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>some x64 programs did adopt a convention to use shorter pointers, 32-bit pointers on a 64-bit operating system.

It's doable in managed languages, e.g. Java has compressed pointers by default on sub 32GB heaps. I suppose it's doable even in C alike setup (incl OS calls) but that would require wrappers to bit shift the pointers on each dereference (and passive to the OS, extern)

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gpderetta 2 days ago | parent [-]

both GCC and the linux kernel support x32 directly. Distros even shipped system libraries compiled for x32.

There was no uptake and I believe it is deprecated today.

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xxs 2 days ago | parent [-]

With x32 the limit would be 4GB which is on the low side of things. Having 8byte alignment (i.e. last 3 bits zero), allows for 32GB - which is better.

	▲	gpderetta 2 days ago \| parent [-]
		That would work in Java. In C is a bit complicated as you can have pointers with byte granularity. In principle the size of a pointer need not be the same for all types: you can have char, short, int and float pointers be 64 bits and everything else be 32 bits. (void has to be 64 bit as well as you must be able to round trip through it). I suspect that would break 90% of code out there though.