• Andreas Zwinkau's avatar
    Revert "jumpthreading must not split edges" · 763b7a16
    Andreas Zwinkau authored
    This reverts commit 2dc83299.
    
    The commit made jumpthreading "more conservative", which fixed the
    problem. However, it is not a good solution in general.
    
    We need a bigger rewrite of opt/jumpthreading, so it analyzes then
    modifies the graph instead of on-the-fly changes. This prevents the
    infinite loop, which would e.g. happen with such a cf graph:
    
        \     A         \     A
       __\    |        __\    |
       |  B   |   =>   |  B   |  => ...
       | / \  |        | / \  |
       |    D |        |    E |
       |     \|        |     \|
        \     C         \     D
         \___/           \   /
                          \_C
    
    Breaks opt/jumpthreading5 and opt/jumpthreading5b
    763b7a16