Talk:Safe Cflags/Intel

-msse*, etc.

I removed all these flags from this page (again). While these aren't "unsafe" flags, keeping track of which flags are applicable to what processors on what GCC versions is beyond the scope of this page, which is designed to provide the simplest base compiler flags one should use on CPU "X". I'm not denying a wiki page describing how to use these options safely would be useful, but this is not the place. Please don't re-add them.


 * I put my money where my mouth is - Hardware CFLAGS
 * dirtyepic@gentoo.org 21:33, 29 November 2010 (GMT)

sse for Core 2 Duo

What are the reasons for and against -msse3 or -msse4 for Core 2 Duo?
 * It depends on the processor. Not all Core 2 Duo's support SSE 4 (4.1, 4.2, or just 4).

About the initial Warning

Considering the last post in this thread about -march=native it seems that the output of gcc -c -x c - -o /dev/null -v -march=native = GCC 4.5

As of today, 9-31-11, GCC stable is at version 4.4.5. GCC 4.5.3-r1 is in testing. march=atom was added in GCC 4.5. Using this setting in a stable build will end in: error: bad value (atom) for -march= switch. The 64-bit profile reflects this, the 32-bit profile does not. I used the recommendation that was previously on this page: CFLAGS="-march=prescott -O2 -pipe -fomit-frame-pointer"