Function reaches

src/instruction.cpp:607–620

DFS through inputs of `end` to find `start`. `start` must be positioned before `end`.

// DFS through inputs of `end` to find `start`.
// `start` must be positioned before `end`.
bool reaches(instruction_ref start, instruction_ref end)
{
    if(start == end)
        return true;
    std::unordered_set<instruction_ref> visited;
    return fix<bool>([&](auto self, auto ins) -> bool {
        if(ins == start)
            return true;
        // hit a previously visited instruction
        if(not visited.insert(ins).second)
            return false;
        return std::any_of(ins->inputs().begin(), ins->inputs().end(), self);
    })(end);
}

// `reaches` version that checks if instructions are in the module `m`
// Additional condition that stops if DFS instruction's distance to `end`