I like.

It says everything I have been saying about the determinism of defined EO, the insecurity of undefined EO, and requirement for complicated compilers if they are to detect conflicting side-effects.

Now, rewrite the rules of what "defined EO" means.

Follow the traditional definition right up to the point where you end up with func1() op func2(). Traditionally with defined EO, func1() must be evaluated before func2(), but change that final step and say, because we got this far with defined EO, we are sure that everything we did to this point was done as the programmers wished it.

So, because the programmer got exactly what he asked for to this point, and func1() and func2() are both marked as being parallelisable, we trust his judgement and we'll go ahead and run func1() and func2() in parallel. No analysis...just do it because the programmer, knowing these modified rules, gave us carte blanche to do so.

If he didn't want that to happen, he would not have placed them either side of a non-serialising operator.

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
Lingua non convalesco, consenesco et abolesco.
Rule 1 has a caveat! -- Who broke the cabal?

In reply to Re^50: Why is EO undefined? (More details!) by BrowserUk
in thread Why is the execution order of subexpressions undefined? by BrowserUk

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