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Alundra

XBOX ONE still Big Endian ?

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Yeah x86-64 means it's the same architecture as PC's use... which means any weird intrinsics that we have in our PC code (BSF, BSLR, SSE, etc) will work just fine in the console version.
No more having to port SSE code to AltiVec and/or the SPU ISA biggrin.png

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The x86 architecture has been little endian since inception ( afaik ) so it stands to reason that a SoC or device with a x86 architecture will be little endian..PowerPC off which the XBox 360 and the Cell Processor in the PS3 were based is big-endian..

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PowerPC off which the XBox 360 and the Cell Processor in the PS3 were based is big-endian

Technically, PowerPC is bi-endian. This also goes for the majority of ARM chips.

 

Although most vendors keep their PowerPC chips in big-endian mode, the chip can operate as little-endian equally well, and can even switch endianess for individual memory pages.

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The x86 architecture has been little endian since inception ( afaik ) so it stands to reason that a SoC or device with a x86 architecture will be little endian..PowerPC off which the XBox 360 and the Cell Processor in the PS3 were based is big-endian..

 

Yes. In more general terms, the chips that are little endian are almost exclusively those that have a legacy in 8-bit chips, like the x86 familly. The reason for this is that 8-bit chips didn't have to think about endianness as it relates to sequential addresses of data types that spanned more than one byte. When the 8bit intel 8008/8080 led to the 16bit 8086, a programmer porting code from one to the other would still expect the low-byte to be at the low address (hence, little-endian) -- keep in mind that most software at the time was written in assembler, so you couldn't simply recompile the program.

 

Chips that came around in the post-8bit era and didn't have that 8bit legacy are almost exclusively big endian or bi endian. I think in the past there were some silicon efficiencies that made big endian more attractive, but those have surely vanished by now. Neither is really better, they're just different.

Edited by Ravyne

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