[FFmpeg-devel] [inline assembly compliance] Issues and patches

Michael Niedermayer michael at niedermayer.cc
Sat Apr 4 19:55:27 EEST 2020


On Sat, Apr 04, 2020 at 12:28:43PM +0200, FRÉDÉRIC RECOULES wrote:
> Thank you for your answers. 
> 
> As you have pointed out, these patches are full of unrelated changes that are not important for safety. 
> Most of them were never intended to be posted here, the diff we submitted was the one of an 
> experimental branch and we apologize to have made such a mistake. 
> We will resubmit the patch with only essential patches in a more appropriate format very soon 
> (git format-patch). 
> 
> @Michael These errors come with the Clang compiler, aren't they? 

yes, seems this was
clang version 4.0.0 (trunk 283753)

i can retest and find a mininal command line for configure which triggers this
in case you cannot reproduce it ?


> We are aware that support for inline assembly may differ from one compiler to another 
> despite the "higly-compatibility" that is stated. The safety patches we are proposing 
> do not rely on them. 
> 
> @Carl @Kieran So far, we passed the FATE tests. 
> The output is slightly different because we have merged contiguous assembly statement 
> such that the compiler can no longer insert instruction between them, but the differences 
> are only instruction swaps A.B.C -> B.A.C. 

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

There will always be a question for which you do not know the correct answer.
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