Safe CFLAGS

This article attempts to summarize 'safe' settings for CPU flags on Gentoo Linux.

Automatic CPU detection
A recommended default choice for CFLAGS or CXXFLAGS is to use. This enables auto-detection of the CPU's architecture. A possible entry might look like:

Finding the CPU
To identify the model of the CPU, take a look inside for the "cpu family" and "model" numbers like so:

Once this information is found match the CPU to one listed on this page in order to find out the suggested "safe" CFLAGS.

Below is a list of CFLAGS which are to be considered "safe" for the given processors. These are the settings that should be used, especially when unsure which CFLAGS the processor needs.

External resources

 * GCC Online Documentation on GNU.org
 * GCC x86 performance hints