I just discovered the nice "-Minfo=" flag in pgcc, which outputs all the optimizations that the compiler is making.
IE:
pgcc -c -pg -O3 -Minfo=all -Minline -c -o example.o example.c
run:
55, Memory zero idiom, loop replaced by call to __c_mzero8
91, Memory zero idiom, loop replaced by call to __c_mzero8
pgcc -c -pg -O3 -Minfo=all -Minline -c -o controller.o controller.c
main:
82, second inlined, size=4, file controller.c (113)
84, second inlined, size=4, file controller.c (113)
is there an equivalent compiler flag for GCC?
Yes there is. -fopt-info is what you are looking for.
gcc -O3 -fopt-info example.c -o example
Or equivalently you can do
gcc -O3 -fopt-info-all=all.dat example.c -o example
Will output all the optimization information to file all.dat. You can also be specific about which optimization information you want by specifying -fopt-info-options like so:
-fopt-info-loop # info about all loop optimizations
-fopt-info-vec # info about auto-vectorization
-fopt-info-inline # info about function inlining
-fopt-info-ipa # info about all interprocedural optimizations
You can get more specific if you want by telling gcc to dump information only about loops/inlinings/vectorizations that were optimized or were missed
-fopt-info-inline-optimized # info only about functions that were inlined
-fopt-info-vec-missed # info only about vectorizations that were missed
-fopt-info-loop-note # verbose info about loop optimization
For more details look at the online documentation.