Moved baseband temporary buffers back into class member variables.

Significant performance hit when declaring on stack. C++ wants to initialize std::array or even raw array with element constructors, was resulting in ~7% CPU utilization, for a buffer that was immediately written over anyway.

firmware/baseband/proc_ais.cpp

@@ -36,12 +36,6 @@ AISProcessor::AISProcessor() {
 void AISProcessor::execute(const buffer_c8_t& buffer) {
 	/* 2.4576MHz, 2048 samples */
 
-	std::array<complex16_t, 512> dst;
-	const buffer_c16_t dst_buffer {
-		dst.data(),
-		dst.size()
-	};
-
 	const auto decim_0_out = decim_0.execute(buffer, dst_buffer);
 	const auto decim_1_out = decim_1.execute(decim_0_out, dst_buffer);
 	const auto decimator_out = decim_1_out;

firmware/baseband/proc_ais.hpp

@@ -47,6 +47,12 @@ public:
 	void execute(const buffer_c8_t& buffer) override;
 
 private:
+	std::array<complex16_t, 512> dst;
+	const buffer_c16_t dst_buffer {
+		dst.data(),
+		dst.size()
+	};
+
 	dsp::decimate::FIRC8xR16x24FS4Decim8 decim_0;
 	dsp::decimate::FIRC16xR16x32Decim8 decim_1;
 	dsp::matched_filter::MatchedFilter mf { baseband::ais::rrc_taps_38k4_4t_p, 2 };

firmware/baseband/proc_am_audio.cpp

@@ -28,12 +28,6 @@ void NarrowbandAMAudio::execute(const buffer_c8_t& buffer) {
 		return;
 	}
 
-	std::array<complex16_t, 512> dst;
-	const buffer_c16_t dst_buffer {
-		dst.data(),
-		dst.size()
-	};
-
 	const auto decim_0_out = decim_0.execute(buffer, dst_buffer);
 	const auto decim_1_out = decim_1.execute(decim_0_out, dst_buffer);
 	const auto channel_out = channel_filter.execute(decim_1_out, dst_buffer);
@@ -42,11 +36,6 @@ void NarrowbandAMAudio::execute(const buffer_c8_t& buffer) {
 	feed_channel_stats(channel_out);
 	channel_spectrum.feed(channel_out, channel_filter_pass_f, channel_filter_stop_f);
 
-	const buffer_s16_t work_audio_buffer {
-		(int16_t*)dst.data(),
-		sizeof(*dst.data()) * dst.size()
-	};
-
 	auto audio = demod.execute(channel_out, work_audio_buffer);
 
 	audio_hpf.execute_in_place(audio);

firmware/baseband/proc_am_audio.hpp

@@ -40,6 +40,16 @@ public:
 	void on_message(const Message* const message) override;
 
 private:
+	std::array<complex16_t, 512> dst;
+	const buffer_c16_t dst_buffer {
+		dst.data(),
+		dst.size()
+	};
+	const buffer_s16_t work_audio_buffer {
+		(int16_t*)dst.data(),
+		sizeof(*dst.data()) * dst.size()
+	};
+
 	dsp::decimate::FIRC8xR16x24FS4Decim8 decim_0;
 	dsp::decimate::FIRC16xR16x32Decim8 decim_1;
 	dsp::decimate::FIRAndDecimateComplex channel_filter;

firmware/baseband/proc_nfm_audio.cpp

@@ -29,12 +29,6 @@ void NarrowbandFMAudio::execute(const buffer_c8_t& buffer) {
 		return;
 	}
 
-	std::array<complex16_t, 512> dst;
-	const buffer_c16_t dst_buffer {
-		dst.data(),
-		dst.size()
-	};
-
 	const auto decim_0_out = decim_0.execute(buffer, dst_buffer);
 	const auto decim_1_out = decim_1.execute(decim_0_out, dst_buffer);
 	const auto channel_out = channel_filter.execute(decim_1_out, dst_buffer);
@@ -42,11 +36,6 @@ void NarrowbandFMAudio::execute(const buffer_c8_t& buffer) {
 	feed_channel_stats(channel_out);
 	channel_spectrum.feed(channel_out, channel_filter_pass_f, channel_filter_stop_f);
 
-	const buffer_s16_t work_audio_buffer {
-		(int16_t*)dst.data(),
-		sizeof(*dst.data()) * dst.size()
-	};
-
 	auto audio = demod.execute(channel_out, work_audio_buffer);
 
 	static uint64_t audio_present_history = 0;

firmware/baseband/proc_nfm_audio.hpp

@@ -39,6 +39,16 @@ public:
 	void on_message(const Message* const message) override;
 
 private:
+	std::array<complex16_t, 512> dst;
+	const buffer_c16_t dst_buffer {
+		dst.data(),
+		dst.size()
+	};
+	const buffer_s16_t work_audio_buffer {
+		(int16_t*)dst.data(),
+		sizeof(*dst.data()) * dst.size()
+	};
+
 	dsp::decimate::FIRC8xR16x24FS4Decim8 decim_0;
 	dsp::decimate::FIRC16xR16x32Decim8 decim_1;
 

firmware/baseband/proc_tpms.cpp

@@ -57,12 +57,6 @@ TPMSProcessor::TPMSProcessor() {
 void TPMSProcessor::execute(const buffer_c8_t& buffer) {
 	/* 2.4576MHz, 2048 samples */
 
-	std::array<complex16_t, 512> dst;
-	const buffer_c16_t dst_buffer {
-		dst.data(),
-		dst.size()
-	};
-
 	const auto decim_0_out = decim_0.execute(buffer, dst_buffer);
 	const auto decim_1_out = decim_1.execute(decim_0_out, dst_buffer);
 	const auto decimator_out = decim_1_out;

firmware/baseband/proc_tpms.hpp

@@ -59,6 +59,12 @@ public:
 	void execute(const buffer_c8_t& buffer) override;
 
 private:
+	std::array<complex16_t, 512> dst;
+	const buffer_c16_t dst_buffer {
+		dst.data(),
+		dst.size()
+	};
+
 	dsp::decimate::FIRC8xR16x24FS4Decim4 decim_0;
 	dsp::decimate::FIRC16xR16x16Decim2 decim_1;
 

firmware/baseband/proc_wfm_audio.cpp

@@ -28,21 +28,10 @@ void WidebandFMAudio::execute(const buffer_c8_t& buffer) {
 		return;
 	}
 
-	std::array<complex16_t, 512> dst;
-	const buffer_c16_t dst_buffer {
-		dst.data(),
-		dst.size()
-	};
-
 	const auto decim_0_out = decim_0.execute(buffer, dst_buffer);
 	const auto decim_1_out = decim_1.execute(decim_0_out, dst_buffer);
 	const auto decimator_out = decim_1_out;
 
-	const buffer_s16_t work_audio_buffer {
-		(int16_t*)decimator_out.p,
-		sizeof(*decimator_out.p) * decimator_out.count
-	};
-
 	auto channel = decimator_out;
 
 	// TODO: Feed channel_stats post-decimation data?

firmware/baseband/proc_wfm_audio.hpp

@@ -36,6 +36,16 @@ public:
 	void on_message(const Message* const message) override;
 
 private:
+	std::array<complex16_t, 512> dst;
+	const buffer_c16_t dst_buffer {
+		dst.data(),
+		dst.size()
+	};
+	const buffer_s16_t work_audio_buffer {
+		(int16_t*)dst.data(),
+		sizeof(dst) / sizeof(int16_t)
+	};
+
 	dsp::decimate::FIRC8xR16x24FS4Decim4 decim_0;
 	dsp::decimate::FIRC16xR16x16Decim2 decim_1;