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I spent 7 years doing x86-64.....so much for not having.....I understand that providing LD-OP for all the operations would take a lot of op code space. But I suspect that there is a distribution of the utility of LD-OP depending upon which operation is involved. e.g. there are probably more instances where load and integer add combined would be useful than load and floating point divide would be. I suspect that determining the few most useful combinations wouldn't be too difficult.
It is from that episode the cemented me on the value of
[Rbase+Rindex<<scale+Displacement] and the utility of LD-OPs
and LD-OP-STs. Then I took that and made a better RISC ISA.
That RISC ISA did not have LD-OP-STs because of OpCode
encoding reasons not from pipelining reasons.
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