From 6f8cf73f54c4b1f80d69ecd30d269f16df70ef6e Mon Sep 17 00:00:00 2001
From: wm4 <wm4@nowhere>
Date: Thu, 30 Nov 2017 01:14:33 +0100
Subject: ao: simplify hack for float atomics

stdatomic.h defines no atomic_float typedef. We can't just use _Atomic
unconditionally, because we support compilers without C11 atomics. So
just create a custom atomic_float typedef in the wrapper, which uses
_Atomic in the C11 code path.
---
 audio/out/ao.c       | 16 ++--------------
 audio/out/internal.h |  4 ++--
 osdep/atomic.h       |  3 +++
 3 files changed, 7 insertions(+), 16 deletions(-)

diff --git a/audio/out/ao.c b/audio/out/ao.c
index c40eae1b92..7c2100c7d2 100644
--- a/audio/out/ao.c
+++ b/audio/out/ao.c
@@ -642,19 +642,7 @@ void ao_print_devices(struct mpv_global *global, struct mp_log *log)
 
 void ao_set_gain(struct ao *ao, float gain)
 {
-    uint_least32_t v = 0;
-    assert(sizeof(gain) <= sizeof(v));
-    memcpy(&v, &gain, sizeof(gain));
-    atomic_store(&ao->gain_fi, v);
-}
-
-static float ao_get_gain(struct ao *ao)
-{
-    uint_least32_t v = atomic_load_explicit(&ao->gain_fi, memory_order_relaxed);
-    float gain;
-    assert(sizeof(gain) <= sizeof(v));
-    memcpy(&gain, &v, sizeof(gain));
-    return gain;
+    atomic_store(&ao->gain, gain);
 }
 
 #define MUL_GAIN_i(d, num_samples, gain, low, center, high)                     \
@@ -669,7 +657,7 @@ static float ao_get_gain(struct ao *ao)
 
 static void process_plane(struct ao *ao, void *data, int num_samples)
 {
-    float gain = ao_get_gain(ao);
+    float gain = atomic_load_explicit(&ao->gain, memory_order_relaxed);
     int format = af_fmt_from_planar(ao->format);
     if (gain == 1.0f)
         return;
diff --git a/audio/out/internal.h b/audio/out/internal.h
index 9826630108..33e8a8c6a9 100644
--- a/audio/out/internal.h
+++ b/audio/out/internal.h
@@ -70,8 +70,8 @@ struct ao {
     // Internal events (use ao_request_reload(), ao_hotplug_event())
     atomic_int events_;
 
-    // Float gain multiplicator, reinterpret-casted to int.
-    atomic_uint_least32_t gain_fi;
+    // Float gain multiplicator
+    mp_atomic_float gain;
 
     int buffer;
     double def_buffer;
diff --git a/osdep/atomic.h b/osdep/atomic.h
index 1d3e158afa..a5608fa78a 100644
--- a/osdep/atomic.h
+++ b/osdep/atomic.h
@@ -24,6 +24,7 @@
 
 #if HAVE_STDATOMIC
 #include <stdatomic.h>
+typedef _Atomic float mp_atomic_float;
 #else
 
 // Emulate the parts of C11 stdatomic.h needed by mpv.
@@ -36,6 +37,8 @@ typedef struct { long long v;          } atomic_llong;
 typedef struct { uint_least32_t v;     } atomic_uint_least32_t;
 typedef struct { unsigned long long v; } atomic_ullong;
 
+typedef struct { float v;              } mp_atomic_float;
+
 #define ATOMIC_VAR_INIT(x) \
     {.v = (x)}
 
-- 
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