> The code, as written, specified a certain set of actions to be taken.

That's a nonsensical statement. "The code, as written" doesn't have any meaning, other than perhaps what you make up in your mind, which is not a useful reference for discussion, unless you also explain what you interpret it to mean.

I understand that maybe you do not actually mean this literally, and that you maybe are just using somewhat imprecise language to get the idea across--the problem is that exactly in the details that you are not spelling out are the problems that this discussion is all about.

> To say that the compiler did not remove any code, or directions to be carried out, when translating to machine code, is to subscribe to a torturous and unuseful definition of the terms we have been using.

No, quite to the contrary. Those definitions might not be useful for day-to-day programming work, but they are exactly the definitions that you need to clearly discuss compiler behaviour, because those are the definitions that the compiler is using, and the compiler is using those definitions because they match the concepts of how you build a compiler.

> Of the actions specified by the programmer in the source file, one of which was optimized out in the translation of that source specification to machine code. This change alters the execution path of the program when it is present

No, there is no "change", that's just confused language. There is a difference between compilation results, but neither of those is in any way the "real" thing, while the other is "changed", they are both equally valid mappings from C to machine code, with one arguably being closer to the intention of the programmer and thus maybe more useful in this specific case.

> We are not arguing whether the C standard allows this. We are arguing whether the C compilers should do this.

The problem is that those are inextricably interlinked, because the compiler must still stay within the bounds of the standard, and still produce code with reasonably good performance.

> Stating that no code was removed has been extremely unhelpful to this conversation, regardless of whether you think it is a technically correct statement.

The point is not that it's a technically correct statement, the point is that that's not necessarily how the compiler "thinks", so it's often unhelpful in discussing compiler behaviour to talk about "removing code".

> In the generated machine code, a condition of a branch statement does not exist in the version with optimization, but does without it.

It just so happens that in this case, the compilation result without optimization was closer to the programmer's intention than with optimization. But the usefulness of this observation is severely limited because in other cases the exact opposite could be true. The programmer wrote something different than what they meant, and the compiler in some situation produced code that still matched the intention of the programmer ...

> The fact that this particular optimization relied on a case where the programmer specified a statement that depending on values not knowable to the compiler at the time of compilation may have resulted in undefined behavior or not makes this a poor optimization to carry out.

Except that if a C compiler avoided all optimizations for which this is true, a lot of code would be a lot slower. You seem to only be seeing some specific cases for which the performance difference is negligible, and the risk of the optimization is obvious to you, and your imprecise use of language doesn't make discussing this any easier. What you don't seem to realize is how much optimization a C compiler does that is perfectly safe that the compiler cannot easily, if at all, distinguish from this arguably dangerous case, which is why the compiler could only choose to either in many cases produce unnecessarily slow code, or use the current strategy and occasionally produce code that does something else than what the programmer had in mind.

> Perhaps you could actually address a point I've made instead of arguing over the words used. You are arguing over a technicality of the instead of the topic at hand.

Your point is incoherent because you are using imprecise language, which makes it difficult to address. That's why I am addressing your imprecise use of language first.