From c5f47a8db30cfc006e5c9864540623a54c3237dc Mon Sep 17 00:00:00 2001
From: Ziemas <ziemas@ziemas.se>
Date: Sat, 8 Jul 2023 18:58:06 +0200
Subject: [PATCH] mipsanalyst: sign extend 32 bit regs

---
 pcsx2/DebugTools/MIPSAnalyst.cpp | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/pcsx2/DebugTools/MIPSAnalyst.cpp b/pcsx2/DebugTools/MIPSAnalyst.cpp
index f6c971d603..84503591bf 100644
--- a/pcsx2/DebugTools/MIPSAnalyst.cpp
+++ b/pcsx2/DebugTools/MIPSAnalyst.cpp
@@ -342,7 +342,7 @@ namespace MIPSAnalyst
 			info.isLinkedBranch = (opcode.flags & IS_LINKED) != 0;
 			info.isLikelyBranch = (opcode.flags & IS_LIKELY) != 0;
 
-			u64 rs,rt;
+			s64 rs,rt;
 			u32 value;
 			switch (opcode.flags & BRANCHTYPE_MASK)
 			{
@@ -354,8 +354,15 @@ namespace MIPSAnalyst
 				info.isConditional = true;
 				info.branchTarget = info.opcodeAddress + 4 + ((s16)(op&0xFFFF)<<2);
 
-				rs = info.cpu->getRegister(0,MIPS_GET_RS(op))._u64[0];
-				rt = info.cpu->getRegister(0,MIPS_GET_RT(op))._u64[0];
+				// Sign extend from 32bit for IOP regs
+				if (info.cpu->getRegisterSize(0) == 32) {
+					rs = (s32)info.cpu->getRegister(0,MIPS_GET_RS(op))._u32[0];
+					rt = (s32)info.cpu->getRegister(0,MIPS_GET_RT(op))._u32[0];
+				} else {
+					rs = (s64)info.cpu->getRegister(0,MIPS_GET_RS(op))._u64[0];
+					rt = (s64)info.cpu->getRegister(0,MIPS_GET_RT(op))._u64[0];
+				}
+
 				switch (opcode.flags & CONDTYPE_MASK)
 				{
 				case CONDTYPE_EQ:
@@ -369,16 +376,16 @@ namespace MIPSAnalyst
 						info.isConditional = false;
 					break;
 				case CONDTYPE_LEZ:
-					info.conditionMet = (((s64)rs) <= 0);
+					info.conditionMet = (rs <= 0);
 					break;
 				case CONDTYPE_GTZ:
-					info.conditionMet = (((s64)rs) > 0);
+					info.conditionMet = (rs > 0);
 					break;
 				case CONDTYPE_LTZ:
-					info.conditionMet = (((s64)rs) < 0);
+					info.conditionMet = (rs < 0);
 					break;
 				case CONDTYPE_GEZ:
-					info.conditionMet = (((s64)rs) >= 0);
+					info.conditionMet = (rs >= 0);
 					break;
 				}