[LLVMdev] [cfe-dev] New libc++ LLVM Subproject

[Howard Hinnant]

On May 11, 2010, at 9:32 PM, David Leimbach wrote:

>  
> libc++:
> 
> 5 seconds
> 
> libstdc++:
> 
> 22 seconds
> 
> (smaller is better)
>  
> Is this libstdc++ with or without rvalue references?
> 
> How about compile times?  Having used Go a bit, I've been quite fond of how short the code, compile, test loop ends up being.

Tonight compile times look worse.  This isn't completely unexpected as the code size of the libc++ sort is larger than the libstdc++ sort.  Here is a matrix of times.  Each time represents seconds and a median of 3 measurements:

                compile time          run time
              ----------------    ----------------
              libstdc++ libc++    libstdc++ libc++

g++-4.2 -O3      0.62    0.96        23       5
clang++ -O3      0.66    0.80        21       5

Since compile times are usually more important with non-opitimzed builds I computed the same table at -O0:

                compile time          run time
              ----------------    ----------------
              libstdc++ libc++    libstdc++ libc++

g++-4.2 -O0      0.48    .76         186      5
clang++ -O0      0.46    .70         261      5

-Howard