Some 32bit only apps need these libraries, specifically pcsx2 - see bug #141626. I have modified the ebuild to install both versions.
Created attachment 185001 [details, diff] nvidia-cg-toolkit-2.1.0017_multilib.patch
I think the standard way is to create an app-emulation/emul-linux-x86-* package for such libraries.
Then let this bug be a request for a app-emulation/emul-linux-x86-nvidia-cg-toolkit.
I'd summarise bug #262484 and this one into a app-emulation/emul-linux-x86-gllibs package, to prevent creating too many of them.
(In reply to comment #4) > I'd summarise bug #262484 and this one into a > app-emulation/emul-linux-x86-gllibs package, to prevent creating too many of > them. > There already is an opengl use flag for app-emulation/emul-linux-x86-xlibs which installs mesa. Also, the nvidia-cg-toolkit is a binary only package... I don't think the devs will want to include a binary only package with a package where you can at least get the source for it.
I think that creating a new emul package simply for providing this binary package wouldn't make much sense, on the other hand, handling this from nvidia-cg-toolkit ebuild looks much more easy and reasonable for me (something like is currently being done with www-plugins/adobe-flash for example)
See the pcsx2 overlay [1] (now unmaintained) for an example how the ebuild could look like. Was there any progress or investigation on this issue in the past year? [1] https://github.com/eatnumber1/pcsx2-overlay/tree/master/media-gfx/nvidia-cg-toolkit
cc back amd64 if you need our support
+*nvidia-cg-toolkit-3.1.0013 (15 Nov 2012) + + 15 Nov 2012; Justin Lecher <jlec@gentoo.org> files/80cgc-opt-2, + nvidia-cg-toolkit-2.1.0012.ebuild, -nvidia-cg-toolkit-2.1.0016.ebuild, + nvidia-cg-toolkit-2.1.0017.ebuild, nvidia-cg-toolkit-2.1.0017-r1.ebuild, + +nvidia-cg-toolkit-3.1.0013.ebuild: + Version BUmp, #270480, thanks Myckel Habets, Piotr Szymaniak and Jean-Marc + Hengen working on the ebuild; add multilib support, #262477, thanks Russell + Harmon and Dennis Schridde working on this; Add additional variables to + enviroment to find headers and libs, #344603 +