[llvm-commits] [PATCH] Add MSVC multi processor compilation to build system

[Erik Olofsson]

> -----Original Message-----
> From: Óscar Fuentes [mailto:ofv at wanadoo.es]

> Which are those options? If they are used on the future, having /MP active
> by default may create some inconveniences. Changing the default value of
> option(VAR ...) has no effect if VAR already is on CMakeCache.txt.

Most notably incremental builds and creating a precompiled header. See http://msdn.microsoft.com/en-us/library/bb385193(v=VS.100).aspx

Incremental builds are notoriously buggy, so I don't think we would ever want to enable that by default. If we ever want to add support for precompiled headers I do believe that msbuild automatically strips /MP if that option is enabled.

Regards,
Erik