Hi, Could someone give some hints of how to describe a FMAC (float mult and add) insn in machine description, it matches d = b*c+a, which is a four operands float instrution. With a glimp through the array optabs[] in genopinit.c, it seems no OP handler could match FMAC operation? And I found a function gen_add_mult() in loops.c, but it also seems not very helpful. And another my question is, the element of optabs[] are arrays indexed by machine code, for example, add_optab[] indexed by SI, DI, QI, FI machine mode, not by number of operands, it seems it only matches 3 operands add operation,if I want to add a four operands add operation, what should I do?
Qing
