Commit c21765e8 authored by Tim-Philipp Müller's avatar Tim-Philipp Müller 🐠

rtpulpfecdec: don't use __builtin_ctzll unconditionally

Fixes build with MSVC, and possibly other compilers too.
parent 14f45c7b
......@@ -276,6 +276,30 @@ gst_rtp_ulpfec_dec_recover_from_storage (GstRtpUlpFecDec * self,
return gst_buffer_ref (info->rtp.buffer);
}
/* __has_builtin only works with clang, so test compiler version for gcc */
/* Intel compiler and MSVC probably have their own things as well */
#if defined(__has_builtin) && __has_builtin(__builtin_ctzll)
#define rtp_ulpfec_ctz64 __builtin_ctzll
#elif defined(__GNUC__) && __GNUC__ >= 4
#define rtp_ulpfec_ctz64 __builtin_ctzll
#else
static inline gint
rtp_ulpfec_ctz64_inline (guint64 mask)
{
gint nth_bit = 0;
do {
if ((mask & 1))
return nth_bit;
mask = mask >> 1;
} while (++nth_bit < 64);
return -1; /* should not be reached, since mask must not be 0 */
}
#define rtp_ulpfec_ctz64 rtp_ulpfec_ctz64_inline
#endif
static GstBuffer *
gst_rtp_ulpfec_dec_recover (GstRtpUlpFecDec * self, guint32 ssrc, gint media_pt,
guint8 * dst_pt, guint16 * dst_seq)
......@@ -308,7 +332,7 @@ gst_rtp_ulpfec_dec_recover (GstRtpUlpFecDec * self, guint32 ssrc, gint media_pt,
/* Do we have any 1s? Checking if current FEC packet can be used for recovery */
if (0 != missing_packets_mask) {
guint trailing_zeros = __builtin_ctzll (missing_packets_mask);
guint trailing_zeros = rtp_ulpfec_ctz64 (missing_packets_mask);
/* Is it the only 1 in the mask? Checking if we lacking single packet in
* that case FEC packet can be used for recovery */
......@@ -620,4 +644,7 @@ gst_rtp_ulpfec_dec_class_init (GstRtpUlpFecDecClass * klass)
g_object_class_install_properties (gobject_class, N_PROPERTIES,
klass_properties);
g_assert (rtp_ulpfec_ctz64 (G_GUINT64_CONSTANT (0x1)) == 0);
g_assert (rtp_ulpfec_ctz64 (G_GUINT64_CONSTANT (0x8000000000000000)) == 63);
}
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