Split spiller and register allocator thanks to SSA form. (Simpler and faster than graph coloring.)
IMHO the fixation on graph colouring really held back the development of compilers. SSA was known in the late 80s but for some reason everyone thought graph colouring was the Right Way To Do It, and it only took until the turn of the century for that sentiment to change.
You can (and people do) do graph coloring on SSA form, just the same as you can do linear scan without SSA. SSA helps graph coloring, in fact, thanks to the discovery that the interference graph of SSA values is chordal and the consequences of that...which was only discovered in 2005.
SSA is more of a control flow representation and is broadly orthogonal to register allocation--you can use graph coloring to allocate registers in SSA and you can do linear scan forms of allocation without SSA.
Split spiller and register allocator thanks to SSA form. (Simpler and faster than graph coloring.)
IMHO the fixation on graph colouring really held back the development of compilers. SSA was known in the late 80s but for some reason everyone thought graph colouring was the Right Way To Do It, and it only took until the turn of the century for that sentiment to change.