Inlining is disabled by -pg instrumentation for gprof

The Intel Compiler for Linux supports the option -pg. This instruments the binary to allow function level profiling using gprof. To do this, it also disables function inlining, which may result in some loss of performance. This consequence of -pg is not documented in version 12.1 of the Intel Compiler for Linux, but will be documented in future versions.
          For performance analysis and profiling of applications without impacting inlining, Intel® VTune™ Amplifier XE may be used.
For more complete information about compiler optimizations, see our Optimization Notice.