From 161edbf2f6e5691352bbd775cf6524ba85376314 Mon Sep 17 00:00:00 2001
From: Megamouse <studienricky89@googlemail.com>
Date: Wed, 7 Aug 2024 23:18:32 +0200
Subject: [PATCH] cellMic: make bit_resolution and channel_size constexpr

This allows us to optimize and inline variable_byteswap
---
 rpcs3/Emu/Cell/Modules/cellMic.cpp | 21 ++++++++++++++-------
 rpcs3/Emu/Cell/Modules/cellMic.h   |  7 ++++---
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/rpcs3/Emu/Cell/Modules/cellMic.cpp b/rpcs3/Emu/Cell/Modules/cellMic.cpp
index 03f0d4c994..946c34633a 100644
--- a/rpcs3/Emu/Cell/Modules/cellMic.cpp
+++ b/rpcs3/Emu/Cell/Modules/cellMic.cpp
@@ -241,13 +241,20 @@ bool mic_context::check_device(u32 dev_num)
 
 // Static functions
 
-void microphone_device::variable_byteswap(const void* src, void* dst, const u32 bytesize)
+template <u32 bytesize>
+inline void microphone_device::variable_byteswap(const void* src, void* dst)
 {
-	switch (bytesize)
+	if constexpr (bytesize == 4)
 	{
-	case 4: *static_cast<u32*>(dst) = *static_cast<const be_t<u32>*>(src); break;
-	case 2: *static_cast<u16*>(dst) = *static_cast<const be_t<u16>*>(src); break;
-	default: break;
+		*static_cast<u32*>(dst) = *static_cast<const be_t<u32>*>(src);
+	}
+	else if constexpr (bytesize == 2)
+	{
+		*static_cast<u16*>(dst) = *static_cast<const be_t<u16>*>(src);
+	}
+	else
+	{
+		fmt::throw_exception("variable_byteswap with bytesize %d unimplemented", bytesize);
 	}
 }
 
@@ -588,7 +595,7 @@ void microphone_device::get_data(const u32 num_samples)
 	case microphone_handler::standard:
 	case microphone_handler::rocksmith:
 	{
-		const u8 channel_size = bit_resolution / 8;
+		constexpr u8 channel_size = bit_resolution / 8;
 		const usz bufsize = num_samples * sample_size;
 		const std::vector<u8>& buf = ::at32(devices, 0).buf;
 		ensure(bufsize <= buf.size());
@@ -602,7 +609,7 @@ void microphone_device::get_data(const u32 num_samples)
 			for (u32 indchan = 0; indchan < num_channels; indchan++)
 			{
 				const u32 curindex = sample_pos + indchan * channel_size;
-				microphone_device::variable_byteswap(buf.data() + curindex, tmp_ptr + curindex, channel_size);
+				microphone_device::variable_byteswap<channel_size>(buf.data() + curindex, tmp_ptr + curindex);
 			}
 		}
 		break;
diff --git a/rpcs3/Emu/Cell/Modules/cellMic.h b/rpcs3/Emu/Cell/Modules/cellMic.h
index aec7dd49b3..b1d4982523 100644
--- a/rpcs3/Emu/Cell/Modules/cellMic.h
+++ b/rpcs3/Emu/Cell/Modules/cellMic.h
@@ -294,7 +294,7 @@ public:
 	bool is_opened() const { return mic_opened; }
 	bool is_started() const { return mic_started; }
 	u8 get_signal_types() const { return signal_types; }
-	u8 get_bit_resolution() const {	return bit_resolution; }
+	constexpr u8 get_bit_resolution() const { return bit_resolution; }
 	u32 get_raw_samplingrate() const { return raw_samplingrate; }
 	u8 get_num_channels() const { return num_channels; }
 	u8 get_datatype() const
@@ -321,7 +321,8 @@ public:
 	u32 attr_dsptype    = 0;
 
 private:
-	static void variable_byteswap(const void* src, void* dst, const u32 bytesize);
+	template <u32 bytesize>
+	static inline void variable_byteswap(const void* src, void* dst);
 
 	u32 capture_audio();
 
@@ -349,13 +350,13 @@ private:
 	u32 raw_samplingrate = 48000;
 	u32 dsp_samplingrate = 48000;
 	u32 aux_samplingrate = 48000;
-	u8 bit_resolution    = 16;
 	u8 num_channels      = 2;
 
 	u8 signal_types = CELLMIC_SIGTYPE_NULL;
 
 	u32 sample_size = 0; // Determined at opening for internal use
 
+	static constexpr u8 bit_resolution = 16;
 	static constexpr usz inbuf_size = 400000; // Default value unknown
 
 	simple_ringbuf<inbuf_size> rbuf_raw;