https://github.com/python/cpython/commit/fba3b67af47723c201fe3425cb615932970... commit: fba3b67af47723c201fe3425cb615932970a8f28 branch: main author: Irit Katriel <1055913+iritkatriel@users.noreply.github.com> committer: iritkatriel <1055913+iritkatriel@users.noreply.github.com> date: 2022-08-24T16:58:42+01:00 summary: gh-87092: use basicblock_last_instr consistently in the compiler (GH-96243) files: M Python/compile.c diff --git a/Python/compile.c b/Python/compile.c index e5ac162ccc0..627f86a8ce9 100644 --- a/Python/compile.c +++ b/Python/compile.c @@ -291,7 +291,9 @@ typedef struct basicblock_ { static struct instr * basicblock_last_instr(const basicblock *b) { - if (b->b_iused) { + assert(b->b_iused >= 0); + if (b->b_iused > 0) { + assert(b->b_instr != NULL); return &b->b_instr[b->b_iused - 1]; } return NULL; @@ -7168,10 +7170,8 @@ assemble_free(struct assembler *a) static int blocksize(basicblock *b) { - int i; int size = 0; - - for (i = 0; i < b->b_iused; i++) { + for (int i = 0; i < b->b_iused; i++) { size += instr_size(&b->b_instr[i]); } return size; @@ -7746,10 +7746,10 @@ normalize_jumps(basicblock *entryblock) } for (basicblock *b = entryblock; b != NULL; b = b->b_next) { b->b_visited = 1; - if (b->b_iused == 0) { + struct instr *last = basicblock_last_instr(b); + if (last == NULL) { continue; } - struct instr *last = &b->b_instr[b->b_iused-1]; assert(!IS_ASSEMBLER_OPCODE(last->i_opcode)); if (is_jump(last)) { bool is_forward = last->i_target->b_visited == 0; @@ -7915,8 +7915,8 @@ scan_block_for_local(int target, basicblock *b, bool unsafe_to_start, if (b->b_next && BB_HAS_FALLTHROUGH(b)) { MAYBE_PUSH(b->b_next); } - if (b->b_iused > 0) { - struct instr *last = &b->b_instr[b->b_iused-1]; + struct instr *last = basicblock_last_instr(b); + if (last != NULL) { if (is_jump(last)) { assert(last->i_target != NULL); MAYBE_PUSH(last->i_target); @@ -8405,10 +8405,10 @@ guarantee_lineno_for_exits(basicblock *entryblock, int firstlineno) { int lineno = firstlineno; assert(lineno > 0); for (basicblock *b = entryblock; b != NULL; b = b->b_next) { - if (b->b_iused == 0) { + struct instr *last = basicblock_last_instr(b); + if (last == NULL) { continue; } - struct instr *last = &b->b_instr[b->b_iused-1]; if (last->i_loc.lineno < 0) { if (last->i_opcode == RETURN_VALUE) { for (int i = 0; i < b->b_iused; i++) { @@ -8486,18 +8486,18 @@ remove_redundant_jumps(cfg_builder *g) { */ int removed = 0; for (basicblock *b = g->g_entryblock; b != NULL; b = b->b_next) { - if (b->b_iused > 0) { - struct instr *b_last_instr = &b->b_instr[b->b_iused - 1]; - assert(!IS_ASSEMBLER_OPCODE(b_last_instr->i_opcode)); - if (b_last_instr->i_opcode == JUMP || - b_last_instr->i_opcode == JUMP_NO_INTERRUPT) { - if (b_last_instr->i_target == NULL) { + struct instr *last = basicblock_last_instr(b); + if (last != NULL) { + assert(!IS_ASSEMBLER_OPCODE(last->i_opcode)); + if (last->i_opcode == JUMP || + last->i_opcode == JUMP_NO_INTERRUPT) { + if (last->i_target == NULL) { PyErr_SetString(PyExc_SystemError, "jump with NULL target"); return -1; } - if (b_last_instr->i_target == b->b_next) { + if (last->i_target == b->b_next) { assert(b->b_next->b_iused); - b_last_instr->i_opcode = NOP; + last->i_opcode = NOP; removed++; } } @@ -9215,10 +9215,10 @@ basicblock_has_lineno(const basicblock *bb) { */ static int extend_block(basicblock *bb) { - if (bb->b_iused == 0) { + struct instr *last = basicblock_last_instr(bb); + if (last == NULL) { return 0; } - struct instr *last = &bb->b_instr[bb->b_iused-1]; if (last->i_opcode != JUMP && last->i_opcode != JUMP_FORWARD && last->i_opcode != JUMP_BACKWARD) { @@ -9399,7 +9399,8 @@ eliminate_empty_basic_blocks(cfg_builder *g) { static void propagate_line_numbers(basicblock *entryblock) { for (basicblock *b = entryblock; b != NULL; b = b->b_next) { - if (b->b_iused == 0) { + struct instr *last = basicblock_last_instr(b); + if (last == NULL) { continue; } @@ -9418,8 +9419,8 @@ propagate_line_numbers(basicblock *entryblock) { b->b_next->b_instr[0].i_loc = prev_location; } } - if (is_jump(&b->b_instr[b->b_iused-1])) { - basicblock *target = b->b_instr[b->b_iused-1].i_target; + if (is_jump(last)) { + basicblock *target = last->i_target; if (target->b_predecessors == 1) { if (target->b_instr[0].i_loc.lineno < 0) { target->b_instr[0].i_loc = prev_location; @@ -9576,15 +9577,16 @@ duplicate_exits_without_lineno(cfg_builder *g) */ basicblock *entryblock = g->g_entryblock; for (basicblock *b = entryblock; b != NULL; b = b->b_next) { - if (b->b_iused > 0 && is_jump(&b->b_instr[b->b_iused-1])) { - basicblock *target = b->b_instr[b->b_iused-1].i_target; + struct instr *last = basicblock_last_instr(b); + if (last != NULL && is_jump(last)) { + basicblock *target = last->i_target; if (is_exit_without_lineno(target) && target->b_predecessors > 1) { basicblock *new_target = copy_basicblock(g, target); if (new_target == NULL) { return -1; } - new_target->b_instr[0].i_loc = b->b_instr[b->b_iused-1].i_loc; - b->b_instr[b->b_iused-1].i_target = new_target; + new_target->b_instr[0].i_loc = last->i_loc; + last->i_target = new_target; target->b_predecessors--; new_target->b_predecessors = 1; new_target->b_next = target->b_next; @@ -9603,8 +9605,9 @@ duplicate_exits_without_lineno(cfg_builder *g) for (basicblock *b = entryblock; b != NULL; b = b->b_next) { if (BB_HAS_FALLTHROUGH(b) && b->b_next && b->b_iused > 0) { if (is_exit_without_lineno(b->b_next)) { - assert(b->b_next->b_iused > 0); - b->b_next->b_instr[0].i_loc = b->b_instr[b->b_iused-1].i_loc; + struct instr *last = basicblock_last_instr(b); + assert(last != NULL); + b->b_next->b_instr[0].i_loc = last->i_loc; } } }