a bit special as it marks the end of + * an `async for` loop, which should not generate its own + * line event. */ + if (line_data[handler].line_delta != NO_LINE && + original_opcode != END_ASYNC_FOR) { + line_data[handler].original_opcode = original_opcode; } - i += length; } } @@ -2010,7 +2095,7 @@ PyObject *_Py_CreateMonitoringObject(void) if (mod == NULL) { return NULL; } - if (PyObject_SetAttrString(mod, "DISABLE", &DISABLE)) { + if (PyObject_SetAttrString(mod, "DISABLE", &_PyInstrumentation_DISABLE)) { goto error; } if (PyObject_SetAttrString(mod, "MISSING", &_PyInstrumentation_MISSING)) { diff --git a/Python/legacy_tracing.c b/Python/legacy_tracing.c index e509e63..5143b79 100644 --- a/Python/legacy_tracing.c +++ b/Python/legacy_tracing.c @@ -4,6 +4,7 @@ #include <stddef.h> #include "Python.h" +#include "opcode.h" #include "pycore_ceval.h" #include "pycore_object.h" #include "pycore_sysmodule.h" @@ -213,7 +214,6 @@ trace_line( if (line < 0) { Py_RETURN_NONE; } - frame ->f_last_traced_line = line; Py_INCREF(frame); frame->f_lineno = line; int err = tstate->c_tracefunc(tstate->c_traceobj, frame, self->event, Py_None); @@ -245,14 +245,12 @@ sys_trace_line_func( return NULL; } assert(args[0] == (PyObject *)frame->f_frame->f_code); - if (frame ->f_last_traced_line == line) { - /* Already traced this line */ - Py_RETURN_NONE; - } return trace_line(tstate, self, frame, line); } - +/* sys.settrace generates line events for all backward + * edges, even if on the same line. + * Handle that case here */ static PyObject * sys_trace_jump_func( _PyLegacyEventHandler *self, PyObject *const *args, @@ -268,61 +266,33 @@ sys_trace_jump_func( assert(from >= 0); int to = _PyLong_AsInt(args[2])/sizeof(_Py_CODEUNIT); assert(to >= 0); - PyFrameObject *frame = PyEval_GetFrame(); - if (frame == NULL) { - PyErr_SetString(PyExc_SystemError, - "Missing frame when calling trace function."); - return NULL; - } - if (!frame->f_trace_lines) { - Py_RETURN_NONE; + if (to > from) { + /* Forward jump */ + return &_PyInstrumentation_DISABLE; } PyCodeObject *code = (PyCodeObject *)args[0]; assert(PyCode_Check(code)); - assert(code == frame->f_frame->f_code); /* We can call _Py_Instrumentation_GetLine because we always set * line events for tracing */ int to_line = _Py_Instrumentation_GetLine(code, to); - /* Backward jump: Always generate event - * Forward jump: Only generate event if jumping to different line. */ - if (to > from && frame->f_last_traced_line == to_line) { - /* Already traced this line */ - Py_RETURN_NONE; + int from_line = _Py_Instrumentation_GetLine(code, from); + if (to_line != from_line) { + /* Will be handled by target INSTRUMENTED_LINE */ + return &_PyInstrumentation_DISABLE; } - return trace_line(tstate, self, frame, to_line); -} - -/* We don't care about the exception here, - * we just treat it as a possible new line - */ -static PyObject * -sys_trace_exception_handled( - _PyLegacyEventHandler *self, PyObject *const *args, - size_t nargsf, PyObject *kwnames -) { - assert(kwnames == NULL); - PyThreadState *tstate = _PyThreadState_GET(); - if (tstate->c_tracefunc == NULL) { - Py_RETURN_NONE; - } - assert(PyVectorcall_NARGS(nargsf) == 3); PyFrameObject *frame = PyEval_GetFrame(); - PyCodeObject *code = (PyCodeObject *)args[0]; - assert(PyCode_Check(code)); + if (frame == NULL) { + PyErr_SetString(PyExc_SystemError, + "Missing frame when calling trace function."); + return NULL; + } assert(code == frame->f_frame->f_code); - assert(PyLong_Check(args[1])); - int offset = _PyLong_AsInt(args[1])/sizeof(_Py_CODEUNIT); - /* We can call _Py_Instrumentation_GetLine because we always set - * line events for tracing */ - int line = _Py_Instrumentation_GetLine(code, offset); - if (frame->f_last_traced_line == line) { - /* Already traced this line */ + if (!frame->f_trace_lines) { Py_RETURN_NONE; } - return trace_line(tstate, self, frame, line); + return trace_line(tstate, self, frame, to_line); } - PyTypeObject _PyLegacyEventHandler_Type = { PyVarObject_HEAD_INIT(&PyType_Type, 0) "sys.legacy_event_handler", @@ -487,7 +457,7 @@ _PyEval_SetTrace(PyThreadState *tstate, Py_tracefunc func, PyObject *arg) } if (set_callbacks(PY_MONITORING_SYS_TRACE_ID, (vectorcallfunc)sys_trace_jump_func, PyTrace_LINE, - PY_MONITORING_EVENT_JUMP, PY_MONITORING_EVENT_BRANCH)) { + PY_MONITORING_EVENT_JUMP, -1)) { return -1; } if (set_callbacks(PY_MONITORING_SYS_TRACE_ID, @@ -495,11 +465,6 @@ _PyEval_SetTrace(PyThreadState *tstate, Py_tracefunc func, PyObject *arg) PY_MONITORING_EVENT_INSTRUCTION, -1)) { return -1; } - if (set_callbacks(PY_MONITORING_SYS_TRACE_ID, - (vectorcallfunc)sys_trace_exception_handled, PyTrace_LINE, - PY_MONITORING_EVENT_EXCEPTION_HANDLED, -1)) { - return -1; - } } int delta = (func != NULL) - (tstate->c_tracefunc != NULL); diff --git a/Python/opcode_metadata.h b/Python/opcode_metadata.h index daf3a38..ae68e04 100644 --- a/Python/opcode_metadata.h +++ b/Python/opcode_metadata.h @@ -367,8 +367,6 @@ _PyOpcode_num_popped(int opcode, int oparg, bool jump) { return 2; case SWAP: return (oparg-2) + 2; - case INSTRUMENTED_LINE: - return 0; case INSTRUMENTED_INSTRUCTION: return 0; case INSTRUMENTED_JUMP_FORWARD: @@ -759,8 +757,6 @@ _PyOpcode_num_pushed(int opcode, int oparg, bool jump) { return 1; case SWAP: return (oparg-2) + 2; - case INSTRUMENTED_LINE: - return 0; case INSTRUMENTED_INSTRUCTION: return 0; case INSTRUMENTED_JUMP_FORWARD: @@ -976,7 +972,6 @@ const struct opcode_metadata _PyOpcode_opcode_metadata[256] = { [COPY] = { true, INSTR_FMT_IB }, [BINARY_OP] = { true, INSTR_FMT_IBC }, [SWAP] = { true, INSTR_FMT_IB }, - [INSTRUMENTED_LINE] = { true, INSTR_FMT_IX }, [INSTRUMENTED_INSTRUCTION] = { true, INSTR_FMT_IX }, [INSTRUMENTED_JUMP_FORWARD] = { true, INSTR_FMT_IB }, [INSTRUMENTED_JUMP_BACKWARD] = { true, INSTR_FMT_IB }, |