Windows 10 UNIVERSAL

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kaikun97
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Re: Windows 10 UNIVERSAL

Post by kaikun97 » Thu Feb 04, 2016 3:18 pm

Ezequiel Gomes wrote:Who are you two? other developers?
I am not a developer, I am just relaying what Exophase, who is a developer, has said in the past
viewtopic.php?f=5&t=2969&p=13783
Exophase wrote:Windows Phone isn't a viable option because of its inability to execute dynamically generated code. That is, unless Microsoft changed this.

Ezequiel Gomes
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Re: Windows 10 UNIVERSAL

Post by Ezequiel Gomes » Thu Feb 04, 2016 3:20 pm

Even with the lack of Good I happen to believe in a JIT optimization

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kaikun97
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Re: Windows 10 UNIVERSAL

Post by kaikun97 » Thu Feb 04, 2016 3:21 pm

Ezequiel Gomes wrote:PPSSPP developers managed to optimize very well the emulator for PCs, and now work in universal App PPSSPP to W10. The same could occur pro DS, since the DS is lighter than the PSP
But Drastic DS was developed especially for ARM devices and it may be possible that PPSSPP doesnt JIT. Also the PSP has a MIPS processor whereas the Nintendo DS has an ARM processor, the two types are completely different and emulation may be different for the two.

Exophase
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Re: Windows 10 UNIVERSAL

Post by Exophase » Thu Feb 04, 2016 7:06 pm

As far as I can find Windows 10 Moble does support executing generated code. But it's really a question of who exactly is using Windows 10 Mobile.

DraStic isn't as optimized for x86 as it is for ARM, so that's another consideration when releasing for a platform that's 100% x86. I'm very slowly starting to hand optimize some functions for SSSE3 (the minimum x86 ISA level on Android) but it'll take a while to really get anywhere and I doubt it'll ever be as efficient.

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JeaneMaggie
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Re: Windows 10 UNIVERSAL

Post by JeaneMaggie » Thu Feb 04, 2016 8:46 pm

kaikun97 wrote:
Ezequiel Gomes wrote:PPSSPP developers managed to optimize very well the emulator for PCs, and now work in universal App PPSSPP to W10. The same could occur pro DS, since the DS is lighter than the PSP
But Drastic DS was developed especially for ARM devices and it may be possible that PPSSPP doesnt JIT. Also the PSP has a MIPS processor whereas the Nintendo DS has an ARM processor, the two types are completely different and emulation may be different for the two.
Actually PPSSPP does need jit in order to emulate at most a fourth of PSP games. However if the phone is powerful enough, it doesn't really matter. As you said, it's a hell lot different for ds. Double the screens, double the trouble.
No. No no no no no no.

Exophase
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Re: Windows 10 UNIVERSAL

Post by Exophase » Thu Feb 04, 2016 9:55 pm

JeaneMaggie wrote:Actually PPSSPP does need jit in order to emulate at most a fourth of PSP games. However if the phone is powerful enough, it doesn't really matter. As you said, it's a hell lot different for ds. Double the screens, double the trouble.
Are you saying that there's phone-class hardware that can emulate a significant number of PSP games at proper speed without using a JIT?

If that's true I find that surprising, unless PSP games commonly greatly underutilized the CPU.

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kaikun97
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Re: Windows 10 UNIVERSAL

Post by kaikun97 » Fri Feb 05, 2016 3:29 am

Exophase wrote:
JeaneMaggie wrote:Actually PPSSPP does need jit in order to emulate at most a fourth of PSP games. However if the phone is powerful enough, it doesn't really matter. As you said, it's a hell lot different for ds. Double the screens, double the trouble.
Are you saying that there's phone-class hardware that can emulate a significant number of PSP games at proper speed without using a JIT?

If that's true I find that surprising, unless PSP games commonly greatly underutilized the CPU.
Even with double screens the processing power needed for the DS should still be lower. It only has a 60-ishMHz cpu compared to the 333mhz the psp has. Also if I rightly recall, Drastic DS is partially a hypervisor on ARM devices because of the similarities of the DS's ARM9 and modern ARMv7 and v8 CPUs on phones or am I wrong? :P

Exophase
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Re: Windows 10 UNIVERSAL

Post by Exophase » Fri Feb 05, 2016 4:25 am

kaikun97 wrote:Even with double screens the processing power needed for the DS should still be lower. It only has a 60-ishMHz cpu compared to the 333mhz the psp has.
DS and PSP emulation are really hard to compare. PPSSPP uses a lot of HLE, which it can do because the PSP's OS/SDK software is installed on the PSP itself and therefore you only have to reliably emulate one set of it. The second processor (media engine) generally wouldn't have to be emulated at all, as opposed to DS where ARM7 is emulated (it only runs Nintendo approved software but the libraries included are game-specific)

This also means that for the most part there isn't much in the way of low level peripheral accesses made by the game code. This is in stark contrast to DS games that have a ton of this and it turns into a lot of overhead. PPSSPP uses hardware acceleration for emulating the GPU (with many options to try to tweak how it works), something that's more straightforward to do with decent performance because there's no concern about having to combine it with the output of separate 2D engines.

Besides all that, few PSP games actually run at 333MHz, 222MHz is more typical.
kaikun97 wrote:Also if I rightly recall, Drastic DS is partially a hypervisor on ARM devices because of the similarities of the DS's ARM9 and modern ARMv7 and v8 CPUs on phones or am I wrong? :P
There's nothing resembling a hypervisor/virtualization in DraStic. That's a common mistaken assumption people have it. It uses a traditional recompiler.

Ezequiel Gomes
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Re: Windows 10 UNIVERSAL

Post by Ezequiel Gomes » Fri Feb 05, 2016 2:10 pm

So the emulation is the Drastic is heavier/difficult than PPSSPP?

Exophase
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Re: Windows 10 UNIVERSAL

Post by Exophase » Fri Feb 05, 2016 3:18 pm

Ezequiel Gomes wrote:So the emulation is the Drastic is heavier/difficult than PPSSPP?
In some ways it is, in some ways it's the opposite.. it's really hard to make that comparison. Very different emulators.

On the Pandora handheld (with very outdated hardware) DraStic probably runs games better on average than PPSSPP. But it wouldn't have a prayer of doing so with hires mode enabled on DraStic.

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