[gambit-list] on macos: clang over gcc

Marc Feeley feeley at iro.umontreal.ca
Wed Sep 20 10:37:18 EDT 2017

By default the configure script searches for gcc before looking for clang.  However… X-code installs “clang” and also “gcc”, and that “gcc” is not the GNU gcc… it is a wrapper around clang/llvm.  So to install the GNU gcc you need to use homebrew like this:

% brew install gcc-7

and then tell the configure script to use that compiler:

% ./configure --enable-single-host CC=gcc-7

You will notice a dramatic decrease in compilation time and in execution time (about 3 or 4 times faster execution if I recall correctly).  On my machine a “make -j8” after a “make clean” takes 30 seconds.


> On Sep 20, 2017, at 3:18 AM, Ben <mailist.ben at srctxt.com> wrote:
> hi
> On macos sierra running the ./configure script gives me the following
> message:
> *** The clang compiler is being used.  Please be aware that the build 
> ***
> *** may take a very long time (over 30 minutes on a fairly fast       
> ***
> *** machine with clang 3.0).  Configuring with GNU GCC will give a    
> ***
> *** faster build (1 min on the same machine with GNU GCC 4.2.1) and   
> ***
> *** the executable will be faster.    
> What can I do to enforce GCC? I cannot see any specific configure
> --options
> Attached you'll find the entire configure log.
> Thanks,
> Ben
> <configure.log>_______________________________________________
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