Ask HN: Is big-endian dead? • Hacker News Board

Re: Ask HN: Is big-endian dead?

#31

Post by gumby » Fri, Jan 19, 2018, 7:14 PM UTC

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-…

FWIW every one of the machines you cited (“Sparc, old MIPS, old PPC, DEC Alpha, etc”) post dated the formation of the Internet (the arpanet transitioning to TCP); the Internet protocols just followed existing arpanet practice. Which was due to big-endian processors being common, but the dominant networked machine of that era was the PDP-10.

Re: Ask HN: Is big-endian dead?

#32

Post by gumby » Fri, Jan 19, 2018, 7:16 PM UTC

> Little-endian is slightly more confusing for humans...

I think you meant to write “Little-endian is slightly more confusing for humans who use left-to-right languages” as all the R-L languages also put the least significant digit on the right.

Re: Ask HN: Is big-endian dead?

#33

Post by acallan » Fri, Jan 19, 2018, 7:16 PM UTC

monocasa wrote: post #13

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.

Actually, Silverthorne (the first Atom CPU) added MOVBE.

Re: Ask HN: Is big-endian dead?

#34

Post by echlebek » Fri, Jan 19, 2018, 7:19 PM UTC

Maybe in processors, but not in general.

Why? Because you can use lexicographic sorting with big-endian bytes.

Re: Ask HN: Is big-endian dead?

#35

Post by ComputerGuru » Fri, Jan 19, 2018, 7:20 PM UTC

acallan wrote: post #33

monocasa wrote: post #13

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.

Actually, Silverthorne (the first Atom CPU) added MOVBE.

It seems that Atom has become - ironically - a staging ground for new features that make their way much later to the desktop/mobile x86_64 architecture. Here's another: https://neosmart.net/blog/2017/will-amds-ryzen-finally-bring...

Re: Ask HN: Is big-endian dead?

#36

Post by Const-me » Fri, Jan 19, 2018, 7:21 PM UTC

AlexandrB wrote: post #24

deepnotderp wrote: post #21

I think a couple of networking chips still use it.

I remember reading somewhere that BE was chosen for IP partly for routing efficiency. As you go from MSB to LSB in an IP address you narrow in on an increasingly specific network segment. That's probably not true anymore as smaller and smaller blocks of IPv4 addresses have been handed out (e.g. instead of a full class C).

> That's probably not true anymore

Right, and also because modern RAM is essentially a block device. You just can’t access individual bytes anymore. E.g. on a typical modern PC with a dual-channel DDR, the block size is 128 bits = 16 bytes.

Re: Ask HN: Is big-endian dead?

#37

Post by samat » Fri, Jan 19, 2018, 7:27 PM UTC

gumby wrote: post #32

> Little-endian is slightly more confusing for humans... I think you meant to write “Little-endian is slightly more confusing for humans who use left-to-right languages ” as all the R-L languages also put the least significant digit on the right.

Not true. In arabic languages you write text R-L, but numbers are L-R.

Re: Ask HN: Is big-endian dead?

#38

Post by [deleted] » Fri, Jan 19, 2018, 7:28 PM UTC

gumby wrote: post #32

> Little-endian is slightly more confusing for humans... I think you meant to write “Little-endian is slightly more confusing for humans who use left-to-right languages ” as all the R-L languages also put the least significant digit on the right.

[deleted]

Re: Ask HN: Is big-endian dead?

#39

Post by ufo » Fri, Jan 19, 2018, 7:30 PM UTC

samat wrote: post #37

gumby wrote: post #32

> Little-endian is slightly more confusing for humans... I think you meant to write “Little-endian is slightly more confusing for humans who use left-to-right languages ” as all the R-L languages also put the least significant digit on the right.

Not true. In arabic languages you write text R-L, but numbers are L-R.

Arabic numbers are L-R if you have a big-endian mindset, but R-L if you switch to a little-endian mindset :)

Re: Ask HN: Is big-endian dead?

#40

Post by IshKebab » Fri, Jan 19, 2018, 7:30 PM UTC

Funny I just asked a question about this on SO when I discovered that CBOR - a very recent protocol - uses network byte order (big endian). A confounding decision given that no machines today use it, and it just add extra byte swapping at both ends.

I can't explain it other than presumable there was some guy on the design committee who was like "but.... Unix... the 70s... network byte order... guys!" or something.