On 03/04/2013 12:29 PM, Tomas Hajny wrote:
It's questionable whether it should be responsibility of a compiler to provide efficient support for threadvars,
If the target platform does not support threadvars a compiler can't do it at all.
If the target platform only provides library calls, a compiler needs to use them.
If the target platform provides dedicated pointer registers for threadvars a compiler can use them.
In all fpc enabled patforms I examined (X86 Windows, X86 Linux, X64-64 Windows, X86-64 Linux, ARM Linux (32 Bits) the platform provides as well library calls as dedicated threadvar pointer registers. In windows the registers seem to be undocumented but obviously "stable", as a change would break a lot existing C/C++ software.
All C/C++ compilers I examined used the threadvar pointer Registers for speed..
-Michael _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-devel
