On 25/07/2018 9:23 PM, Zheng (Vic) Luo wrote:
On Wednesday, 25 July 2018 at 09:16:19 UTC, rikki cattermole wrote:
On 25/07/2018 8:59 PM, Zheng (Vic) Luo wrote:
Minimal example in D: https://run.dlang.io/is/EYVTzb. Affects at
least dmd and ldc.
https://run.dlang.io/is/8tPOVX
Note that switch void* to ubyte* won't matter once its extern(C)'d.
My version (_memcpy_impl2) is just the regular old memcpy without
optimizations. Your example is syntax sugar for a function call.
There is no guarantee that a compiler (in a future version or after
enabling some optimization flags) will not optimize _memcpy_impl2 into
"call memset". Maybe it just happens that the optimizer is not smart
enough to optimize this, because nothing with -beeterC prohibits the
compiler to do so.
You misunderstand.
It isn't optimizing anything.
You requested the call to memcpy, explicitly when you said 'I want this
copied ASAP'.
By the looks, the spec doesn't clearly explain this properly.
