7.5 Tracing optimized code

By default, all trace levels other than ‘none’ turn off all compiler optimizations that can affect the sequence of trace events generated by the program, such as inlining. If you are specifically interested in how the compiler’s optimizations affect the trace event sequence, you can specify the option ‘--trace-optimized’, which tells the compiler that it does not have to disable those optimizations. (A small number of low-level optimizations have not yet been enhanced to work properly in the presence of tracing, so the compiler disables these even if ‘--trace-optimized’ is given.)