the Makefile for libavcodec in the MythTV 0.11 package has "-march=pentium4" and "-march=pentiumpro" hard coded into it. my athlon XP didn't quite enjoy it. Reproducible: Always Steps to Reproduce: 1. build mythtv 2. 3. Actual Results: illegal instruction errors
Only pentiumpro is hardcoded and that gets converted to whatever -march you configured in your make.conf. Mythtv .11 builds and works just fine on my athlon-xp box. If you're seeing - march=pentium4, you have a serious configuration problem, but I cannot comment further because you didn't post your emerge --info screen. Please provide that so your situation can be futher debuged.
you can close the bug report, sorry about that. it seems that i copied a .bash_profile from another box with those CFLAGS settings in it. very sorry to waste your time.
Right-o! thanks for confirming.