3.i. Properly Setting CFLAGS http://www.gentoo.org/proj/en/base/amd64/technotes/index.xml?part=1&chap=3 says to use -O2 yet: 5.a. Important Errata For Gentoo Installation http://www.gentoo.org/proj/en/base/amd64/technotes/index.xml?part=1&chap=5 says: NEVER use -Os in your CFLAGS on the AMD64 platform Which way is correct? Reproducible: Always Steps to Reproduce: See details. Actual Results: See details. Expected Results: Document should be consistent on optimization flags. N/A
-O2 != -Os