GCC 4.6 and 4.7 had regressed with GraphicsMagick when setting the first-generation Bulldozer optimizations while the Open64 performance was not affected. However, when enabling the highest optimization level with bdver1, the regression was erased. In some cases, these maxed-out binaries were much faster.
The Bulldozer optimizations also caused the GCC-built binaries to regress for the Gcrypt benchmark while under Open64 they were running at the same speed. Setting "-Ofast" for Gcrypt caused broken binaries.
Next up are benchmarks from Open64 5.0 on Bulldozer.