[Nasm-devel] nasm-2.14rc5 gives error where nasm-2.13.03 doesn't

[<bal...@un...>]

hello

I don't know if this is actually a problem with nasm or ffmpeg: so
apologies if I am reporting to the wrong list

The problem is with the current nasm rc version 2.14rc5 (so something
which is still to be officially released); I'm sending this just as a
possible heads up for the nasm developers...

While building the latest official ffmpeg release (ffmpeg-4.0.1),
using nasm-2.14rc5 I get:

----8<----
nasm -f elf64 -DPIC -g -F dwarf -I./ -I.// -Ilibavcodec/x86/ -Pconfig.asm -MD libavcodec/x86/h264_deblock.d  -o libavcodec/x86/h264_deblock.o libavcodec/x86/h264_deblock.asm
libavcodec/x86/h264_deblock.asm:1392: error: symbol `ff_h264_loop_filter_strength_mmxext.bidir' undefined
libavutil/x86/x86inc.asm:683: ... from macro `jne' defined here
libavcodec/x86/h264_deblock.asm:1392: warning: label `..@12237.branch_instr' changed during code generation

[...a bunch of similar warnings...]

---->8----

OTOH, no problem whatsoever if I use nasm-2.13.03

(Both nasm-2.14rc5 and nasm-2.13.03 built from source with:

--prefix=/opt/stow.d/versions/nasm-${version}/usr
--libdir=/opt/stow.d/versions/nasm-${version}/usr/lib64
--infodir=/opt/stow.d/versions/nasm-${version}/usr/share/info

)

Here is a scriptlett which you can edit/use to reproduce the problem:

----8<----
#!/bin/sh
mkdir -p /tmp/ffmpeg-test  # create a sandbox
cd /tmp/ffmpeg-test
rm -f ./ffmpeg-4.0.1.tar.bz2
# get the ffmpeg tarball
wget http://ffmpeg.org/releases/ffmpeg-4.0.1.tar.bz2
rm -rf ./ffmpeg-4.0.1
# unpack
tar axf ffmpeg-4.0.1.tar.bz2
cd ffmpeg-4.0.1
set -x      # some verbosity
./configure # use defaults

######################################################
# this fails for 2.14rc5 while succeeds for 2.13.03. #
######################################################
nasm -f elf64 -DPIC -g -F dwarf -I./ -I.// -Ilibavcodec/x86/ \
     -Pconfig.asm -MD libavcodec/x86/h264_deblock.d  \
     -o libavcodec/x86/h264_deblock.o libavcodec/x86/h264_deblock.asm
# see which nasm is in use
nasm --version
---->8----

Apologies if this report is inappropriate

ciao
gabriele