Only eliminate jumps to successor block if jump is unconditional. (GH-24417)
* Prevents elimination of the sole test of a value in statements like:
if x or True: ...
diff --git a/Python/compile.c b/Python/compile.c
index 9927f5a..a0a257f 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -6586,27 +6586,14 @@ optimize_cfg(struct assembler *a, PyObject *consts)
for (basicblock *b = a->a_entry; b != NULL; b = b->b_next) {
if (b->b_iused > 0) {
struct instr *b_last_instr = &b->b_instr[b->b_iused - 1];
- if (b_last_instr->i_opcode == POP_JUMP_IF_FALSE ||
- b_last_instr->i_opcode == POP_JUMP_IF_TRUE ||
- b_last_instr->i_opcode == JUMP_ABSOLUTE ||
+ if (b_last_instr->i_opcode == JUMP_ABSOLUTE ||
b_last_instr->i_opcode == JUMP_FORWARD) {
if (b_last_instr->i_target == b->b_next) {
assert(b->b_next->b_iused);
b->b_nofallthrough = 0;
- switch(b_last_instr->i_opcode) {
- case POP_JUMP_IF_FALSE:
- case POP_JUMP_IF_TRUE:
- b_last_instr->i_opcode = POP_TOP;
- b_last_instr->i_target = NULL;
- b_last_instr->i_oparg = 0;
- break;
- case JUMP_ABSOLUTE:
- case JUMP_FORWARD:
- b_last_instr->i_opcode = NOP;
- clean_basic_block(b, -1);
- maybe_empty_blocks = 1;
- break;
- }
+ b_last_instr->i_opcode = NOP;
+ clean_basic_block(b, -1);
+ maybe_empty_blocks = 1;
}
}
}