malloc for large allocations

[bernardwidynski--- via Gcc-help <gcc-help@xxxxxxxxxxx>]

I have a computer with 128 gigabytes of memory.
However, when I try to malloc memory, it only works if I malloc less than 64 gigabytes.
Is there some parameter I could change that would allow me to malloc more than 64 gigabytes.
Thanks,
Bernard Widynski