Rollback on a DSI exception, for the instructions that need it.

Not a good thing to say, but this isn't properly tested, since I don't know of any game that generates a DSI exception. I'll try to write some homebrew to test this, but I'm pretty confident it's ok. Anyway, please take a look at it and tell me if you find some mistake :-)


git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@6172 8ced0084-cf51-0410-be5f-012b33b47a6e

Source/Core/Core/Src/PowerPC/Interpreter/Interpreter_LoadStore.cpp

@@ -195,39 +195,65 @@ void Interpreter::lhzu(UGeckoInstruction _inst)
 	}
 }
 
-// FIXME: lmw should do a total rollback if a DSI occurs
 void Interpreter::lmw(UGeckoInstruction _inst)
 {
-	u32 uAddress = Helper_Get_EA(_inst);
+	u32 EA = Helper_Get_EA(_inst);
-	for (int iReg = _inst.RD; iReg <= 31; iReg++, uAddress += 4)
+	int r = _inst.RD;
+
+	const int rb_r = r;
+	static u32 rb_GPR[32];
+
+	while (r <= 31)
 	{
-		u32 TempReg = Memory::Read_U32(uAddress);		
+		u32 TempReg = Memory::Read_U32(EA);		
 		if (PowerPC::ppcState.Exceptions & EXCEPTION_DSI)
 		{
 			PanicAlert("DSI exception in lmw");
 			NOTICE_LOG(POWERPC, "DSI exception in lmw");
+
+			while (r > rb_r)
+			{
+				m_GPR[r] = rb_GPR[r];
+				r--;
+			}
 			return;
 		}
-		else
+		rb_GPR[r] = m_GPR[r];
-		{
+		m_GPR[r] = TempReg;
-			m_GPR[iReg] = TempReg;
+
-		}
+		r++;
+		EA += 4;
 	}
 }
 
-// FIXME: stmw should do a total rollback if a DSI occurs
 void Interpreter::stmw(UGeckoInstruction _inst)
 {
-	u32 uAddress = Helper_Get_EA(_inst);
+	u32 EA = Helper_Get_EA(_inst);
-	for (int iReg = _inst.RS; iReg <= 31; iReg++, uAddress+=4)
+	int r = _inst.RS;
-	{		
+
-		Memory::Write_U32(m_GPR[iReg], uAddress);
+	const int rb_r = r;
+	static u32 rb_mem[32];
+
+	while (r <= 31)
+	{
+		rb_mem[r] = Memory::ReadUnchecked_U32(EA);
+		Memory::Write_U32(m_GPR[r], EA);
 		if (PowerPC::ppcState.Exceptions & EXCEPTION_DSI)
 		{
 			PanicAlert("DSI exception in stmw");
 			NOTICE_LOG(POWERPC, "DSI exception in stmw");
+
+			while (r > rb_r)
+			{
+				Memory::WriteUnchecked_U32(rb_mem[r], EA);
+				r--;
+				EA -= 4;
+			}
 			return;
 		}
+
+		r++;
+		EA += 4;
 	}
 }
 
@@ -523,7 +549,6 @@ void Interpreter::lhzx(UGeckoInstruction _inst)
 }
 
 // TODO: is this right?
-// FIXME: Should rollback if a DSI occurs
 void Interpreter::lswx(UGeckoInstruction _inst)
 {
 	u32 EA = Helper_Get_EA_X(_inst);
@@ -531,8 +556,13 @@ void Interpreter::lswx(UGeckoInstruction _inst)
 	int r = _inst.RD;
 	int i = 0;
 
+	const u32 rb_EA = EA;
+	const int rb_r = r;
+	static u32 rb_GPR[32];
+
 	if (n > 0)
 	{
+		rb_GPR[r] = m_GPR[r];
 		m_GPR[r] = 0;
 		do
 		{
@@ -541,6 +571,17 @@ void Interpreter::lswx(UGeckoInstruction _inst)
 			{
 				PanicAlert("DSI exception in lswx.");
 				NOTICE_LOG(POWERPC, "DSI exception in lswx");
+
+				n = ((EA - rb_EA) / 4) + 1;
+				EA = rb_EA;
+				r = rb_r;
+				while (n > 0)
+				{
+					m_GPR[r] = rb_GPR[r];
+					r = (r + 1) & 31;
+					EA += 4;
+					n--;
+				}
 				return;
 			}
 			m_GPR[r] |= TempValue;
@@ -552,6 +593,7 @@ void Interpreter::lswx(UGeckoInstruction _inst)
 			{
 				i = 0;
 				r = (r + 1) & 31;
+				rb_GPR[r] = m_GPR[r];
 				m_GPR[r] = 0;
 			}
 		} while (n > 0);
@@ -667,7 +709,6 @@ void Interpreter::sthx(UGeckoInstruction _inst)
 
 // __________________________________________________________________________________________________
 // lswi - bizarro string instruction
-// FIXME: Should rollback if a DSI occurs
 void Interpreter::lswi(UGeckoInstruction _inst)
 {
 	u32 EA;
@@ -682,38 +723,55 @@ void Interpreter::lswi(UGeckoInstruction _inst)
 	else
 		n = _inst.NB;
 
-	int r = _inst.RD - 1;
+	int r = _inst.RD;
 	int i = 0;
-	while (n>0)
+
+	const u32 rb_EA = EA;
+	const int rb_r = r;
+	static u32 rb_GPR[32];
+
+	if (n > 0)
 	{
-		if (i==0)
+		rb_GPR[r] = m_GPR[r];
+		m_GPR[r] = 0;
+		do
 		{
-			r++;
+			u32 TempValue = Memory::Read_U8(EA) << (24 - i);
-			r &= 31;
+			if (PowerPC::ppcState.Exceptions & EXCEPTION_DSI)
-			m_GPR[r] = 0;
+			{
-		}
+				PanicAlert("DSI exception in lswi.");
 
-		u32 TempValue = Memory::Read_U8(EA) << (24 - i);		
+				n = ((EA - rb_EA) / 4) + 1;
-		if (PowerPC::ppcState.Exceptions & EXCEPTION_DSI)
+				EA = rb_EA;
-		{
+				r = rb_r;
-			PanicAlert("DSI exception in lsw.");
+				while (n > 0)
-			return;
+				{
-		}
+					m_GPR[r] = rb_GPR[r];
+					r = (r + 1) & 31;
+					EA += 4;
+					n--;
+				}
+				return;
+			}
+			m_GPR[r] |= TempValue;
 
-		m_GPR[r] |= TempValue;
+			EA++;
-
+			n--;
-		i += 8;
+			i += 8;
-		if (i == 32)
+			if (i == 32)
-			i = 0;
+			{
-		EA++;
+				i = 0;
-		n--;
+				r = (r + 1) & 31;
+				rb_GPR[r] = m_GPR[r];
+				m_GPR[r] = 0;
+			}
+		} while (n > 0);
 	}
 }
 
 // todo : optimize ?
 // __________________________________________________________________________________________________
 // stswi - bizarro string instruction
-// FIXME: Should rollback if a DSI occurs
 void Interpreter::stswi(UGeckoInstruction _inst)
 {
 	u32 EA;
@@ -728,26 +786,47 @@ void Interpreter::stswi(UGeckoInstruction _inst)
 	else
 		n = _inst.NB;
 
-	int r = _inst.RS - 1;
+	int r = _inst.RS;
 	int i = 0;
-	while (n > 0)
+
-	{
+	const u32 rb_EA = EA;
-		if (i == 0)
+	const int rb_r = r;
-		{
+	static u32 rb_mem[32];
-			r++;
+
-			r &= 31;
+	while (n > 0) {
-		}
+		rb_mem[r] |= Memory::ReadUnchecked_U8(EA) << (24 - i);
 		Memory::Write_U8((m_GPR[r] >> (24 - i)) & 0xFF, EA);
 		if (PowerPC::ppcState.Exceptions & EXCEPTION_DSI)
 		{
+			PanicAlert("DSI exception in stswi.");
+
+			n = EA - rb_EA;
+			EA = rb_EA;
+			r = rb_r;
+			i = 0;
+			while (n > 0)
+			{
+				Memory::WriteUnchecked_U8((rb_mem[r] >> (24 - i)) & 0xFF, EA);
+				EA++;
+				i += 8;
+				if (i == 32)
+				{
+					i = 0;
+					r = (r + 1) & 31;
+				}
+				n--;
+			}
 			return;
 		}
 
-		i += 8;
-		if (i == 32)
-			i = 0;
 		EA++;
 		n--;
+		i += 8;
+		if (i == 32)
+		{
+			i = 0;
+			r = (r + 1) & 31;
+		}
 	}
 }