From f56aa60eb693ed41212960db60e01ceecf5d64c5 Mon Sep 17 00:00:00 2001
From: RSDuck <rsduck@users.noreply.github.com>
Date: Tue, 28 Jul 2020 00:44:58 +0200
Subject: [PATCH] check IRQ first then Idle loop apparently I put it this way
 for a reason

---
 src/ARM.cpp    | 46 +++++++++++++++++++++++-----------------------
 src/ARMJIT.cpp | 10 ++++++----
 2 files changed, 29 insertions(+), 27 deletions(-)

diff --git a/src/ARM.cpp b/src/ARM.cpp
index c1743ea8..7eeacb7f 100644
--- a/src/ARM.cpp
+++ b/src/ARM.cpp
@@ -660,19 +660,20 @@ void ARMv5::ExecuteJIT()
 
         if (StopExecution)
         {
-            if (Halted || IdleLoop)
-            {
-                bool idleLoop = IdleLoop;
-                IdleLoop = 0;
-                if ((Halted == 1 || idleLoop) && NDS::ARM9Timestamp < NDS::ARM9Target)
-                {
-                    NDS::ARM9Timestamp = NDS::ARM9Target;
-                }
-                break;
-            }
-
+            // this order is crucial otherwise idle loops waiting for an IRQ won't function
             if (IRQ)
                 TriggerIRQ();
+
+            if (Halted || IdleLoop)
+            {
+                if ((Halted == 1 || IdleLoop) && NDS::ARM9Timestamp < NDS::ARM9Target)
+                {
+                    Cycles = 0;
+                    NDS::ARM9Timestamp = NDS::ARM9Target;
+                }
+                IdleLoop = 0;
+                break;
+            }
         }
 
         NDS::ARM9Timestamp += Cycles;
@@ -808,22 +809,21 @@ void ARMv4::ExecuteJIT()
         else
             ARMJIT::CompileBlock(this);
 
-        // TODO optimize this shit!!!
         if (StopExecution)
         {
-            if (Halted || IdleLoop)
-            {
-                bool idleLoop = IdleLoop;
-                IdleLoop = 0;
-                if ((Halted == 1 || idleLoop) && NDS::ARM7Timestamp < NDS::ARM7Target)
-                {
-                    NDS::ARM7Timestamp = NDS::ARM7Target;
-                }
-                break;
-            }
-
             if (IRQ)
                 TriggerIRQ();
+
+            if (Halted || IdleLoop)
+            {
+                if ((Halted == 1 || IdleLoop) && NDS::ARM7Timestamp < NDS::ARM7Target)
+                {
+                    Cycles = 0;
+                    NDS::ARM7Timestamp = NDS::ARM7Target;
+                }
+                IdleLoop = 0;
+                break;
+            }
         }
 
         NDS::ARM7Timestamp += Cycles;
diff --git a/src/ARMJIT.cpp b/src/ARMJIT.cpp
index 72a31797..5b827e25 100644
--- a/src/ARMJIT.cpp
+++ b/src/ARMJIT.cpp
@@ -504,7 +504,7 @@ bool DecodeBranch(bool thumb, const FetchedInstr& instr, u32& cond, bool hasLink
     return false;
 }
 
-bool IsIdleLoop(FetchedInstr* instrs, int instrsCount)
+bool IsIdleLoop(bool thumb, FetchedInstr* instrs, int instrsCount)
 {
     // see https://github.com/dolphin-emu/dolphin/blob/master/Source/Core/Core/PowerPC/PPCAnalyst.cpp#L678
     // it basically checks if one iteration of a loop depends on another
@@ -515,9 +515,11 @@ bool IsIdleLoop(FetchedInstr* instrs, int instrsCount)
     u16 regsDisallowedToWrite = 0;
     for (int i = 0; i < instrsCount; i++)
     {
-        JIT_DEBUGPRINT("instr %d %x regs(%x %x) %x %x\n", i, instrs[i].Instr, instrs[i].Info.DstRegs, instrs[i].Info.SrcRegs, regsWrittenTo, regsDisallowedToWrite);
+        JIT_DEBUGPRINT("instr %d %08x regs(%x %x) %x %x\n", i, instrs[i].Instr, instrs[i].Info.DstRegs, instrs[i].Info.SrcRegs, regsWrittenTo, regsDisallowedToWrite);
         if (instrs[i].Info.SpecialKind == ARMInstrInfo::special_WriteMem)
             return false;
+        if (!thumb && instrs[i].Info.Kind >= ARMInstrInfo::ak_MSR_IMM && instrs[i].Info.Kind <= ARMInstrInfo::ak_MRC)
+            return false;
         if (i < instrsCount - 1 && instrs[i].Info.Branches())
             return false;
 
@@ -852,10 +854,10 @@ void CompileBlock(ARM* cpu)
                 {
                     // we might have an idle loop
                     u32 backwardsOffset = (instrs[i].Addr - target) / (thumb ? 2 : 4);
-                    if (IsIdleLoop(&instrs[i - backwardsOffset], backwardsOffset + 1))
+                    if (IsIdleLoop(thumb, &instrs[i - backwardsOffset], backwardsOffset + 1))
                     {
                         instrs[i].BranchFlags |= branch_IdleBranch;
-                        JIT_DEBUGPRINT("found %s idle loop %d in block %x\n", thumb ? "thumb" : "arm", cpu->Num, blockAddr);
+                        JIT_DEBUGPRINT("found %s idle loop %d in block %08x\n", thumb ? "thumb" : "arm", cpu->Num, blockAddr);
                     }
                 }
                 else if (hasBranched && !isBackJump && i + 1 < Config::JIT_MaxBlockSize)