FTBFS with NEON on arm64

[Logan Rosen]

The latest version of libav in utopic-proposed/unstable (6:10.1-1) fails to build from source with NEON enabled. The relevant build log is here: https://launchpadlibrarian.net/176152432/buildlog_ubuntu-utopic-arm64.libav_6%3A10.1-1_FAILEDTOBUILD.txt.gz

One suggestion on IRC was to simply disable NEON on arm64 for libav, but there might be another possible approach to fixing this.

[Reinhard Tartler (siretart)]

Can someone please if this patch fixes this problem?

diff --git a/configure b/configure
index 05acff5..4d5d2b5 100755
--- a/configure
+++ b/configure
@@ -3652,6 +3652,11 @@ EOF

     [ $target_os != win32 ] && enabled_all armv6t2 shared !pic && enable_weak_pic

+ # https://bugs.launchpad.net/bugs/1323144
+ if enabled pic; then
+ disable neon
+ fi
+
 elif enabled mips; then

     check_inline_asm loongson '"dmult.g $1, $2, $3"'

[Reinhard Tartler (siretart)]

I believe the linked branch fixes this issue, but I'd appreciate testing (I don't have the hardware available to test myself)

[Reinhard Tartler (siretart)]

This may be the correct fix that does not require disabling neon:

https://git.libav.org/?p=libav.git;a=commitdiff;h=34fb994d9340313b0d247899a4a7a97cc010df92;hp=e780c3daafe0588e035e752c771ebfcd2201746a

Again, testing appreciated

[Reinhard Tartler (siretart)]

libav (6:10.1-1ubuntu1) utopic; urgency=low

  * add patch to fix FTBFS on ppc64el, LP: #1263802
  * add patch to fix FTBFS on arm64, LP: #1323144
 -- Reinhard Tartler <email address hidden> Thu, 29 May 2014 07:34:56 -0400