From da9546cb2f7f81178412d7d5c2df7f5582636b8d Mon Sep 17 00:00:00 2001
From: Sintendo <bram.speeckaert@gmail.com>
Date: Tue, 21 Sep 2021 23:09:25 +0200
Subject: [PATCH] Jit64: Merge subfx and subfcx

Again, logic and optimizations are mostly the same so it makes sense.
---
 Source/Core/Core/PowerPC/Jit64/Jit.h          |  1 -
 .../Core/Core/PowerPC/Jit64/Jit64_Tables.cpp  |  4 +-
 .../Core/Core/PowerPC/Jit64/Jit_Integer.cpp   | 59 +++++++------------
 3 files changed, 22 insertions(+), 42 deletions(-)

diff --git a/Source/Core/Core/PowerPC/Jit64/Jit.h b/Source/Core/Core/PowerPC/Jit64/Jit.h
index 5916093295..a0874de36b 100644
--- a/Source/Core/Core/PowerPC/Jit64/Jit.h
+++ b/Source/Core/Core/PowerPC/Jit64/Jit.h
@@ -232,7 +232,6 @@ public:
 
   void subfic(UGeckoInstruction inst);
   void subfx(UGeckoInstruction inst);
-  void subfcx(UGeckoInstruction inst);
 
   void twX(UGeckoInstruction inst);
 
diff --git a/Source/Core/Core/PowerPC/Jit64/Jit64_Tables.cpp b/Source/Core/Core/PowerPC/Jit64/Jit64_Tables.cpp
index 2d77df1d38..2a5b77b258 100644
--- a/Source/Core/Core/PowerPC/Jit64/Jit64_Tables.cpp
+++ b/Source/Core/Core/PowerPC/Jit64/Jit64_Tables.cpp
@@ -170,8 +170,8 @@ constexpr std::array<GekkoOPTemplate, 107> s_table31{{
     {616, &Jit64::negx},      // negox
     {40, &Jit64::subfx},      // subfx
     {552, &Jit64::subfx},     // subfox
-    {8, &Jit64::subfcx},       // subfcx
-    {520, &Jit64::subfcx},     // subfcox
+    {8, &Jit64::subfx},       // subfcx
+    {520, &Jit64::subfx},     // subfcox
     {136, &Jit64::arithXex},  // subfex
     {648, &Jit64::arithXex},  // subfeox
     {232, &Jit64::arithXex},  // subfmex
diff --git a/Source/Core/Core/PowerPC/Jit64/Jit_Integer.cpp b/Source/Core/Core/PowerPC/Jit64/Jit_Integer.cpp
index c1a6846d16..e5f5071bc6 100644
--- a/Source/Core/Core/PowerPC/Jit64/Jit_Integer.cpp
+++ b/Source/Core/Core/PowerPC/Jit64/Jit_Integer.cpp
@@ -938,10 +938,13 @@ void Jit64::subfx(UGeckoInstruction inst)
   INSTRUCTION_START
   JITDISABLE(bJITIntegerOff);
   int a = inst.RA, b = inst.RB, d = inst.RD;
+  const bool carry = !(inst.SUBOP10 & (1 << 5));
 
   if (a == b)
   {
     gpr.SetImmediate32(d, 0);
+    if (carry)
+      FinalizeCarry(true);
     if (inst.OE)
       GenerateConstantOverflow(false);
   }
@@ -949,6 +952,8 @@ void Jit64::subfx(UGeckoInstruction inst)
   {
     s32 i = gpr.SImm32(b), j = gpr.SImm32(a);
     gpr.SetImmediate32(d, i - j);
+    if (carry)
+      FinalizeCarry(j == 0 || Interpreter::Helper_Carry((u32)i, 0u - (u32)j));
     if (inst.OE)
       GenerateConstantOverflow((s64)i - (s64)j);
   }
@@ -963,16 +968,20 @@ void Jit64::subfx(UGeckoInstruction inst)
     {
       if (d != b)
         MOV(32, Rd, Rb);
+      if (carry)
+        FinalizeCarry(true);
       if (inst.OE)
         GenerateConstantOverflow(false);
     }
     else if (d == b)
     {
       SUB(32, Rd, Imm32(j));
+      if (carry)
+        FinalizeCarry(CC_NC);
       if (inst.OE)
         GenerateOverflow();
     }
-    else if (Rb.IsSimpleReg() && !inst.OE)
+    else if (Rb.IsSimpleReg() && !carry && !inst.OE)
     {
       LEA(32, Rd, MDisp(Rb.GetSimpleReg(), -j));
     }
@@ -980,6 +989,8 @@ void Jit64::subfx(UGeckoInstruction inst)
     {
       MOV(32, Rd, Rb);
       SUB(32, Rd, Imm32(j));
+      if (carry)
+        FinalizeCarry(CC_NC);
       if (inst.OE)
         GenerateOverflow();
     }
@@ -993,6 +1004,8 @@ void Jit64::subfx(UGeckoInstruction inst)
     if (d != a)
       MOV(32, Rd, Ra);
     NEG(32, Rd);
+    if (carry)
+      FinalizeCarry(CC_NC);
     if (inst.OE)
       GenerateOverflow();
   }
@@ -1003,21 +1016,21 @@ void Jit64::subfx(UGeckoInstruction inst)
     RCX64Reg Rd = gpr.Bind(d, RCMode::Write);
     RegCache::Realize(Ra, Rb, Rd);
 
-    if (d == b)
-    {
-      SUB(32, Rd, Ra);
-    }
-    else if (d == a)
+    if (d == a && d != b)
     {
+      // special case, because sub isn't reversible
       MOV(32, R(RSCRATCH), Ra);
       MOV(32, Rd, Rb);
       SUB(32, Rd, R(RSCRATCH));
     }
     else
     {
-      MOV(32, Rd, Rb);
+      if (d != b)
+        MOV(32, Rd, Rb);
       SUB(32, Rd, Ra);
     }
+    if (carry)
+      FinalizeCarry(CC_NC);
     if (inst.OE)
       GenerateOverflow();
   }
@@ -1818,38 +1831,6 @@ void Jit64::arithXex(UGeckoInstruction inst)
     ComputeRC(d);
 }
 
-void Jit64::subfcx(UGeckoInstruction inst)
-{
-  INSTRUCTION_START
-  JITDISABLE(bJITIntegerOff);
-  int a = inst.RA, b = inst.RB, d = inst.RD;
-
-  {
-    RCOpArg Ra = gpr.Use(a, RCMode::Read);
-    RCOpArg Rb = gpr.Use(b, RCMode::Read);
-    RCX64Reg Rd = gpr.Bind(d, RCMode::Write);
-    RegCache::Realize(Ra, Rb, Rd);
-
-    if (d == a && d != b)
-    {
-      // special case, because sub isn't reversible
-      MOV(32, R(RSCRATCH), Ra);
-      MOV(32, Rd, Rb);
-      SUB(32, Rd, R(RSCRATCH));
-    }
-    else
-    {
-      if (d != b)
-        MOV(32, Rd, Rb);
-      SUB(32, Rd, Ra);
-    }
-  }
-
-  FinalizeCarryOverflow(inst.OE, true);
-  if (inst.Rc)
-    ComputeRC(d);
-}
-
 void Jit64::rlwinmx(UGeckoInstruction inst)
 {
   INSTRUCTION_START