Specify compiler options for mex command

I compile C-Mex files with the Windows SDK7.1 compilers. Some C-Mex functions profit from the optimization flags "/GL /fp:fast", some other functions don't.

In e.g. Matlab <= R2011b I've created 2 different mexopts.bat files, one with these flags and the other without. Then

mex -f mexopts_Fast.bat ....

is used for compiling with these flags.

After upgrading to R2015b I find in the docs:

 Do Not Use mex -f optionsfile Syntax
 The mex command -f option to specify a build configuration file
 will be removed in a future release.

How can I control the compiler's optimizations flags without using the -f syntax? I did not find a method to provide them as arguments for the mex command.

Answer 1

[James Tursa]

Maybe try some variant of the following:

filename = your source code file name
compiler_option = '/GL /fp:fast';
mex(filename,['COMPFLAGS="$COMPFLAGS ' compiler_option '"']);

[Jan]

What a pitty that mex.getCompilerConfigurations('c') does not offer a method to add an optimitzation flag dynamically.

Answer 2

[JzHartmut]

See Mathworks help mex You can write in a matlab script line:

mex -g COMPFLAGS='$COMPFLAGS /TP /EHa' ...
  files etc.

The COMPFLAGS variable is enhanced. It is used for the installed compiler. In this case that are options for Microsoft Visual Studio.

[Royi Avital]

Pay attention that for Windows you need to use mex -g COMPFLAGS="$COMPFLAGS /TP /EHa" ....

Namely use " instead of '.

[Cris Luengo]

The comment above is only true for the Windows command prompt. If you call mex from within MATLAB, use the sinlge quotes, also on Windows.

[Yavuzhan Erdem]

Can I add the flag to visual studio sfun project ? I am using rtwbuild function and the system is consisting of many subsystems.

[Hartmut Schorrig]

I think using a Visual Studio Project is not in focus, may be not possible. The mex line calls the compiler itself as internal command line. The options after -g are forwarded to the compiler call. Get your own experience.

I don't know yet whether and where the effective called compiler command can be monitored to check what's exact happen. But that will be helpfully.