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by saagarjha 2249 days ago
> CHAR_BIT needs to be 8.

Why?

1 comments

Everything breaks if it isn't.

I was on an OS development team in the 1990s. We were using the SHARC DSP, which was naturally a word-addressed chip. Endianness didn't exist in hardware, since everything was whatever size (32, 40, or 48 bits) you had on the other end of the bus. Adding 1 to a hardware pointer would move by 1 bus width. The chip vendor thought that CHAR_BIT could be 32 and sizeof(long) could be 1.

We couldn't ship it that way. Customers wanted to run real-world source code and they wanted to employ normal software developers. We hacked up the compiler to rotate data addresses by 2 bits so that we could make CHAR_BIT equal to 8.

That was the 1990s, with an audience of embedded RTOS developers who were willing to put up with almost anything for performance. People are even less forgiving today. If strangely sized char couldn't be a viable product back in the 1990s, it has no chance today. It's dead. CHAR_BIT is 8 and will forever be so.

This was a really interesting and enlightening comment and a small story! Thank you!