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Hello! Is there a way to tell LLVM how to emulate an instruction with multiple others? Specifically, in our processor, there is no instruction for adding two i64s; it has to be done like this dst_high32:dst_low32 = src1_low32 + src2_low32 (unsigned add; dst_high might contain the overflow bit) dst_high32 = dst_high32 + src1_high32 dst_high32 = dst_high32 + src2_high32 I tried it with patterns like the following in InstrInfo.td (this is obviously wrong, but you have to start somewhere): def :...