[pulseaudio-discuss] [PATCH v3] netbsd: Stop depending upon nonstandard __WORDSIZE

[David Henningsson]

On 2015-12-16 10:40, Kamil Rytarowski wrote:
> There is no way to check CPU type in a portable way across ABIs.
>
> Go for pa_mult_s16_volume() version without need for int64_t.
> It's actually the same as in src/tests/mult-s16-test.c.
>
> This change fixes build on NetBSD.
> ---
>   src/pulsecore/sample-util.h | 5 -----
>   src/tests/mult-s16-test.c   | 9 ++-------
>   2 files changed, 2 insertions(+), 12 deletions(-)
>
> diff --git a/src/pulsecore/sample-util.h b/src/pulsecore/sample-util.h
> index c817bc9..9862938 100644
> --- a/src/pulsecore/sample-util.h
> +++ b/src/pulsecore/sample-util.h
> @@ -55,10 +55,6 @@ void pa_deinterleave(const void *src, void *dst[], unsigned channels, size_t ss,
>   void pa_sample_clamp(pa_sample_format_t format, void *dst, size_t dstr, const void *src, size_t sstr, unsigned n);
>   
>   static inline int32_t pa_mult_s16_volume(int16_t v, int32_t cv) {
> -#if __WORDSIZE == 64 || ((ULONG_MAX) > (UINT_MAX))
> -    /* Multiply with 64 bit integers on 64 bit platforms */
> -    return (v * (int64_t) cv) >> 16;
> -#else

Instead of dropping this (which looks like an optimisation), can't you 
just do - as a quick fix if nothing else:

#if (defined(__WORDSIZE) && (__WORDSIZE == 64)) || ((ULONG_MAX) > 
(UINT_MAX))

Will that allow netbsd to build?

But, according to the gcc docs [1], "if <symbol> is not defined, it will 
be interpreted as having the value zero".
So I'm still not understanding why the current code breaks on netbsd? 
Are you using some other compiler which behaves differently?

[1] https://gcc.gnu.org/onlinedocs/cpp/Defined.html

>       /* Multiplying the 32 bit volume factor with the
>        * 16 bit sample might result in an 48 bit value. We
>        * want to do without 64 bit integers and hence do
> @@ -68,7 +64,6 @@ static inline int32_t pa_mult_s16_volume(int16_t v, int32_t cv) {
>       int32_t hi = cv >> 16;
>       int32_t lo = cv & 0xFFFF;
>       return ((v * lo) >> 16) + (v * hi);
> -#endif
>   }
>   
>   pa_usec_t pa_bytes_to_usec_round_up(uint64_t length, const pa_sample_spec *spec);
> diff --git a/src/tests/mult-s16-test.c b/src/tests/mult-s16-test.c
> index d2a351c..20ad107 100644
> --- a/src/tests/mult-s16-test.c
> +++ b/src/tests/mult-s16-test.c
> @@ -93,13 +93,8 @@ int main(int argc, char *argv[]) {
>       if (!getenv("MAKE_CHECK"))
>           pa_log_set_level(PA_LOG_DEBUG);
>   
> -#if __WORDSIZE == 64 || ((ULONG_MAX) > (UINT_MAX))
> -    pa_log_debug("This seems to be 64-bit code.");
> -#elif  __WORDSIZE == 32
> -    pa_log_debug("This seems to be 32-bit code.");
> -#else
> -    pa_log_debug("Don't know if this is 32- or 64-bit code.");
> -#endif
> +    pa_log_debug("On this platform, integer size is %zu and long size is %zu",
> +            sizeof(int), sizeof(long));
>   
>       s = suite_create("Mult-s16");
>       tc = tcase_create("mult-s16");