[MLton] Re: [MLton-commit] r7458

[Wesley W. Terpstra]

On Mon, May 10, 2010 at 8:19 PM, Matthew Fluet <matthew.fluet at gmail.com>wrote:

> > I really want to hurt whoever decided to take this idiom away. There are
> no
> > alternatives except calling out to memcpy (or similar) via a char*. The
> cost
> > to performance for a simple endian-swap is absurd.
> Looking at the assembly code using memcpy vs. using a union with
> __attribute__((__may_alias__)), they are nearly identical at all but
> -O0.  Certainly, no explicit memcpy calls, and sometimes the code that
> had memcpy is compiled to a shorter assembly sequence.
>
So gcc optimizes the memcpy away? Interesting/Impressive.
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