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Re: Adding Leon processor to the SPARC list of processors
Eric Botcazou wrote:
>> CONFIG_FPU_ENABLE Y/N would correspond to --with-float=hard/soft, and
>> I believe setting CONFIG_IU_V8MULDIV to Y/N requires --with-cpu=V8/V7,
>> is that correct? I think it would make sense to build these as multilibs,
>> so the user can experiment to find out performance impacts of
>> the various hardware configurations on generated code.
>> I wonder if it also would be worthwhile to have compiler options
>> for fpu=fast/slow and multiply=fast/slow, so we can schedule
>> appropriately. For the FPU, issue-rate/latency are as follows:
>> GR FPU: 1/4, with FDIV? 16 and FSQRT? 24 cycles,
>> non-pipelined on separate unit
>> GR FPU Lite: 8/8, with FDIVS/FDIVD/FSQRTS/FSQRTD 31/57/46/57 cycles,
>> non-pipelined on same unit
> Let's not make this too complex for a first try, the settings used at AdaCore
> seem a good starting point to me.