[GSoC] 'Independency of D from the C Standard Library' progress and update thread
j at j.nl
Thu Sep 5 23:57:39 UTC 2019
On Thursday, 5 September 2019 at 22:56:30 UTC, H. S. Teoh wrote:
> On Thu, Sep 05, 2019 at 09:50:04PM +0000, Stefanos Baziotis via
> Digitalmars-d wrote: [...]
>> - For the first 2, let me thank again Manu and Johan helped
>> who me
>> realize them! Note also that we don't currently know of a
>> way of
>> informing LLVM or GCC about the semantics and thus get this
>> optimization. The closest thing we have is LLVM recognizing
>> that a
>> function does what e.g. memcpy() does by name. Which is a bad
>> assumption to build upon.
> That's pretty scary that LLVM does that. It shakes my
> confidence in LLVM a little. OTOH, the identifier "memcpy" is
> pretty unique and practically universally understood to mean
> C's implementation of it, so it's a reasonably safe assumption.
FYI, GCC does the same.
(the opposite too: converting a copying pattern into memcpy is an
optimization performed by LLVM, GCC, and MSVC)
More information about the Digitalmars-d