There is free
CodeXL from AMD. It has some advanced profiling stuff for AMD same as VTune has for Intel, but for basic profiling it works fine even on Intel CPU's.
As for using gprof on Linux, there is a tool for more advanced profiling called "
perf". It can measure a not only time spent in functions, but also a lot more CPU specific information like cache misses, mispredicted branches, alignment faults and a lot more. Compared to gprof, you don't need to recompile your application with additional arguments except regular debug info.