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Ask HN: Is big-endian dead?

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Re: Ask HN: Is big-endian dead?

#11

Post by jfries » 

  Little-endian is slightly more confusing for humans
I've heard this before, but the reason is that you view hex data and list numbers left-to-right as if they were letters. They are not.

0x12345678 stored big-endian, numbering bytes left-to-right:

  12 34 56 78
Looks good, but I think that this is actually more confusing, because when you number the bytes and bits you will see that the bytes are written left-to-right, while at the same time the bits are written right-to-left.

The solution is to show dumps with bytes numbered right-to-left. This is coherent with how we number bits, and also how we relatively position digits in any other number.

0x12345678 in little-endian, but written right-to-left:

  12 34 56 78
Now the numbering of the bytes is consistent with the numbering of bits. You can easy see that bits 0-7 of the bits interpreted as a 32-bit word belong in byte 0, while bits 16-23 belong in byte 2.

Re: Ask HN: Is big-endian dead?

#12

Post by drewg123 »

api wrote: post #3
tlb wrote: post #2

I used to use IETF's network order (big-endian) for everything on disk or over the wire, but I switched to little-endian around 2008. If I ever have to port to a big-endian machine I'll deal with it then. I haven't regretted it yet.

Big-endian is the canonical form for storage and the wire because back when the Internet was designed most "pro" machines were big-endian: Sparc, old MIPS, old PPC, DEC Alpha, etc. All these are dead or dying now. It's easy enough to deal with BE files and protocols by just swapping bytes. I'm referring to hardware architectures. Are there still any big-endian chips out there? Does it still make sense to support big-…

Small pedantic correction from a former Alpha kernel hacker: DEC Alpha was Big Endian only for some rare Cray systems. Everything else was Little Endian.

Re: Ask HN: Is big-endian dead?

#13

Post by monocasa »

Eh, haswell added the movbe instructions. And I wouldn't be surprised if someone in the RISCV world added big endian instructions (they're nice for network processing).

And nearly every powerpc I've seen is big endian, FWIW.

Re: Ask HN: Is big-endian dead?

#15

Post by loeg »

jfries wrote: post #11

Little-endian is slightly more confusing for humans I've heard this before, but the reason is that you view hex data and list numbers left-to-right as if they were letters. They are not. 0x12345678 stored big-endian, numbering bytes left-to-right: 12 34 56 78 Looks good, but I think that this is actually more confusing, because when you number the bytes and bits you will see that the bytes are written left-to-right,…

Your scheme to byteswap little endian in hex displays falls over in the face of differing word sizes.

Re: Ask HN: Is big-endian dead?

#18

Post by phs2501 »

jfries wrote: post #11

Little-endian is slightly more confusing for humans I've heard this before, but the reason is that you view hex data and list numbers left-to-right as if they were letters. They are not. 0x12345678 stored big-endian, numbering bytes left-to-right: 12 34 56 78 Looks good, but I think that this is actually more confusing, because when you number the bytes and bits you will see that the bytes are written left-to-right,…

At least in Freescale's PowerPC documentation, it's convention to number the bits left-to-right in big-endian. So the most-significant bit is bit 0, which matches up with the most-significant big-endian byte being 0. See, for a random example, page 1101 of https://www.nxp.com/docs/en/reference-manual/MPC8379ERM.pdf.

Personally I prefer the little-endian representation.

Re: Ask HN: Is big-endian dead?

#19

Post by jfries »

loeg wrote: post #15
jfries wrote: post #11

Little-endian is slightly more confusing for humans I've heard this before, but the reason is that you view hex data and list numbers left-to-right as if they were letters. They are not. 0x12345678 stored big-endian, numbering bytes left-to-right: 12 34 56 78 Looks good, but I think that this is actually more confusing, because when you number the bytes and bits you will see that the bytes are written left-to-right,…

Your scheme to byteswap little endian in hex displays falls over in the face of differing word sizes.

Not at all, you just list the whole dump right-to-left. Then it works out regardless of word size.
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