cannot use more than 4Gb of memory

[Aki Helin]

Owl slows down and reports 'cannot allocate more memory' when the heap size reaches 4Gb.

[Aki Helin (aoh)]

Owl uses a 32-bit memory model, so the 4Gb limit is intentional. Owl may later become optionally 64-bit and allow processing in several threads and machines. For now the use is mainly on machines with less than 4Gb of memory, so it makes sense to try to conserve it. Also Owl is probably not the right tool for tasks requiring petabytes of memory for now ;)

[Aki Helin (aoh)]

This now only holds when owl is compiled as a 32-bit binary. Note that programs running on 64-bit systems will use only half the memory if compiled with -m32 as was done in previous versions.