Messages in this thread | | | Date | Tue, 9 Mar 1999 12:22:10 +0100 (MET) | From | Gabriel Paubert <> | Subject | Re: Linux/IA-64 byte order |
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On 9 Mar 1999, H. Peter Anvin wrote:
> BOGON ALERT! This is a human presentation, i.e. an I/O, issue. > Personally I consider that once you start digging, littleendian is > actually a superior format, making casting of integer pointers for the > most part a noop, and generally having a multiplier that is dependent > only on position. For bigendian to make sense, integer pointers > should point to the *end* of an integer (humans want their numbers > right-adjusted too!), not the beginning.
I agree that it is an I/O issue but I always consider that big endian is superior (and for little endian to make sense, strings should be stored backwards). The ultimate idiocy[1] is standard scientific notation with exponent on one side and most significant digit on the other. As an astronomer, I often disregard all the intermediate digits, the only interesting part are the exponent[2] and (marginally) the first digit (to help rounding up or down the exponent). And I definitely don't want my numbers right adjusted, that may be ok for beancounters, not for scientists (actually I find reading IEEE floating point values in hex on BE machines much more logical).
BTW: casting of integer pointers in C is a nop AFAICT, simply the size of the data accessed by the pointer is changed.
> I see bigendianism as a very unfortunate historical accident, probably > caused by the importation of a number system from a region with a > right-to-left script into another region with a left-to-right script > many hundreds of years ago.
'Arabic' numbers were actually imported from India and a left-to-right original script IIRC. Anyway let us agree to disagree.
Gabriel.
[1] The other one is the 68000 family of processors when single bit instructions use little endian numbering but bit field instuctions (introduced with the 68020) big endian (IOW a bit field of 1 bit is not a single bit). In a big endian machine, bit 0 is the MSB, period.
[2] "If you hear '10 to the 40 within a factor of 2' in an astronomical congress, you have to understand that the factor of 2 applies to the exponent." (I can't remember the source, sigh...)
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