GCC

https://www.airs.com/dnovillo/Papers/eci2008.pdf Use -fverbose-asm -save-temps to determine what flags were enabled by -Ox Use -fno-... to disable a specific pass

http://www.cs.utexas.edu/users/mckinley/380C/lecs/lectures.html https://engineering.purdue.edu/~milind/ece663/2010spring/ https://www.inf.ed.ac.uk/teaching/courses/ct/17-18/ https://bitbucket.org/cdubach/ct-17-18/ [DU chain] https://courses.cs.cornell.edu/cs412/2004sp/lectures/lec36.pdf

CPPFLAGS=-g -pthread -Q -v You can run gcc -Q -v on a small C file to have GCC dump the options being used. Run it with and without the -O1 option to get the difference between the enabled options.

https://stackoverflow.com/questions/2219829/how-to-prevent-gcc-optimizing-some-statements-in-c #pragma GCC push_options #pragma GCC optimize ( "O0" ) your code #pragma GCC pop_options