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Re: [PATCH] Fix PR libstdc++/19510: Uninitialized variable in some iterators


Mark Mitchell <mark@codesourcery.com> writes:

| Gabriel Dos Reis wrote:
| 
| > In the typical case where a singular iterator is created, it is
| > inlined and if the compiler cannot figure out that those inlined
| > initialization can be efficiently turned into something else, then
| > it is a compiler bug.
| 
| I'm not confident that the compiler will always be able to figure this out.

I based my analysis from application programmer and library users
point of view.

Do you have any real world example to submit for scrunity?

| In any case, why should we take that chance?
| 
| If someone runs a benchmark of G++ & V3 vis a vis some other system,
| and the benchmark shows that we're slower, we lose.  It doesn't matter
| whether that's because of the compiler or the library.  No, I'm not
| arguing that we should hand code the entire library in some special
| style that's particularly amenable to G++.  I am arguing, however,
| that inserting code to do something that is on most systems at best

| pointless, and quite possibly harmful, is a mistake.

What is a possibly harmful, a mistake is this meaningless discussion
with you about benchmarks on singular iterator values.  I understand
you value speed over correctness.  We just have to agree to disagree.

-- Gaby


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