Realloc/remap down to 4gb in that case sounds OK to me. > 4gb allocated from a structure which can't do any resizing seems moderately unlikely, but sure, I gues

Realloc/remap down to 4gb in that case sounds OK to me. > 4gb allocated from a structure which can't do any resizing seems moderately unlikely, but sure, I guess free is also correct in that case. Two 64 bit values can be returned in registers on the systemv x64 abi, three get passed as a pointer to stack memory. It's an optimisation but I think it's a valid one. 57 bit address space has been coming any year now for maybe a decade, I'll worry about that when it happens.