On 11/12/2009 05:19 PM, Mark Mitchell wrote:
So, I still tend to think that the best thing is to put the vector stuff into v4, and switch that on when we update libstdc++. I think your suggest is coherent and well-reasoned, but it seems like a lot of complexity to deal with a template corner case.
It isn't such a corner case, unfortunately; any code that tries to overload on multiple vector sizes (i.e. MMX and SSE vectors) will break. See bug 12909 and its duplicates. This is becoming more of a problem with the advent of the Intel AVX extension.
I guess another option is -fabi-version=implement-c++-for-petes-sake which means "use the ABI that implements as much of the language as possible". That would be your version 2.1, but arguably more logically coherent in that it would be expected to move in the future if/when we find another feature we can't implement due to current mangling issues.
That seems useful, but I would also want a way to specify a particular revision.
Jason