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Re: Deprecating basic asm in a function - What now?


On 22/06/16 09:59, Florian Weimer wrote:
> On 06/20/2016 07:40 PM, Andrew Haley wrote:
>> On 20/06/16 18:36, Michael Matz wrote:
>>> I see zero gain by deprecating them and only churn.  What would be the 
>>> advantage again?
>>
>> Correctness.  It is very likely that many of these basic asms are not
>> robust in the face of compiler changes because they don't declare
>> their dependencies and therefore work only by accident.
> 
> But the correctness problem is much more severe with extended asm.  With
> basic asm, the compiler can be conservative.  With extended asm, there
> is an expectation that it is not, and yet many of the constraints out
> there are slightly wrong and can lead to breakage any time.

Yes, that's true.  However, at least in the case of extended asm there
is a chance that the programmer has thought about it.

But anyway, the decision has been made.  None of this matters.

Andrew.



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