gdb and pstack

I am trying to build pstack for x86-64 elf64 executables. I could get reliable
stack information with debuggable executables, but since the frame pointer
isn't saved, I get trash for optimized executables. gdb, on the other hand,
does give reliable stack information. I was wondering if someone could point
me in the right direction as to what I need to do get the reliable stack information
(from what's available in the executable).

  - Thanks,
   - Rao.