From 474f1343f795df68fa83f932886db302667f7ae5 Mon Sep 17 00:00:00 2001
From: hrydgard <hrydgard@gmail.com>
Date: Fri, 1 May 2009 22:17:22 +0000
Subject: [PATCH] DSPLLE: Wrapping behaviour for single increments/decrements
 of address registers implemented. It made little/no difference as far as I
 can tell :P

git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@3129 8ced0084-cf51-0410-be5f-012b33b47a6e
---
 Source/Core/DSPCore/Src/DSPInterpreter.cpp    | 37 +++++++----------
 Source/Core/DSPCore/Src/gdsp_ext_op.cpp       | 41 ++++++++-----------
 Source/Core/DSPCore/Src/gdsp_interpreter.cpp  | 27 ++++++------
 Source/Core/DSPCore/Src/gdsp_interpreter.h    | 13 +++---
 Source/Core/DSPCore/Src/gdsp_opcodes_helper.h | 33 +++++++++++++++
 Source/Plugins/Plugin_DSP_LLE/Src/main.cpp    | 12 +++---
 6 files changed, 90 insertions(+), 73 deletions(-)

diff --git a/Source/Core/DSPCore/Src/DSPInterpreter.cpp b/Source/Core/DSPCore/Src/DSPInterpreter.cpp
index 9c1c2640c1..a5ec0505c4 100644
--- a/Source/Core/DSPCore/Src/DSPInterpreter.cpp
+++ b/Source/Core/DSPCore/Src/DSPInterpreter.cpp
@@ -166,6 +166,8 @@ void halt(const UDSPInstruction& opc)
 // from register $R reaches zero. Each execution decrement counter. Register
 // $R remains unchanged. If register $R is set to zero at the beginning of loop
 // then looped instruction will not get executed.
+// Actually, this instruction simply prepares the loop stacks for the above.
+// The looping hardware takes care of the rest.
 void loop(const UDSPInstruction& opc)
 {
 	u16 reg = opc.hex & 0x1f;
@@ -186,6 +188,8 @@ void loop(const UDSPInstruction& opc)
 // immediate value I reaches zero. Each execution decrement counter. If
 // immediate value I is set to zero at the beginning of loop then looped
 // instruction will not get executed.
+// Actually, this instruction simply prepares the loop stacks for the above.
+// The looping hardware takes care of the rest.
 void loopi(const UDSPInstruction& opc)
 {
 	u16 cnt = opc.hex & 0xff;
@@ -295,7 +299,7 @@ void lrrd(const UDSPInstruction& opc)
 
 	u16 val = dsp_dmem_read(g_dsp.r[sreg]);
 	dsp_op_write_reg(dreg, val);
-	g_dsp.r[sreg]--;
+	dsp_decrement_addr_reg(sreg);
 }
 
 // LRRI $D, @$S
@@ -310,8 +314,7 @@ void lrri(const UDSPInstruction& opc)
 
 	u16 val = dsp_dmem_read(g_dsp.r[sreg]); 
 	dsp_op_write_reg(dreg, val);
-	g_dsp.r[sreg]++;
-
+	dsp_increment_addr_reg(sreg);
 }
 
 // LRRN $D, @$S
@@ -326,7 +329,7 @@ void lrrn(const UDSPInstruction& opc)
 
 	u16 val = dsp_dmem_read(g_dsp.r[sreg]);
 	dsp_op_write_reg(dreg, val);
-	g_dsp.r[sreg] += g_dsp.r[sreg + 4];
+	g_dsp.r[sreg] += g_dsp.r[DSP_REG_IX0 + sreg];
 }
 
 // SRR @$D, $S
@@ -355,7 +358,7 @@ void srrd(const UDSPInstruction& opc)
 
 	u16 val = dsp_op_read_reg(sreg);
 	dsp_dmem_write(g_dsp.r[dreg], val);
-	g_dsp.r[dreg]--;
+	dsp_decrement_addr_reg(dreg);
 }
 
 // SRRI @$D, $S
@@ -370,7 +373,7 @@ void srri(const UDSPInstruction& opc)
 
 	u16 val = dsp_op_read_reg(sreg);
 	dsp_dmem_write(g_dsp.r[dreg], val);
-	g_dsp.r[dreg]++;
+	dsp_increment_addr_reg(dreg);
 }
 
 // SRRN @$D, $S
@@ -411,7 +414,7 @@ void ilrrd(const UDSPInstruction& opc)
 
 	g_dsp.r[dreg] = dsp_imem_read(g_dsp.r[reg]);
 
-	g_dsp.r[reg]--;
+	dsp_decrement_addr_reg(reg);
 }
 
 // ILRRI $acD.m, @$S
@@ -425,7 +428,7 @@ void ilrri(const UDSPInstruction& opc)
 
 	g_dsp.r[dreg] = dsp_imem_read(g_dsp.r[reg]);
 
-	g_dsp.r[reg]++;
+	dsp_increment_addr_reg(reg);
 }
 
 // ILRRN $acD.m, @$arS
@@ -1385,30 +1388,20 @@ void asr(const UDSPInstruction& opc)
 }
 
 //-------------------------------------------------------------
-
-// hcs give me this code!!
-// DAR $arD
+// DAR $arD  ?
 // 0000 0000 0000 01dd
 // Decrement address register $arD.
-// More docs needed - the operation is really odd!
 void dar(const UDSPInstruction& opc)
 {
-	int reg = opc.hex & 0x3;
-
-	g_dsp.r[reg]--;   // TODO: Wrap properly.
+	dsp_decrement_addr_reg(opc.hex & 0x3);
 }
 
-
-// hcs give me this code!!
-// IAR $arD
+// IAR $arD  ?
 // 0000 0000 0000 10dd
 // Increment address register $arD.
-// More docs needed - the operation is really odd!
 void iar(const UDSPInstruction& opc)
 {
-	int reg = opc.hex & 0x3;
-
-	g_dsp.r[reg]++;   // TODO: Wrap properly according to the corresponding WR register.
+	dsp_increment_addr_reg(opc.hex & 0x3);
 }
 
 //-------------------------------------------------------------
diff --git a/Source/Core/DSPCore/Src/gdsp_ext_op.cpp b/Source/Core/DSPCore/Src/gdsp_ext_op.cpp
index 4d0bde0ed2..e352899839 100644
--- a/Source/Core/DSPCore/Src/gdsp_ext_op.cpp
+++ b/Source/Core/DSPCore/Src/gdsp_ext_op.cpp
@@ -50,18 +50,14 @@ namespace Ext
 // xxxx xxxx 0000 01rr
 // Decrement addressing register $arR.
 void dr(const UDSPInstruction& opc) {
-	u8 reg = opc.hex & 0x3;	
-	
-	g_dsp.r[reg]--;
+	dsp_decrement_addr_reg(opc.hex & 0x3);
 }
 
 // IR $arR
 // xxxx xxxx 0000 10rr
 // Increment addressing register $arR.
 void ir(const UDSPInstruction& opc) {
-	u8 reg = opc.hex & 0x3;	
-	
-	g_dsp.r[reg]++;
+	dsp_increment_addr_reg(opc.hex & 0x3);
 }
 
 // NR $arR
@@ -95,7 +91,7 @@ void s(const UDSPInstruction& opc)
 
 	dsp_dmem_write(g_dsp.r[dreg], g_dsp.r[sreg]);
 
-	g_dsp.r[dreg]++;
+	dsp_increment_addr_reg(dreg);
 }
 
 // SN @$D, $acD.l
@@ -124,7 +120,7 @@ void l(const UDSPInstruction& opc)
 	u16 val = dsp_dmem_read(g_dsp.r[sreg]);
 	g_dsp.r[dreg] = val;
 
-	g_dsp.r[sreg]++;
+	dsp_increment_addr_reg(sreg);
 }
 
 // LN axD.l, @$S
@@ -153,8 +149,8 @@ void ld(const UDSPInstruction& opc)
 	g_dsp.r[dreg] = dsp_dmem_read(g_dsp.r[sreg]);
 	g_dsp.r[rreg] = dsp_dmem_read(g_dsp.r[DSP_REG_AR3]);
 
-	g_dsp.r[sreg]++;
-	g_dsp.r[DSP_REG_AR3]++;
+	dsp_increment_addr_reg(sreg);
+	dsp_increment_addr_reg(DSP_REG_AR3);
 }
 
 // Not in duddie's doc
@@ -169,7 +165,7 @@ void ldn(const UDSPInstruction& opc)
 	g_dsp.r[rreg] = dsp_dmem_read(g_dsp.r[DSP_REG_AR3]);
 
 	g_dsp.r[sreg] += g_dsp.r[sreg + DSP_REG_IX0];
-	g_dsp.r[DSP_REG_AR3]++;
+	dsp_increment_addr_reg(DSP_REG_AR3);
 }
 
 // Not in duddie's doc
@@ -183,7 +179,7 @@ void ldm(const UDSPInstruction& opc)
 	g_dsp.r[dreg] = dsp_dmem_read(g_dsp.r[sreg]);
 	g_dsp.r[rreg] = dsp_dmem_read(g_dsp.r[DSP_REG_AR3]);
 
-	g_dsp.r[sreg]++;
+	dsp_increment_addr_reg(sreg);
 	g_dsp.r[DSP_REG_AR3] += g_dsp.r[DSP_REG_IX3];
 }
 
@@ -215,11 +211,11 @@ void dsp_op_ext_r_epi(const UDSPInstruction& opc)
 		break;
 		
 	case 0x01: // DR
-		g_dsp.r[reg]--;
+		dsp_decrement_addr_reg(reg);
 		break;
 		
 	case 0x02: // IR
-		g_dsp.r[reg]++;
+		dsp_increment_addr_reg(reg);
 		break;
 		
 	  case 0x03: // NR
@@ -251,7 +247,7 @@ void dsp_op_ext_s(const UDSPInstruction& opc)
 	}
 	else
 	{
-		g_dsp.r[dreg]++; // S
+		dsp_increment_addr_reg(dreg); // S
 	}
 }
 
@@ -270,7 +266,7 @@ void dsp_op_ext_l(const UDSPInstruction& opc)
 	}
 	else
 	{
-		g_dsp.r[sreg]++; // LS
+		dsp_increment_addr_reg(sreg); // LS
 	}
 }
 
@@ -286,7 +282,7 @@ void dsp_op_ext_ls_pro(const UDSPInstruction& opc)
 	} 
 	else // LS
 	{
-		g_dsp.r[0x03]++;
+		dsp_increment_addr_reg(0x03);
 	}
 }
 
@@ -303,7 +299,7 @@ void dsp_op_ext_ls_epi(const UDSPInstruction& opc)
 	}
 	else // LS
 	{
-		g_dsp.r[0x00]++; 
+		dsp_increment_addr_reg(0x00); 
 	}
 }
 
@@ -319,7 +315,7 @@ void dsp_op_ext_sl_pro(const UDSPInstruction& opc)
 	}
 	else // SL 
 	{
-		g_dsp.r[0x00]++;
+		dsp_increment_addr_reg(0x00);
 	}
 }
 
@@ -336,7 +332,7 @@ void dsp_op_ext_sl_epi(const UDSPInstruction& opc)
 	}
 	else // SL
 	{
-		g_dsp.r[0x03]++;
+		dsp_increment_addr_reg(0x03);
 	}
 }
 
@@ -355,7 +351,7 @@ void dsp_op_ext_ld(const UDSPInstruction& opc)
 	}
 	else
 	{
-		g_dsp.r[sreg]++;
+		dsp_increment_addr_reg(sreg);
 	}
 	
 	if (opc.hex & 0x08) // M
@@ -364,9 +360,8 @@ void dsp_op_ext_ld(const UDSPInstruction& opc)
 	}
 	else
 	{
-		g_dsp.r[0x03]++;
+		dsp_increment_addr_reg(0x03);
 	}
-	
 }
 
 
diff --git a/Source/Core/DSPCore/Src/gdsp_interpreter.cpp b/Source/Core/DSPCore/Src/gdsp_interpreter.cpp
index ea816486dc..883e6e8881 100644
--- a/Source/Core/DSPCore/Src/gdsp_interpreter.cpp
+++ b/Source/Core/DSPCore/Src/gdsp_interpreter.cpp
@@ -38,10 +38,9 @@ namespace DSPInterpreter {
 
 volatile u32 gdsp_running;
 
-
 // Hm, should instructions that change CR use this? Probably not (but they
 // should call UpdateCachedCR())
-void gdsp_write_cr(u16 val)
+void WriteCR(u16 val)
 {
 	// reset
 	if (val & 0x0001)
@@ -55,9 +54,8 @@ void gdsp_write_cr(u16 val)
 	g_dsp.cr = val;
 }
 
-
 // Hm, should instructions that read CR use this? (Probably not).
-u16 gdsp_read_cr()
+u16 ReadCR()
 {
 	if (g_dsp.pc & 0x8000)
 	{
@@ -71,8 +69,7 @@ u16 gdsp_read_cr()
 	return g_dsp.cr;
 }
 
-
-void gdsp_handle_loop()
+void HandleLoop()
 {
 	// Handle looping hardware. 
 	u16& rLoopCounter = g_dsp.r[DSP_REG_ST3];
@@ -100,7 +97,7 @@ void gdsp_handle_loop()
 	}
 }
 
-void gdsp_step()
+void Step()
 {
 	gdsp_check_exceptions();
 
@@ -123,11 +120,11 @@ void gdsp_step()
 
 	u16 opc = dsp_fetch_code();
 	ExecuteInstruction(UDSPInstruction(opc));
-	gdsp_handle_loop();
+	HandleLoop();
 }
 
 // Used by thread mode.
-void gdsp_run()
+void Run()
 {
 	gdsp_running = true;
 	while (!(g_dsp.cr & CR_HALT))
@@ -139,7 +136,7 @@ void gdsp_run()
 		gdsp_check_external_int();
 		// This number (500) is completely arbitrary. TODO: tweak.
 		for (int i = 0; i < 500 && !(g_dsp.cr & CR_HALT); i++)
-			gdsp_step();
+			Step();
 
 		if (!gdsp_running)
 			break;
@@ -148,7 +145,7 @@ void gdsp_run()
 }
 
 // Used by non-thread mode.
-void gdsp_run_cycles(int cycles)
+void RunCycles(int cycles)
 {
 	gdsp_check_external_int();
 
@@ -157,7 +154,7 @@ void gdsp_run_cycles(int cycles)
 	{
 		if (g_dsp.cr & CR_HALT)
 			return;
-		gdsp_step();
+		Step();
 		cycles--;
 	}
 
@@ -168,7 +165,7 @@ void gdsp_run_cycles(int cycles)
 			return;
 		if (DSPAnalyzer::code_flags[g_dsp.pc] & DSPAnalyzer::CODE_IDLE_SKIP)
 			return;
-		gdsp_step();
+		Step();
 		cycles--;
 	}
 
@@ -176,14 +173,14 @@ void gdsp_run_cycles(int cycles)
 	// idle loop and if so we waste some time here. Might be beneficial to slice even further.
 	while (cycles > 0)
 	{
-		gdsp_step();
+		Step();
 		cycles--;
 		// We don't bother directly supporting pause - if the main emu pauses,
 		// it just won't call this function anymore.
 	}
 }
 
-void gdsp_stop()
+void Stop()
 {
 	gdsp_running = false;
 }
diff --git a/Source/Core/DSPCore/Src/gdsp_interpreter.h b/Source/Core/DSPCore/Src/gdsp_interpreter.h
index 06869b4004..f8504f72ce 100644
--- a/Source/Core/DSPCore/Src/gdsp_interpreter.h
+++ b/Source/Core/DSPCore/Src/gdsp_interpreter.h
@@ -48,14 +48,13 @@
 namespace DSPInterpreter {
 
 // steps through DSP code, returns false if error occured
-void gdsp_step();
-void gdsp_loop_step();
-void gdsp_run();
-void gdsp_run_cycles(int cycles);
-void gdsp_stop();
+void Step();
+void Run();
+void RunCycles(int cycles);
+void Stop();
 
-void gdsp_write_cr(u16 val);
-u16  gdsp_read_cr();
+void WriteCR(u16 val);
+u16  ReadCR();
 
 }  // namespace
 
diff --git a/Source/Core/DSPCore/Src/gdsp_opcodes_helper.h b/Source/Core/DSPCore/Src/gdsp_opcodes_helper.h
index a53902be17..2a071bb563 100644
--- a/Source/Core/DSPCore/Src/gdsp_opcodes_helper.h
+++ b/Source/Core/DSPCore/Src/gdsp_opcodes_helper.h
@@ -50,6 +50,39 @@ inline bool dsp_SR_is_flag_set(int flag)
 	return (g_dsp.r[DSP_REG_SR] & (1 << flag)) != 0;
 }
 
+
+// See http://code.google.com/p/dolphin-emu/source/detail?r=3125
+inline void dsp_decrement_addr_reg(int reg)
+{
+	// This one was easy. increment is worse...
+	if ((g_dsp.r[reg] & g_dsp.r[DSP_REG_WR0 + reg]) == 0)
+		g_dsp.r[reg] |= g_dsp.r[DSP_REG_WR0 + reg];
+	else
+		g_dsp.r[reg]--;
+}
+
+
+// HORRIBLE UGLINESS, someone please fix.
+// See http://code.google.com/p/dolphin-emu/source/detail?r=3125
+
+inline u16 ToMask(u16 a)
+{
+	a = a | (a >> 8);
+	a = a | (a >> 4);
+	a = a | (a >> 2);
+	return a | (a >> 1);
+}
+
+inline void dsp_increment_addr_reg(int reg)
+{
+	u16 tmb = ToMask(g_dsp.r[DSP_REG_WR0 + reg]);
+	if ((g_dsp.r[reg] & tmb) == tmb)
+		g_dsp.r[reg] ^= g_dsp.r[DSP_REG_WR0 + reg];
+	else
+		g_dsp.r[reg]++;
+}
+
+
 // ---------------------------------------------------------------------------------------
 // --- reg
 // ---------------------------------------------------------------------------------------
diff --git a/Source/Plugins/Plugin_DSP_LLE/Src/main.cpp b/Source/Plugins/Plugin_DSP_LLE/Src/main.cpp
index e7de70632e..51427f3158 100644
--- a/Source/Plugins/Plugin_DSP_LLE/Src/main.cpp
+++ b/Source/Plugins/Plugin_DSP_LLE/Src/main.cpp
@@ -179,7 +179,7 @@ THREAD_RETURN dsp_thread(void* lpParameter)
 {
 	while (bIsRunning)
 	{
-		DSPInterpreter::gdsp_run();
+		DSPInterpreter::Run();
 	}
 	return 0;
 }
@@ -249,7 +249,7 @@ void Initialize(void *init)
 
 void DSP_StopSoundStream()
 {
-	DSPInterpreter::gdsp_stop();
+	DSPInterpreter::Stop();
 	bIsRunning = false;
 	if (g_dspInitialize.bOnThread)
 	{
@@ -266,13 +266,13 @@ void Shutdown()
 
 u16 DSP_WriteControlRegister(u16 _uFlag)
 {
-	DSPInterpreter::gdsp_write_cr(_uFlag);
-	return DSPInterpreter::gdsp_read_cr();
+	DSPInterpreter::WriteCR(_uFlag);
+	return DSPInterpreter::ReadCR();
 }
 
 u16 DSP_ReadControlRegister()
 {
-	return DSPInterpreter::gdsp_read_cr();
+	return DSPInterpreter::ReadCR();
 }
 
 u16 DSP_ReadMailboxHigh(bool _CPUMailbox)
@@ -343,7 +343,7 @@ void DSP_Update(int cycles)
 	// If we're not on a thread, run cycles here.
 	if (!g_dspInitialize.bOnThread)
 	{
-		DSPInterpreter::gdsp_run_cycles(cycles);
+		DSPInterpreter::RunCycles(cycles);
 	}
 }