GCC 4.7.0 compiler tuning with Intel Ivy Bridge looking at the performance of various compiler flags. Testing for a future article on Phoronix.com. Tested options were march=nocona, march=core2, march=corei7, march=corei7-avx, and march=core-avx-i. The -O3 was also set for the CFLAG/CXXFLAGS for all runs.