# Intel fortran to gfortran **URL:** \ **Category:** Help\ **Created:** [June 10, 2022, 1:16pm UTC](https://fortran-lang.discourse.group/t/intel-fortran-to-gfortran/3711 "2022-06-10T13:16:20Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![RezaRezaei](https://avatars.discourse-cdn.com/v4/letter/r/6a8cbe/32.png) [@RezaRezaei](https://fortran-lang.discourse.group/u/RezaRezaei)\ **Post date:** [June 10, 2022, 1:16pm UTC](https://fortran-lang.discourse.group/t/intel-fortran-to-gfortran/3711/1 "2022-06-10T13:16:20Z")
Hi, I’m trying to use the _gfortran_ to compile a Makefile. However, the flag options are set for _ifort_ compiler, yet the Makefile could be compiled with _gfortran_. Now I need to configure the flag options to match the _gfortran_. I couldn’t find the equivalents of some _ifort_ options in _gfortran_. Could anyone help me in configuring the flag options? The _ifort_ flag options are: `-fixed` `-check` `-fp-stack-check` `-132` Thank you for any help in advance. Reza, ---
**Author:** ![alozada](https://yyz2.discourse-cdn.com/free1/user_avatar/fortran-lang.discourse.group/alozada/32/298_2.png) [@alozada](https://fortran-lang.discourse.group/u/alozada)\ **Post date:** [June 10, 2022, 2:25pm UTC](https://fortran-lang.discourse.group/t/intel-fortran-to-gfortran/3711/2 "2022-06-10T14:25:13Z")
Hi @RezaRezaei, this link can be useful: > [@Equivalent gfort and ifort compilation](https://fortran-lang.discourse.group/t/equivalent-gfort-and-ifort-compilation/3092): > > I am trying to compile a code using gfortran instead of ifortran. The gfortran code runs much much slower than the ifortran code. It does not even use all threads from my computer. I have 40 cores and 80 threads. ifort uses all of them.I think it has to do with the ifort flag /Qm64 but can’t be sure (using the /Qm32 flag on ifort is slower and does not use all the threads on openmp - not sure why). This is the way that visual studio seems to be compiling my code: Compiling with Intel® Fortran… you could also try _fpm_ to build your program [https://fpm.fortran-lang.org/en/index.html](https://fpm.fortran-lang.org/en/index.html) ---
**Author:** ![RezaRezaei](https://avatars.discourse-cdn.com/v4/letter/r/6a8cbe/32.png) [@RezaRezaei](https://fortran-lang.discourse.group/u/RezaRezaei)\ **Post date:** [June 10, 2022, 2:39pm UTC](https://fortran-lang.discourse.group/t/intel-fortran-to-gfortran/3711/3 "2022-06-10T14:39:02Z")
Thank you for responding. Unfortunately, I couldn’t find the mentioned option in the links. ---
**Author:** ![alozada](https://yyz2.discourse-cdn.com/free1/user_avatar/fortran-lang.discourse.group/alozada/32/298_2.png) [@alozada](https://fortran-lang.discourse.group/u/alozada)\ **Post date:** [June 10, 2022, 2:57pm UTC](https://fortran-lang.discourse.group/t/intel-fortran-to-gfortran/3711/4 "2022-06-10T14:57:47Z")
you could also compare these two lists of compile options [gfortran](https://gcc.gnu.org/onlinedocs/gfortran/Fortran-Dialect-Options.html) [ifort](https://www.intel.com/content/www/us/en/develop/documentation/fortran-compiler-oneapi-dev-guide-and-reference/top/compiler-reference/compiler-options/alphabetical-option-list.html) example: -fixed → Specifies source files are in fixed format. _ifort_ -ffixed-form → Specify the layout used by the source file. _gfortran_ ---
**Author:** ![Sideboard](https://yyz2.discourse-cdn.com/free1/user_avatar/fortran-lang.discourse.group/sideboard/32/779_2.png) [@Sideboard](https://fortran-lang.discourse.group/u/Sideboard)\ **Post date:** [June 10, 2022, 3:04pm UTC](https://fortran-lang.discourse.group/t/intel-fortran-to-gfortran/3711/5 "2022-06-10T15:04:08Z")
Is there a an overview of commonly used options for commonly used compilers somewhere? Might be a worthwhile community project. ---
**Author:** ![RezaRezaei](https://avatars.discourse-cdn.com/v4/letter/r/6a8cbe/32.png) [@RezaRezaei](https://fortran-lang.discourse.group/u/RezaRezaei)\ **Post date:** [June 10, 2022, 3:20pm UTC](https://fortran-lang.discourse.group/t/intel-fortran-to-gfortran/3711/7 "2022-06-10T15:20:12Z")
@Sideboard I couldn’t find such a document. ---
**Author:** ![alozada](https://yyz2.discourse-cdn.com/free1/user_avatar/fortran-lang.discourse.group/alozada/32/298_2.png) [@alozada](https://fortran-lang.discourse.group/u/alozada)\ **Post date:** [June 10, 2022, 3:23pm UTC](https://fortran-lang.discourse.group/t/intel-fortran-to-gfortran/3711/8 "2022-06-10T15:23:17Z")
> [@Sideboard](#): > > Might be a worthwhile community project Maybe, a _quick reference card_ that lists the common options between compilers. 🤔 ---
**Author:** ![cmaapic](https://yyz2.discourse-cdn.com/free1/user_avatar/fortran-lang.discourse.group/cmaapic/32/659_2.png) [@cmaapic](https://fortran-lang.discourse.group/u/cmaapic)\ **Post date:** [June 11, 2022, 6:05am UTC](https://fortran-lang.discourse.group/t/intel-fortran-to-gfortran/3711/9 "2022-06-11T06:05:10Z")
Here is a link that people may find useful. [https://polyhedron.com/?page\_id=175](https://polyhedron.com/?page_id=175) ---
**Author:** ![RezaRezaei](https://avatars.discourse-cdn.com/v4/letter/r/6a8cbe/32.png) [@RezaRezaei](https://fortran-lang.discourse.group/u/RezaRezaei)\ **Post date:** [June 12, 2022, 1:32pm UTC](https://fortran-lang.discourse.group/t/intel-fortran-to-gfortran/3711/10 "2022-06-12T13:32:10Z")
I found a comparative collection of different compilers options here: [https://confluence.ecmwf.int/display/UDOC/Compilers](https://confluence.ecmwf.int/display/UDOC/Compilers) [https://doku.lrz.de/pages/viewpage.action?pageId=43320993](https://doku.lrz.de/pages/viewpage.action?pageId=43320993)