From b32703333340d85d86d14ac53667b5515e420918 Mon Sep 17 00:00:00 2001
From: refractionpcsx2 <refraction@gmail.com>
Date: Fri, 30 Jun 2023 18:18:47 +0100
Subject: [PATCH] Counters: Process overflow before Target in case of Target =
 0

---
 pcsx2/Counters.cpp    | 12 ++++++++----
 pcsx2/IopCounters.cpp |  6 +++---
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/pcsx2/Counters.cpp b/pcsx2/Counters.cpp
index a25828f307..306c338492 100644
--- a/pcsx2/Counters.cpp
+++ b/pcsx2/Counters.cpp
@@ -156,7 +156,9 @@ static __fi void cpuRcntSet()
 		_rcntSet( i );
 
 	// sanity check!
-	if( nextCounter < 0 ) nextCounter = 0;
+	if (nextCounter < 0)
+		nextCounter = 0;
+
 	cpuSetNextEvent(nextsCounter, nextCounter); // Need to update on counter resets/target changes
 }
 
@@ -811,8 +813,9 @@ static __fi void _cpuTestOverflow( int i )
 // well forceinline it!
 __fi void rcntUpdate()
 {
-	rcntUpdate_hScanline();
 	rcntUpdate_vSync();
+	// HBlank after as VSync can do error compensation
+	rcntUpdate_hScanline();
 
 	// Update counters so that we can perform overflow and target tests.
 
@@ -835,8 +838,9 @@ __fi void rcntUpdate()
 			counters[i].sCycleT = cpuRegs.cycle - change;
 
 			// Check Counter Targets and Overflows:
-			_cpuTestTarget( i );
+			// Check Overflow first, in case the target is 0
 			_cpuTestOverflow( i );
+			_cpuTestTarget(i);
 		}
 		else counters[i].sCycleT = cpuRegs.cycle;
 	}
@@ -886,8 +890,8 @@ static __fi void rcntStartGate(bool isVblank, u32 sCycle)
 			// currectly by rcntUpdate (since it's not being scheduled for these counters)
 
 			counters[i].count += HBLANK_COUNTER_SPEED;
+			_cpuTestOverflow(i);
 			_cpuTestTarget( i );
-			_cpuTestOverflow( i );
 		}
 
 		if (!(gates & (1<<i))) continue;
diff --git a/pcsx2/IopCounters.cpp b/pcsx2/IopCounters.cpp
index 580df9e706..3ca1a02c6e 100644
--- a/pcsx2/IopCounters.cpp
+++ b/pcsx2/IopCounters.cpp
@@ -379,16 +379,16 @@ void psxCheckStartGate16(int i)
 			(psxCounters[1].mode & stoppedGateCheck) == altSourceCheck)
 		{
 			psxCounters[1].count++;
-			_rcntTestTarget(1);
 			_rcntTestOverflow(1);
+			_rcntTestTarget(1);
 		}
 
 		if ((psxCounters[3].mode & altSourceCheck) == IOPCNT_ALT_SOURCE ||
 			(psxCounters[3].mode & stoppedGateCheck) == altSourceCheck)
 		{
 			psxCounters[3].count++;
-			_rcntTestTarget(3);
 			_rcntTestOverflow(3);
+			_rcntTestTarget(3);
 		}
 	}
 
@@ -488,8 +488,8 @@ void psxRcntUpdate()
 		if (psxCounters[i].mode & IOPCNT_STOPPED)
 			continue;
 
-		_rcntTestTarget(i);
 		_rcntTestOverflow(i);
+		_rcntTestTarget(i);
 
 		// perform second target test because if we overflowed above it's possible we
 		// already shot past our target if it was very near zero.