I am trying to use the GCC pragma optimize to set global optimizations in my C code. GCC version is 4.4.3 on Ubuntu. The basic idea is to use function specific optimization levels. #pragma GCC optimize ("O3") I get a compilation error just before my main function in my C code But when I build it, I get compilation error as below - passrecovery.c: In function âmainâ: passrecovery.c:493: internal compiler error: Segmentation fault Please submit a full bug report, with preprocessed source if appropriate. See for instructions. make: *** [all] Error 1 I checked the README.Bugs file, mentioned in the error, but found no clues regarding this. Is `#pragma optimize` supported in 4.4.3 GCC or not? If yes, then what is that I am doing incorrectly in using this pragma to optimize the code. Any other alternative GCC directive for optimizing the code for speed? **EDIT**: I even tried `#pragma GCC push_options` then `#pragma GCC optimize ("O3")` and at end of file `#pragma GCC pop_options`; same error.