[pulseaudio-discuss] [PATCH] Fix test-suite failure on Alpha

[Arun Raghavan]

On 9 September 2015 at 15:19, Michael Cree <mcree at orcon.net.nz> wrote:
> Pulseaudio fails to build on the Alpha architecture due to a failure
> in the volume-test of the test suite.  I had reported this to the
> Debian bug tracker [1] but the maintainer has asked that I forward the
> patch to this mail list.  The failure in volume-test occurs because it
> is compiled with -ffast-math which implies -ffinite-math-only of which
> the gcc manual states that it optimizes for floating-point arithmetic
> with the assumption that arguments and results are not NaNs or
> +/-infinity, and futher notes that it may result in incorrect output.
> On the Alpha platform that is somewhat an understatement as the use of
> non-finite floating-point arithmetic with -ffinite-math-only results in
> a floating-point exception and the termination of the program.
>
> The volume-test converts volumes into decibels (so a zero volume
> becomes a negative infinity) and proceeds to add two volumes (in
> decibels), thus does arithmetic with non-finite floating point numbers
> despite being compiled with -ffast-math!
>
> I attach a patch that protects against the arithmetic with non-finite
> numbers for your consideration.  With that patch the test-suite passes
> on Alpha.
>
> Cheers
> Michael.
>
> [1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=798248

Thanks for the fix! I've pushed this out to our next branch (since
we're frozen for the 7.0 release, it'll only make it out in 8.0).

As a tip, it's easier for us to merge patches if you commit them
locally with a proper commit message, and then use git format-patch to
send in something we can just review and merge.

Cheers,
Arun