GDC review process.

[Alex Rønne Petersen]

On 19-06-2012 22:40, Manu wrote:
> On 19 June 2012 21:19, Iain Buclaw <ibuclaw at ubuntu.com
> <mailto:ibuclaw at ubuntu.com>> wrote:
>
>     1) D Inline Asm and naked function support is raising far too many
>     alarm bells. So would just be easier to remove it and avoid all the
>     other comments on why we need middle-end and backend headers in gdc.
>
>
> Inline assembly has been relatively useless in GCC for years. Inline asm
> interferes with the optimisers ability to do a good job, which basically
> makes use of inline assembly self-defeating.
> The only time I ever need to use inline-asm is to interface an arch
> feature that has no API. As long as there are intrinsics for all the
> opcodes one might want, then it's better to use them.
>
> There are 2 operations that spring to mind that typically don't have
> intrinsics, or high level API's, which I always use asm to
> interface; the fine-grain manual manipulation of the flags register on
> PPC (ie, the '.' suite of opcodes), and conditional execution opcodes on
> ARM. Neither of these have high level expressions, and they are both
> relatively important.
> That said, as stated above, if use of this stuff is for performance,
> then using an inline-asm block will ruin the surrounding code anyway, so
> I almost always find I'm required to write the entire function in asm to
> achieve the expected result...
>
> I see no major loss to removing the inline assembler.
> I would like to know what the issue is though? Why are you compelled to
> remove it?
> I thought GCC optionally supported the microsoft asm syntax instead,
> which should make it syntactically consistent with D?

Not "Microsoft", but Intel syntax.

But GDC's inline assembly syntax is very different from DMD's: 
https://bitbucket.org/goshawk/gdc/wiki/UserDocumentation#!extended-assembler

-- 
Alex Rønne Petersen
alex at lycus.org
http://lycus.org