bpo-24340: Fix estimation of the code stack size. by serhiy-storchaka · Pull Request #5076 · python/cpython

new_depth = depth + PyCompile_OpcodeStackEffectEx(opcode, oparg, 0);
if (new_depth > maxdepth)
    maxdepth = new_depth;
if (isjump) {
    target_depth = depth + PyCompile_OpcodeStackEffectEx(opcode, oparg, 1);
    maxdepth = stackdepth_walk(c, instr->i_target, target_depth, maxdepth);
}
depth = new_depth;