diff options
Diffstat (limited to 'Python/compile.c')
| -rw-r--r-- | Python/compile.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/Python/compile.c b/Python/compile.c index a7f62bb..1416eb1 100644 --- a/Python/compile.c +++ b/Python/compile.c @@ -128,6 +128,8 @@ typedef struct basicblock_ { unsigned b_nofallthrough : 1; /* Basic block exits scope (it ends with a return or raise) */ unsigned b_exit : 1; + /* Used by compiler passes to mark whether they have visited a basic block. */ + unsigned b_visited : 1; /* depth of stack upon entry of block, computed by stackdepth() */ int b_startdepth; /* instruction offset for block, computed by assemble_jump_offsets() */ @@ -6702,6 +6704,31 @@ assemble_emit(struct assembler *a, struct instr *i) } static void +normalize_jumps(struct assembler *a) +{ + for (basicblock *b = a->a_entry; b != NULL; b = b->b_next) { + b->b_visited = 0; + } + for (basicblock *b = a->a_entry; b != NULL; b = b->b_next) { + b->b_visited = 1; + if (b->b_iused == 0) { + continue; + } + struct instr *last = &b->b_instr[b->b_iused-1]; + if (last->i_opcode == JUMP_ABSOLUTE) { + if (last->i_target->b_visited == 0) { + last->i_opcode = JUMP_FORWARD; + } + } + if (last->i_opcode == JUMP_FORWARD) { + if (last->i_target->b_visited == 1) { + last->i_opcode = JUMP_ABSOLUTE; + } + } + } +} + +static void assemble_jump_offsets(struct assembler *a, struct compiler *c) { basicblock *b; @@ -7137,6 +7164,10 @@ assemble(struct compiler *c, int addNone) } propagate_line_numbers(&a); guarantee_lineno_for_exits(&a, c->u->u_firstlineno); + + /* Order of basic blocks must have been determined by now */ + normalize_jumps(&a); + /* Can't modify the bytecode after computing jump offsets. */ assemble_jump_offsets(&a, c); |