Hi, I have some questions about installing GCC from source code. I need to install GCC in this way to enable performance optimization available for different system architectures. In particular I would like to add the support of graphite tool for the auto parallelize capabilities of GCC. It requires the libraries PPL and CLooG-PPL. I have installed them from repository. Let me begin with the questions: 1) the options mtune=native and march=native allow to detect the current CPU and then to optimize the code. For instance if the CPU is Intel Corei7 then the specific options like maes for AES or msse4 for SSE4 or mavx for AVX are already enabled by default if the options the mtune=native and march=native are provided? Another instance is for the AMD Bulldozer architecture where the XOP, FMA4, and LWP instruction sets can be enabled by mxop, mfma4, and mlwp options. 2) the options with-arch-32, with-arch-64, with-cpu-32, with-cpu-64, with-tune-32 and with-tune-64 are used to control the default optimization separately for 32-bit and 64-bit modes. I don't understand how can I use them. For instance with a 64 bit system for instance Ubuntu 11.10, what are the best setting? with-arch64 with-cpu-64 and with-tune-64? Any suggestions or questions are welcome. Thank you in advance
