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Re: MKSOFTFLOAT for evbppc
On Sep 20, 2012, at 8:31 PM, Simon Burge wrote:
> Matt Thomas wrote:
>>> (Also, for the port page: does fp emulation via traps work? Or is
>>> MKSOFTFLOAT the only way that can possibly work?)
>> Within the past 4 months or so, I added emulation of the FPU so you can
>> run without MKSOFTFLOAT=yes.
> It looks like we've still got the same FPU emulator from the Walnut
> (405GP) days. Way back when (2001?), softfloat was orders of magnitude
> faster on a Walnut. There's the timings for an awk command issued
> during a kernel build at the time:
> emulate: 113.554u 2778.750s 52:30.75 91.7%
> softfloat: 7.607u 1.447s 0:10.57 85.5%
> This was the only reason we did softfloat at the time.
On a P2020, a build.sh distribution for evbppc took 6.2% less time on a
softfloat userland .vs. hardfloat userland with kernel-emulation.
10h55m32s (soft) vs. 11h38m50s (hard)
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