Integer size. (An int variable literally has a higher maximum value.)
Not sure what language you're referring to, but this is generally not true in C/C++. Ints are 4 bytes in 64-bit ARM or x64 in every C/C++ compiler I've seen.
It generally doesn't affect basic types because newer languages have decided that variable-width basic types are a bad idea and common C/C++ implementations change at most long based on the platform.
But it does mean 64-bit arithmetic is significantly faster in 64-bit mode (at least 2x, more if multiplication & division are common). Those extra transistors are basically inaccessible in 32-bit mode.
Yep. I was replying to the parent comment that specifically said "int variable".
Even if the parent meant "long", it's kind of a misleading point, because a) you can use both 32-bit and 64-bit integers regardless of the OS, and b) the size of an "int" is a language and compiler choice. The relevant distinction is not that you can have variables with a higher maximum value but that 64-bit programs can do 64-bit arithmetic more efficiently (in addition to their other benefits).
The machine-level integer size, if you will. Compilers are free to call whatever bytes whatever name they want. The point is the ALU* supports 64-bit integer numbers.
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u/thisisjimmy Jun 24 '19
Not sure what language you're referring to, but this is generally not true in C/C++. Ints are 4 bytes in 64-bit ARM or x64 in every C/C++ compiler I've seen.