ValueError: no memory after 4GB

Hi,

I'm trying to convert an SVG to a BMP that's about 100,000 pixels by 
100,000 pixels. My code looks like

drawing = svg2rlg( 'infile.svg')
renderPM.drawToFile(drawing, 'outfile.bmp', fmt='BMP')

When I run it I get "ValueError: _renderPM.gstate: no memory."

By attempting this conversion with progressively larger files and 
monitoring the memory usage, I've found that the issue occurs when the 
memory consumption exceeds about 4GB. I've checked that I'm using a 64 
bit version of Python and have been able to create large arrays that 
consume up to 64GB of memory (my total amount of RAM), so it seems like 
the issue is specific to reportlab.

Is this expected? Is there any workaround?

Thank you very much.