disound.cpp, sound.cpp, speaker.cpp: Use fill_n and resize to zero memory instead of memset (nw)

src/emu/disound.cpp

@@ -461,7 +461,7 @@ void device_mixer_interface::sound_stream_update(sound_stream &stream, stream_sa
 {
 	// clear output buffers
 	for (int output = 0; output < m_outputs; output++)
-		memset(outputs[output], 0, samples * sizeof(outputs[0][0]));
+		std::fill_n(outputs[output], samples, 0);
 
 	// loop over samples
 	const u8 *outmap = &m_outputmap[0];

src/emu/sound.cpp

@@ -410,7 +410,7 @@ void sound_stream::update_with_accounting(bool second_tick)
 		{
 			// if we have samples to move, do so for each output
 			if (output_bufindex > 0)
-				for (auto & output : m_output)
+				for (auto &output : m_output)
 				{
 					memmove(&output.m_buffer[0], &output.m_buffer[samples_to_lose], sizeof(output.m_buffer[0]) * (output_bufindex - samples_to_lose));
 				}
@@ -457,8 +457,8 @@ void sound_stream::apply_sample_rate_changes()
 
 	// clear out the buffer
 	if (m_max_samples_per_update)
-		for (auto & elem : m_output)
-			memset(&elem.m_buffer[0], 0, m_max_samples_per_update * sizeof(elem.m_buffer[0]));
+		for (auto &elem : m_output)
+			std::fill_n(&elem.m_buffer[0], m_max_samples_per_update, 0);
 }
 
 
@@ -474,7 +474,7 @@ void sound_stream::recompute_sample_rate_data()
 	{
 		m_sample_rate = 0;
 		// When synchronous, pick the sample rate for the inputs, if any
-		for (auto & input : m_input)
+		for (auto &input : m_input)
 		{
 			if (input.m_source != nullptr)
 			{
@@ -506,7 +506,7 @@ void sound_stream::recompute_sample_rate_data()
 	allocate_output_buffers();
 
 	// iterate over each input
-	for (auto & input : m_input)
+	for (auto &input : m_input)
 	{
 		// if we have a source, see if its sample rate changed
 
@@ -569,11 +569,8 @@ void sound_stream::allocate_resample_buffers()
 		m_resample_bufalloc = bufsize;
 
 		// iterate over outputs and realloc their buffers
-		for (auto & elem : m_input) {
-			unsigned int old_size = elem.m_resample.size();
-			elem.m_resample.resize(m_resample_bufalloc);
-			memset(&elem.m_resample[old_size], 0, (m_resample_bufalloc - old_size)*sizeof(elem.m_resample[0]));
-		}
+		for (auto &elem : m_input)
+			elem.m_resample.resize(m_resample_bufalloc, 0);
 	}
 }
 
@@ -593,11 +590,8 @@ void sound_stream::allocate_output_buffers()
 		m_output_bufalloc = bufsize;
 
 		// iterate over outputs and realloc their buffers
-		for (auto & elem : m_output) {
-			unsigned int old_size = elem.m_buffer.size();
-			elem.m_buffer.resize(m_output_bufalloc);
-			memset(&elem.m_buffer[old_size], 0, (m_output_bufalloc - old_size)*sizeof(elem.m_buffer[0]));
-		}
+		for (auto &elem : m_output)
+			elem.m_buffer.resize(m_output_bufalloc, 0);
 	}
 }
 
@@ -612,8 +606,8 @@ void sound_stream::postload()
 	recompute_sample_rate_data();
 
 	// make sure our output buffers are fully cleared
-	for (auto & elem : m_output)
-		memset(&elem.m_buffer[0], 0, m_output_bufalloc * sizeof(elem.m_buffer[0]));
+	for (auto &elem : m_output)
+		std::fill_n(&elem.m_buffer[0], m_output_bufalloc, 0);
 
 	// recompute the sample indexes to make sense
 	m_output_sampindex = m_attoseconds_per_sample ? m_device.machine().sound().last_update().attoseconds() / m_attoseconds_per_sample : 0;
@@ -684,7 +678,7 @@ stream_sample_t *sound_stream::generate_resampled_data(stream_input &input, u32
 	stream_sample_t *dest = &input.m_resample[0];
 	if (input.m_source == nullptr || input.m_source->m_stream->m_attoseconds_per_sample == 0)
 	{
-		memset(dest, 0, numsamples * sizeof(*dest));
+		std::fill_n(dest, numsamples, 0);
 		return &input.m_resample[0];
 	}
 

src/emu/speaker.cpp

@@ -79,8 +79,8 @@ void speaker_device::mix(s32 *leftmix, s32 *rightmix, int &samples_this_update,
 		samples_this_update = numsamples;
 
 		// reset the mixing streams
-		memset(leftmix, 0, samples_this_update * sizeof(*leftmix));
-		memset(rightmix, 0, samples_this_update * sizeof(*rightmix));
+		std::fill_n(leftmix, samples_this_update, 0);
+		std::fill_n(rightmix, samples_this_update, 0);
 	}
 	assert(samples_this_update == numsamples);