Bug#1033368: nasm: use i386-baseline compatible NOP alignment
Source: x265
Version: 3.5-2
Severity: wishlist
Dear Maintainer,
The use of nasm 'ALIGNMODE p6'[1] in upstream's x265 source results in the nasm
assembler emitting multi-byte no-op (NOPL) instructions that are not compatible
with all systems within Debian's i386 baseline (for example: Geode LX does not
support those opcodes).
It looks like this originates from within an upstream change in Y2017.
By adjusting to 'ALIGNMODE k8' (the previous setting upstream), compatibility
with those systems could be restored (multi-byte NOPs are no longer emitted).
I'll offer a merge request on Salsa with the suggested change.
Thanks,
James
(for context: this bug was discovered while researching multi-byte NOP opcodes
as part of #1005863)
[1] - https://www.nasm.us/xdoc/2.16.01/html/nasmdoc6.html#section-6.2
[2] - https://sources.debian.org/src/libass/1%3A0.17.1-1/libass/x86/x86inc.asm/#L904
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