Remove bit fields to improve performance

uint16_t enabled is (mostly) changed to bool in a separate CL

Change-Id: Ied9f8c034b2479cee9a8778cee7b8ff92ae75b7b

3 files changed, 32 insertions, 21 deletions

diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index 0292bc3..2e2834c 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -2295,7 +2295,7 @@ AudioFlinger::PlaybackThread::mixer_state AudioFlinger::MixerThread::prepareTrac
 
                 uint16_t sendLevel = cblk->getSendLevel_U4_12();
                 // send level comes from shared memory and so may be corrupt
-                if (sendLevel >= MAX_GAIN_INT) {
+                if (sendLevel > MAX_GAIN_INT) {
                     ALOGV("Track send level out of range: %04X", sendLevel);
                     sendLevel = MAX_GAIN_INT;
                 }
@@ -2316,25 +2316,21 @@ AudioFlinger::PlaybackThread::mixer_state AudioFlinger::MixerThread::prepareTrac
             }
 
             // Convert volumes from 8.24 to 4.12 format
-            int16_t left, right, aux;
             // This additional clamping is needed in case chain->setVolume_l() overshot
-            uint32_t v_clamped = (vl + (1 << 11)) >> 12;
-            if (v_clamped > MAX_GAIN_INT) v_clamped = MAX_GAIN_INT;
-            left = int16_t(v_clamped);
-            v_clamped = (vr + (1 << 11)) >> 12;
-            if (v_clamped > MAX_GAIN_INT) v_clamped = MAX_GAIN_INT;
-            right = int16_t(v_clamped);
+            vl = (vl + (1 << 11)) >> 12;
+            if (vl > MAX_GAIN_INT) vl = MAX_GAIN_INT;
+            vr = (vr + (1 << 11)) >> 12;
+            if (vr > MAX_GAIN_INT) vr = MAX_GAIN_INT;
 
-            if (va > MAX_GAIN_INT) va = MAX_GAIN_INT;
-            aux = int16_t(va);
+            if (va > MAX_GAIN_INT) va = MAX_GAIN_INT;   // va is uint32_t, so no need to check for -
 
             // XXX: these things DON'T need to be done each time
             mAudioMixer->setBufferProvider(name, track);
             mAudioMixer->enable(name);
 
-            mAudioMixer->setParameter(name, param, AudioMixer::VOLUME0, (void *)left);
-            mAudioMixer->setParameter(name, param, AudioMixer::VOLUME1, (void *)right);
-            mAudioMixer->setParameter(name, param, AudioMixer::AUXLEVEL, (void *)aux);
+            mAudioMixer->setParameter(name, param, AudioMixer::VOLUME0, (void *)vl);
+            mAudioMixer->setParameter(name, param, AudioMixer::VOLUME1, (void *)vr);
+            mAudioMixer->setParameter(name, param, AudioMixer::AUXLEVEL, (void *)va);
             mAudioMixer->setParameter(
                 name,
                 AudioMixer::TRACK,
diff --git a/services/audioflinger/AudioMixer.cpp b/services/audioflinger/AudioMixer.cpp
index f3bf953..020d62a 100644
--- a/services/audioflinger/AudioMixer.cpp
+++ b/services/audioflinger/AudioMixer.cpp
@@ -257,6 +257,7 @@ void AudioMixer::setParameter(int name, int target, int param, void *value)
             }
             break;
         case AUXLEVEL:
+            //assert(0 <= valueInt && valueInt <= MAX_GAIN_INT);
             if (track.auxLevel != valueInt) {
                 ALOGV("setParameter(VOLUME, AUXLEVEL: %04x)", valueInt);
                 track.prevAuxLevel = track.auxLevel << 16;
@@ -565,7 +566,7 @@ void AudioMixer::volumeStereo(track_t* t, int32_t* out, size_t frameCount, int32
     const int16_t vr = t->volume[1];
 
     if (CC_UNLIKELY(aux != NULL)) {
-        const int16_t va = (int16_t)t->auxLevel;
+        const int16_t va = t->auxLevel;
         do {
             int16_t l = (int16_t)(*temp++ >> 12);
             int16_t r = (int16_t)(*temp++ >> 12);
diff --git a/services/audioflinger/AudioMixer.h b/services/audioflinger/AudioMixer.h
index c3174ae..b210212 100644
--- a/services/audioflinger/AudioMixer.h
+++ b/services/audioflinger/AudioMixer.h
@@ -127,32 +127,46 @@ private:
 
         int32_t     prevVolume[MAX_NUM_CHANNELS];
 
+        // 16-byte boundary
+
         int32_t     volumeInc[MAX_NUM_CHANNELS];
-        int32_t     auxLevel;
         int32_t     auxInc;
         int32_t     prevAuxLevel;
 
+        // 16-byte boundary
+
+        int16_t     auxLevel;       // 0 <= auxLevel <= MAX_GAIN_INT, but signed for mul performance
         uint16_t    frameCount;
 
-        uint8_t     channelCount : 4;
-        uint8_t     enabled      : 1;
-        uint8_t     reserved0    : 3;
-        uint8_t     format;
-        uint32_t    channelMask;
+        uint8_t     channelCount;   // 1 or 2, redundant with (needs & NEEDS_CHANNEL_COUNT__MASK)
+        uint8_t     format;         // always 16
+        uint16_t    enabled;        // actually bool
+        uint32_t    channelMask;    // currently under-used
 
         AudioBufferProvider*                bufferProvider;
-        mutable AudioBufferProvider::Buffer buffer;
+
+        // 16-byte boundary
+
+        mutable AudioBufferProvider::Buffer buffer; // 8 bytes
 
         hook_t      hook;
         const void* in;             // current location in buffer
 
+        // 16-byte boundary
+
         AudioResampler*     resampler;
         uint32_t            sampleRate;
         int32_t*           mainBuffer;
         int32_t*           auxBuffer;
 
+        // 16-byte boundary
+
         uint64_t    localTimeFreq;
 
+        int64_t     padding;
+
+        // 16-byte boundary
+
         bool        setResampler(uint32_t sampleRate, uint32_t devSampleRate);
         bool        doesResample() const { return resampler != NULL; }
         void        resetResampler() { if (resampler != NULL) resampler->reset(); }