From: "Rémi Denis-Courmont via ffmpeg-devel" <ffmpeg-devel@ffmpeg.org>
To: "FFmpeg development discussions and patches"
<ffmpeg-devel@ffmpeg.org>,
"Martin Storsjö via ffmpeg-devel" <ffmpeg-devel@ffmpeg.org>,
"Rémi Denis-Courmont via ffmpeg-devel" <ffmpeg-devel@ffmpeg.org>
Cc: harish.rajaselvan@multicorewareinc.com,
"Martin Storsjö" <martin@martin.st>,
"Rémi Denis-Courmont" <remi@remlab.net>
Subject: [FFmpeg-devel] Re: [DISCUSSION] Adding ARM64EC support to FFmpeg
Date: Fri, 03 Oct 2025 17:32:50 +0300
Message-ID: <FB2707BE-DF44-4401-8BB2-5133F0DE1C98@remlab.net> (raw)
In-Reply-To: <4c7e8b2-7d9b-aea8-90ca-16da7bcd8ee@martin.st>
Le 3 octobre 2025 15:44:56 GMT+03:00, "Martin Storsjö via ffmpeg-devel" <ffmpeg-devel@ffmpeg.org> a écrit :
>First off, calling a C function, which turns out to be in x86_64 mode, will clobber those registers.
Will it? I thought code JITed from x86_64 to AArch64 could *not* access the reserved registers, and that was why they were forbidden (which barely makes sense to me).
I don't understand how this can be a problem except for green threads and long jumps. But that shouldn't be allowed to happen if you're using FFmpeg anyway - it could dead lock - regardless of the instruction set.
But again, the use case seems very unclear. I'm sure some people are using x86 FFmpeg on Arm, but how do you credibly end up with an AArch64 FFmpeg inside an Arm64EC process?
We shouldn't go out of our way to support an academic exercise or some weird proprietary insane code.
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next prev parent reply other threads:[~2025-10-03 14:33 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-22 10:04 [FFmpeg-devel] " harish.rajaselvan--- via ffmpeg-devel
2025-09-22 11:48 ` [FFmpeg-devel] " Martin Storsjö via ffmpeg-devel
2025-09-23 13:03 ` Harish Raja Selvan via ffmpeg-devel
2025-09-24 12:15 ` Martin Storsjö via ffmpeg-devel
2025-09-30 4:58 ` Harish Raja Selvan via ffmpeg-devel
2025-10-03 12:27 ` Martin Storsjö via ffmpeg-devel
2025-09-27 9:00 ` Rémi Denis-Courmont via ffmpeg-devel
2025-10-03 12:44 ` Martin Storsjö via ffmpeg-devel
2025-10-03 14:32 ` Rémi Denis-Courmont via ffmpeg-devel [this message]
2025-10-03 15:11 ` Martin Storsjö via ffmpeg-devel
2025-10-03 16:39 ` Rémi Denis-Courmont via ffmpeg-devel
2025-10-03 20:49 ` Stephen Hutchinson via ffmpeg-devel
2025-10-04 8:43 ` Rémi Denis-Courmont via ffmpeg-devel
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