Andrew Pinski wrote:
Actually they will with multi threaded program, since you can have a case where it works and now it is broken because one thread has speed up so much it writes to a variable which had a copy on another thread's stack. So the argument about it being too strong is wrong because timming matters now a days. Instruction scheduling can cause the same issue as it forces a write too early for another thread to act on.
But the behavior of such programs is typically fundamentally non-deterministic. I don't think it is useful to lump in this
kind of change with other functional changes. Remember that the standard has NOTHING to say about instruction speeds and even informally, any program depending on relative speeds of two instruction streams is just TOO far out to consider.
Thanks, Andrew Pinski
