digraph Memory {
  // IR styles match graph/web/render.js; arrows are use -> definition.
  graph [bgcolor="#fafbfc" fontname="Helvetica" nodesep=0.35 ranksep=0.55 splines=ortho];
  node [fontname="Helvetica" fontsize=12 color="#758191" fontcolor="#152330" shape=box style="rounded,filled" fillcolor="#edf3f7"];
  edge [fontname="Helvetica" fontsize=9 color="#536477" fontcolor="#364352" arrowsize=0.7 penwidth=1.5];

  rankdir=BT;

  M [label="Initial memory" shape=octagon style="filled" fillcolor="#dcecff"];
  X [label="Store x = 42" shape=octagon style="filled" fillcolor="#dcecff"];
  Y [label="Loop: Store y" shape=octagon style="filled" fillcolor="#dcecff"];
  L [label="Load x (42)" shape=box style="rounded,filled" fillcolor="#edf3f7"];
  L -> X -> M [color="#2867b2"]; Y -> M [color="#2867b2"];
  MemMerge -> X [color="#2867b2"]; MemMerge -> Y [color="#2867b2"];
  Return -> MemMerge [color="#2867b2"]; Return -> L;
  { rank=same; MemMerge -> L [style=invis]; }
  Y -> X [style=invis]; // Layout only: keep the stores in code order.
  Return [shape=box style="filled" fillcolor="#fff1c4"];
  MemMerge [shape=octagon style="filled" fillcolor="#dcecff"];
}