From 767756cfb48ca46ba9a5656759e78fda4dafa15f Mon Sep 17 00:00:00 2001
From: unknown <rj150@hotmail.com>
Date: Sun, 21 Jun 2015 15:52:30 -0400
Subject: [PATCH] centered standard MIPS PC-relative branch stuff to its own
 func

---
 Source/RSP/Interpreter CPU.c | 15 +++++++++++
 Source/RSP/Interpreter CPU.h |  6 +++++
 Source/RSP/Interpreter Ops.c | 48 ++++++------------------------------
 3 files changed, 29 insertions(+), 40 deletions(-)

diff --git a/Source/RSP/Interpreter CPU.c b/Source/RSP/Interpreter CPU.c
index 0849ef90d..2a7d00365 100644
--- a/Source/RSP/Interpreter CPU.c	
+++ b/Source/RSP/Interpreter CPU.c	
@@ -472,3 +472,18 @@ DWORD RunInterpreterCPU(DWORD Cycles) {
 	return Cycles;
 }
 
+unsigned int RSP_branch_if(int condition)
+{
+    unsigned int new_PC;
+
+ /* RSP_NextInstruction = DELAY_SLOT; */
+    if (condition)
+    {
+        new_PC = *PrgCount + 4 + ((short)RSPOpC.offset << 2);
+    }
+    else
+    {
+        new_PC = *PrgCount + 4 + 4;
+    }
+    return (new_PC & 0xFFC);
+}
diff --git a/Source/RSP/Interpreter CPU.h b/Source/RSP/Interpreter CPU.h
index 861319ba3..17c33ec3a 100644
--- a/Source/RSP/Interpreter CPU.h	
+++ b/Source/RSP/Interpreter CPU.h	
@@ -38,5 +38,11 @@
 
 extern DWORD RSP_NextInstruction, RSP_JumpTo, RSP_MfStatusCount;
 
+/*
+ * standard MIPS PC-relative branch
+ * returns the new PC, based on whether the condition passes
+ */
+unsigned int RSP_branch_if(int condition);
+
 void BuildInterpreterCPU(void);
 DWORD RunInterpreterCPU(DWORD Cycles);
diff --git a/Source/RSP/Interpreter Ops.c b/Source/RSP/Interpreter Ops.c
index eb8f2f5b3..e5706b8ae 100644
--- a/Source/RSP/Interpreter Ops.c	
+++ b/Source/RSP/Interpreter Ops.c	
@@ -63,38 +63,22 @@ void RSP_Opcode_JAL ( void ) {
 
 void RSP_Opcode_BEQ ( void ) {
 	RSP_NextInstruction = DELAY_SLOT;
-	if (RSP_GPR[RSPOpC.rs].W == RSP_GPR[RSPOpC.rt].W) {
-		RSP_JumpTo = ( *PrgCount + ((short)RSPOpC.offset << 2) + 4 ) & 0xFFC;
-	} else  {
-		RSP_JumpTo = ( *PrgCount + 8 ) & 0xFFC;
-	}
+	RSP_JumpTo = RSP_branch_if(RSP_GPR[RSPOpC.rs].W == RSP_GPR[RSPOpC.rt].W);
 }
 
 void RSP_Opcode_BNE ( void ) {
 	RSP_NextInstruction = DELAY_SLOT;
-	if (RSP_GPR[RSPOpC.rs].W != RSP_GPR[RSPOpC.rt].W) {
-		RSP_JumpTo = ( *PrgCount + ((short)RSPOpC.offset << 2) + 4 ) & 0xFFC;
-	} else  {
-		RSP_JumpTo = ( *PrgCount + 8 ) & 0xFFC;
-	}
+	RSP_JumpTo = RSP_branch_if(RSP_GPR[RSPOpC.rs].W != RSP_GPR[RSPOpC.rt].W);
 }
 
 void RSP_Opcode_BLEZ ( void ) {
 	RSP_NextInstruction = DELAY_SLOT;
-	if (RSP_GPR[RSPOpC.rs].W <= 0) {
-		RSP_JumpTo = ( *PrgCount + ((short)RSPOpC.offset << 2) + 4 ) & 0xFFC;
-	} else  {
-		RSP_JumpTo = ( *PrgCount + 8 ) & 0xFFC;
-	}
+	RSP_JumpTo = RSP_branch_if(RSP_GPR[RSPOpC.rs].W <= 0);
 }
 
 void RSP_Opcode_BGTZ ( void ) {
 	RSP_NextInstruction = DELAY_SLOT;
-	if (RSP_GPR[RSPOpC.rs].W > 0) {
-		RSP_JumpTo = ( *PrgCount + ((short)RSPOpC.offset << 2) + 4 ) & 0xFFC;
-	} else  {
-		RSP_JumpTo = ( *PrgCount + 8 ) & 0xFFC;
-	}
+	RSP_JumpTo = RSP_branch_if(RSP_GPR[RSPOpC.rs].W >  0);
 }
 
 void RSP_Opcode_ADDI ( void ) {
@@ -293,40 +277,24 @@ void RSP_Special_SLTU (void) {
 /********************** R4300i OpCodes: RegImm **********************/
 void RSP_Opcode_BLTZ ( void ) {
 	RSP_NextInstruction = DELAY_SLOT;
-	if (RSP_GPR[RSPOpC.rs].W < 0) {
-		RSP_JumpTo = ( *PrgCount + ((short)RSPOpC.offset << 2) + 4 ) & 0xFFC;
-	} else  {
-		RSP_JumpTo = ( *PrgCount + 8 ) & 0xFFC;
-	}
+	RSP_JumpTo = RSP_branch_if(RSP_GPR[RSPOpC.rs].W <  0);
 }
 
 void RSP_Opcode_BGEZ ( void ) {
 	RSP_NextInstruction = DELAY_SLOT;
-	if (RSP_GPR[RSPOpC.rs].W >= 0) {
-		RSP_JumpTo = ( *PrgCount + ((short)RSPOpC.offset << 2) + 4 ) & 0xFFC;
-	} else  {
-		RSP_JumpTo = ( *PrgCount + 8 ) & 0xFFC;
-	}
+	RSP_JumpTo = RSP_branch_if(RSP_GPR[RSPOpC.rs].W >= 0);
 }
 
 void RSP_Opcode_BLTZAL ( void ) {
 	RSP_NextInstruction = DELAY_SLOT;
 	RSP_GPR[31].UW = ( *PrgCount + 8 ) & 0xFFC;
-	if (RSP_GPR[RSPOpC.rs].W < 0) {
-		RSP_JumpTo = ( *PrgCount + ((short)RSPOpC.offset << 2) + 4 ) & 0xFFC;
-	} else  {
-		RSP_JumpTo = ( *PrgCount + 8 ) & 0xFFC;
-	}
+	RSP_JumpTo = RSP_branch_if(RSP_GPR[RSPOpC.rs].W <  0);
 }
 
 void RSP_Opcode_BGEZAL ( void ) {
 	RSP_NextInstruction = DELAY_SLOT;
 	RSP_GPR[31].UW = ( *PrgCount + 8 ) & 0xFFC;
-	if (RSP_GPR[RSPOpC.rs].W >= 0) {
-		RSP_JumpTo = ( *PrgCount + ((short)RSPOpC.offset << 2) + 4 ) & 0xFFC;
-	} else  {
-		RSP_JumpTo = ( *PrgCount + 8 ) & 0xFFC;
-	}
+	RSP_JumpTo = RSP_branch_if(RSP_GPR[RSPOpC.rs].W >= 0);
 }
 
 /************************** Cop0 functions *************************/