Re: [FFmpeg-devel] [PATCH] vp9: change order of operations in adapt_prob().

2016-10-24 Thread Ronald S. Bultje
Hi, On Fri, Oct 14, 2016 at 2:09 PM, James Zern wrote: > Ronald, > > On Fri, Oct 14, 2016 at 10:01 AM, Ronald S. Bultje > wrote: > > This is intended to workaround bug "665 Integer Divide Instruction May > > Cause Unpredictable Behavior" on some early AMD

Re: [FFmpeg-devel] [PATCH] vp9: change order of operations in adapt_prob().

2016-10-14 Thread James Zern
On Fri, Oct 14, 2016 at 11:54 AM, Ronald S. Bultje wrote: > Hi Michael, > > On Fri, Oct 14, 2016 at 2:31 PM, Michael Niedermayer > wrote: > >> On Fri, Oct 14, 2016 at 08:29:37PM +0200, Michael Niedermayer wrote: >> > On Fri, Oct 14, 2016 at 11:09:30AM

Re: [FFmpeg-devel] [PATCH] vp9: change order of operations in adapt_prob().

2016-10-14 Thread Ronald S. Bultje
Hi Michael, On Fri, Oct 14, 2016 at 2:31 PM, Michael Niedermayer wrote: > On Fri, Oct 14, 2016 at 08:29:37PM +0200, Michael Niedermayer wrote: > > On Fri, Oct 14, 2016 at 11:09:30AM -0700, James Zern wrote: > > > Ronald, > > > > > > On Fri, Oct 14, 2016 at 10:01 AM,

Re: [FFmpeg-devel] [PATCH] vp9: change order of operations in adapt_prob().

2016-10-14 Thread James Zern
On Fri, Oct 14, 2016 at 11:31 AM, Michael Niedermayer wrote: > On Fri, Oct 14, 2016 at 08:29:37PM +0200, Michael Niedermayer wrote: >> On Fri, Oct 14, 2016 at 11:09:30AM -0700, James Zern wrote: >> > Ronald, >> > >> > On Fri, Oct 14, 2016 at 10:01 AM, Ronald S. Bultje

Re: [FFmpeg-devel] [PATCH] vp9: change order of operations in adapt_prob().

2016-10-14 Thread Michael Niedermayer
On Fri, Oct 14, 2016 at 08:29:37PM +0200, Michael Niedermayer wrote: > On Fri, Oct 14, 2016 at 11:09:30AM -0700, James Zern wrote: > > Ronald, > > > > On Fri, Oct 14, 2016 at 10:01 AM, Ronald S. Bultje > > wrote: > > > This is intended to workaround bug "665 Integer Divide

Re: [FFmpeg-devel] [PATCH] vp9: change order of operations in adapt_prob().

2016-10-14 Thread Michael Niedermayer
On Fri, Oct 14, 2016 at 11:09:30AM -0700, James Zern wrote: > Ronald, > > On Fri, Oct 14, 2016 at 10:01 AM, Ronald S. Bultje wrote: > > This is intended to workaround bug "665 Integer Divide Instruction May > > Cause Unpredictable Behavior" on some early AMD CPUs, which

Re: [FFmpeg-devel] [PATCH] vp9: change order of operations in adapt_prob().

2016-10-14 Thread James Zern
Ronald, On Fri, Oct 14, 2016 at 10:01 AM, Ronald S. Bultje wrote: > This is intended to workaround bug "665 Integer Divide Instruction May > Cause Unpredictable Behavior" on some early AMD CPUs, which causes a > div-by-zero in this codepath, such as reported in Mozilla bug

[FFmpeg-devel] [PATCH] vp9: change order of operations in adapt_prob().

2016-10-14 Thread Ronald S. Bultje
This is intended to workaround bug "665 Integer Divide Instruction May Cause Unpredictable Behavior" on some early AMD CPUs, which causes a div-by-zero in this codepath, such as reported in Mozilla bug #1293996. Note that this isn't guaranteed to fix the bug, since a compiler is free to reorder