at Weitek, we built the 1167 at about the same time as the 80287, we lined up compiler guys such as Green Hills to support our alternative coprocessor ASM (the instruction bus was memory mapped in the 80286 address space IIRC) … several folks would hand code inner loops eg for LINPACK, but already by this time the compiler tech was important to fully use the pipeline … loop unrolling, dead code elimination and so on.