diff options
Diffstat (limited to 'Python/compile.c')
| -rw-r--r-- | Python/compile.c | 83 |
1 files changed, 45 insertions, 38 deletions
diff --git a/Python/compile.c b/Python/compile.c index 51ef8fd..fdf2e5b 100644 --- a/Python/compile.c +++ b/Python/compile.c @@ -7061,7 +7061,6 @@ struct assembler { PyObject *a_except_table; /* bytes containing exception table */ basicblock *a_entry; int a_offset; /* offset into bytecode */ - int a_nblocks; /* number of reachable blocks */ int a_except_table_off; /* offset into exception table */ int a_prevlineno; /* lineno of last emitted line in line table */ int a_prev_end_lineno; /* end_lineno of last emitted line in line table */ @@ -7074,6 +7073,20 @@ struct assembler { int a_location_off; /* offset of last written location info frame */ }; +static basicblock** +make_cfg_traversal_stack(basicblock *entry) { + int nblocks = 0; + for (basicblock *b = entry; b != NULL; b = b->b_next) { + b->b_visited = 0; + nblocks++; + } + basicblock **stack = (basicblock **)PyMem_Malloc(sizeof(basicblock *) * nblocks); + if (!stack) { + PyErr_NoMemory(); + } + return stack; +} + Py_LOCAL_INLINE(void) stackdepth_push(basicblock ***sp, basicblock *b, int depth) { @@ -7089,31 +7102,26 @@ stackdepth_push(basicblock ***sp, basicblock *b, int depth) * cycles in the flow graph have no net effect on the stack depth. */ static int -stackdepth(struct compiler *c) +stackdepth(struct compiler *c, basicblock *entry) { - basicblock *b, *entryblock = NULL; - basicblock **stack, **sp; - int nblocks = 0, maxdepth = 0; - for (b = c->u->u_blocks; b != NULL; b = b->b_list) { + for (basicblock *b = entry; b != NULL; b = b->b_next) { b->b_startdepth = INT_MIN; - entryblock = b; - nblocks++; } - assert(entryblock!= NULL); - stack = (basicblock **)PyObject_Malloc(sizeof(basicblock *) * nblocks); + basicblock **stack = make_cfg_traversal_stack(entry); if (!stack) { - PyErr_NoMemory(); return -1; } - sp = stack; + int maxdepth = 0; + basicblock **sp = stack; if (c->u->u_ste->ste_generator || c->u->u_ste->ste_coroutine) { - stackdepth_push(&sp, entryblock, 1); + stackdepth_push(&sp, entry, 1); } else { - stackdepth_push(&sp, entryblock, 0); + stackdepth_push(&sp, entry, 0); } + while (sp != stack) { - b = *--sp; + basicblock *b = *--sp; int depth = b->b_startdepth; assert(depth >= 0); basicblock *next = b->b_next; @@ -7159,7 +7167,7 @@ stackdepth(struct compiler *c) stackdepth_push(&sp, next, depth); } } - PyObject_Free(stack); + PyMem_Free(stack); return maxdepth; } @@ -7264,14 +7272,8 @@ copy_except_stack(ExceptStack *stack) { static int label_exception_targets(basicblock *entry) { - int nblocks = 0; - for (basicblock *b = entry; b != NULL; b = b->b_next) { - b->b_visited = 0; - nblocks++; - } - basicblock **todo_stack = PyMem_Malloc(sizeof(basicblock *)*nblocks); + basicblock **todo_stack = make_cfg_traversal_stack(entry); if (todo_stack == NULL) { - PyErr_NoMemory(); return -1; } ExceptStack *except_stack = make_except_stack(); @@ -8051,7 +8053,7 @@ static int optimize_cfg(struct compiler *c, struct assembler *a, PyObject *consts); static int -trim_unused_consts(struct compiler *c, struct assembler *a, PyObject *consts); +trim_unused_consts(struct assembler *a, PyObject *consts); /* Duplicates exit BBs, so that line numbers can be propagated to them */ static int @@ -8347,7 +8349,6 @@ assemble(struct compiler *c, int addNone) if (!assemble_init(&a, nblocks, c->u->u_firstlineno)) goto error; a.a_entry = entryblock; - a.a_nblocks = nblocks; int numdropped = fix_cell_offsets(c, entryblock, cellfixedoffsets); PyMem_Free(cellfixedoffsets); // At this point we're done with it. @@ -8368,12 +8369,12 @@ assemble(struct compiler *c, int addNone) if (duplicate_exits_without_lineno(c)) { return NULL; } - if (trim_unused_consts(c, &a, consts)) { + if (trim_unused_consts(&a, consts)) { goto error; } propagate_line_numbers(&a); guarantee_lineno_for_exits(&a, c->u->u_firstlineno); - int maxdepth = stackdepth(c); + int maxdepth = stackdepth(c, entryblock); if (maxdepth < 0) { goto error; } @@ -9081,17 +9082,19 @@ normalize_basic_block(basicblock *bb) { static int mark_reachable(struct assembler *a) { - basicblock **stack, **sp; - sp = stack = (basicblock **)PyObject_Malloc(sizeof(basicblock *) * a->a_nblocks); + basicblock **stack = make_cfg_traversal_stack(a->a_entry); if (stack == NULL) { return -1; } + basicblock **sp = stack; a->a_entry->b_predecessors = 1; *sp++ = a->a_entry; while (sp > stack) { basicblock *b = *(--sp); + b->b_visited = 1; if (b->b_next && !b->b_nofallthrough) { - if (b->b_next->b_predecessors == 0) { + if (!b->b_next->b_visited) { + assert(b->b_next->b_predecessors == 0); *sp++ = b->b_next; } b->b_next->b_predecessors++; @@ -9101,14 +9104,15 @@ mark_reachable(struct assembler *a) { struct instr *instr = &b->b_instr[i]; if (is_jump(instr) || is_block_push(instr)) { target = instr->i_target; - if (target->b_predecessors == 0) { + if (!target->b_visited) { + assert(target->b_predecessors == 0 || target == b->b_next); *sp++ = target; } target->b_predecessors++; } } } - PyObject_Free(stack); + PyMem_Free(stack); return 0; } @@ -9128,12 +9132,15 @@ eliminate_empty_basic_blocks(basicblock *entry) { if (b->b_iused == 0) { continue; } - if (is_jump(&b->b_instr[b->b_iused-1])) { - basicblock *target = b->b_instr[b->b_iused-1].i_target; - while (target->b_iused == 0) { - target = target->b_next; + for (int i = 0; i < b->b_iused; i++) { + struct instr *instr = &b->b_instr[i]; + if (is_jump(instr) || is_block_push(instr)) { + basicblock *target = instr->i_target; + while (target->b_iused == 0) { + target = target->b_next; + } + instr->i_target = target; } - b->b_instr[b->b_iused-1].i_target = target; } } } @@ -9253,7 +9260,7 @@ optimize_cfg(struct compiler *c, struct assembler *a, PyObject *consts) // Remove trailing unused constants. static int -trim_unused_consts(struct compiler *c, struct assembler *a, PyObject *consts) +trim_unused_consts(struct assembler *a, PyObject *consts) { assert(PyList_CheckExact(consts)); |