msinttypes
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chemeris
fast types should match native word size
I think "fast" types are supposed to allow fast operations (basically,
efficiently use the registers) on the target machines.
Example: int_fast16_t is currently defined as 16-bit integer, which is slow
on modern machines. It should definitely map to the same type as
int_fast32_t.
My gut feeling is that even int_fast32_t should map to a 64-bit integer on a
64-bit platform (gcc/glibc do that, for example), but Visual Studio 10
headers define that as "int" (which, if I recall correctly, is 32-bit long on
Windows).
Original issue reported on code.google.com by [email protected] on 11 Mar 2010 at 6:43
I do not know for IA64, but for AMD64 (x64), due to the way the CPU is
organized, 32-bit arithmetic is never slower than 64-bit (they are the same
instructions internally, and the 64-bit one are extensions thus requiring more
decoding, not less.)
On the other hand, 32-bit integers would use less memory and need less code
space for "REX.W" prefixes or for negative constants, so the overall cache
efficiency would be likely better.
Original comment by [email protected] on 31 Dec 2014 at 4:56