On Thu, 9 Oct 2008, Brandon Casey wrote:
> "Possible" benefits:
>
> 1) more concise, so it improves readability in most cases
> 2) gives compiler more flexibility when optimizing
Beware beware. At some point this wasn't a gain at all with some gcc
versions as it was stupid enough to construct a temporary object on the
stack corresponding to "{ 0, }" and afterward do the assignment by
*copying* this object to a different stack slot corresponding to the
actual variable instead of constructing the initial value in place.
Also note that, on the other hand, gcc is smart enough to optimize a
memset() using a constant size and value already by doing appropriate
code replacement inline. I've also seen cases where gcc did the
opposite and replaced an explicit assignment like your patch does with
an actual call to memset() when optimizing for size.
So when claiming flexibility for the compiler to better optimize things,
please make sure this is really what is happening through assembly dump
inspection.
Nicolas
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