Re: Removing register keyword

Don't let me bully you into removing it, if it really does something useful for performance.

But it will eventually disappear from the language, and it already (even in C++11 mode, per current VFX Platform specs) is a deprecation warning, which a lot of software build defaults intentionally turns into full-fledged errors.

Sorry about the duplicate PR, I should have scanned the list of pending requests before submitting.


> On Sep 30, 2016, at 4:37 PM, Ed Hanway <[email protected]> wrote:
> 
> We have multiple pending pull requests to remove the register keyword from the OpenEXR source.  I've looked at the code generated by gcc 4.8 with and without the register keyword, and, despite the claim that compilers don't care about the register keyword any more, the resulting object code for x86-64 is different, and slightly worse without the keyword.  That choice of compiler and platform isn't arbitrary -- it's consistent with the VFX reference platform.  
> 
> However, since the difference is relatively small, and may not be present at all for other compilers and target architectures, and people will keep submitting bugs and pull requests as long as the register keyword is there, I'm inclined to go ahead and remove the keyword anyway.  If anybody is that concerned about a performance regression on the order of a few percent in the half-from-float constructor, speak now or forever hold your peace.
> 
> -- 
> Ed Hanway
> 

--
Larry Gritz
[email protected]