One can move complexity back and forth between compiler, runtime and processor implementation to some extent. VLIW works really well in some niches. It's harder

One can move complexity back and forth between compiler, runtime and processor implementation to some extent. VLIW works really well in some niches. It's harder to program than single instructions that execute in sequence, either by hand or by compiler, but it simplifies the scheduling for the hardware. Works better if the bundled instructions have similar latency. The key design puzzle at present seems to be that memory access takes many more cycles than arithmetic. Bundling a few cycles of arithmetic with a few hundred cycles of memory load is kind of pointless. So VLIW works well if you know memory access is going to be fast, which roughly means knowing it'll hit in L1 cache or equivalent. I think that's part of why it suits DSP style systems. Exposed pipelines are an interesting quirk of some of these systems. One instruction in a VLIW bundle writes to a register and subsequent instructions that read from that same register will see the previous value for N subsequent cycles, after which the write becomes visible. They're really confusing to program by hand but compilers can deal with that sort of scheduling.