GCC 4.9 is gearing up for a release likely in April so I spent part of Sunday morning running some fresh benchmarks of GCC 4.8.2. vs. GCC 4.9.0 20140323 on an Ubuntu 14.04 LTS system running Linux 3.13 x86_64. Both of the GNU Compiler Collections were built from source in the same configuration. The CFLAGS/CXXFLAGS remained the same during the testing.
All of the system details and results from this weekend GCC 4.9 compiler benchmarking can be found on OpenBenchmarking.org via 1403300-PL-GCC49LATE47. Testing happened from a Core i7 4770K "Haswell" system with the latest version of the Phoronix Test Suite.
Overall, there isn't too much to gain out of GCC 4.9 performance wise for the resulting binaries on the Core i7 Haswell platform for our common C/C++ benchmarks.
While there wasn't much change to see over GCC 4.9.2 for these benchmarks on the latest-generation Intel platform with Ubuntu Linux, GCC 4.9 has many new features and improvements. See the rest of the compiler benchmarks.