DragonFlyBSD

phma@darner:/tmp$ g++ -pg -o proftest proftest.cpp
/usr/libexec/binutils222/elf/ld.bfd: cannot find -lm_p
phma@darner:/tmp$ g++ -p -o proftest proftest.cpp
consider using '-pg' instead of '-p' with gprof(1)
/usr/libexec/binutils222/elf/ld.bfd: cannot find -lm_p

The same command succeeds on Linux. I noticed this when trying to profile a much larger program which is a CMake project; the attached program is a minimal program for getting anything useful out of gprof (or would if the loop count were bigger).