From 65ac00833a8b51fe9ea6f12ffdfadeb098a6c360 Mon Sep 17 00:00:00 2001
From: FICTURE7 <FICTURE7@gmail.com>
Date: Thu, 20 May 2021 16:31:45 +0400
Subject: [PATCH] Use branch instead of tailcall for recursive calls (#2282)

* Use branch instead of tailcall for recursive calls

Use a branch instead of doing a tailcall for recursive calls. This
avoids having to store the dispatch address, setting up the epilogue and
keeps guest registers in host registers for longer.

The rejit check is moved down into the entry block so that the rejit
behaviour remains the same as before.

* Set PTC version

Co-authored-by: gdkchan <gab.dark.100@gmail.com>
---
 .../Instructions/InstEmitFlowHelper.cs        |  9 +++++++-
 ARMeilleure/Translation/PTC/Ptc.cs            |  2 +-
 ARMeilleure/Translation/Translator.cs         | 22 +++++++++++--------
 3 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/ARMeilleure/Instructions/InstEmitFlowHelper.cs b/ARMeilleure/Instructions/InstEmitFlowHelper.cs
index f995ffa1..e1309a4e 100644
--- a/ARMeilleure/Instructions/InstEmitFlowHelper.cs
+++ b/ARMeilleure/Instructions/InstEmitFlowHelper.cs
@@ -144,7 +144,14 @@ namespace ARMeilleure.Instructions
         {
             bool isRecursive = immediate == context.EntryAddress;
 
-            EmitJumpTableBranch(context, Const(immediate), isRecursive);
+            if (isRecursive)
+            {
+                context.Branch(context.GetLabel(immediate));
+            }
+            else
+            {
+                EmitJumpTableBranch(context, Const(immediate), isJump: false);
+            }
         }
 
         private static void EmitNativeCall(ArmEmitterContext context, Operand nativeContextPtr, Operand funcAddr, bool isJump)
diff --git a/ARMeilleure/Translation/PTC/Ptc.cs b/ARMeilleure/Translation/PTC/Ptc.cs
index a61cf5b7..b1d55cff 100644
--- a/ARMeilleure/Translation/PTC/Ptc.cs
+++ b/ARMeilleure/Translation/PTC/Ptc.cs
@@ -28,7 +28,7 @@ namespace ARMeilleure.Translation.PTC
         private const string OuterHeaderMagicString = "PTCohd\0\0";
         private const string InnerHeaderMagicString = "PTCihd\0\0";
 
-        private const uint InternalVersion = 2279; //! To be incremented manually for each change to the ARMeilleure project.
+        private const uint InternalVersion = 2282; //! To be incremented manually for each change to the ARMeilleure project.
 
         private const string ActualDir = "0";
         private const string BackupDir = "1";
diff --git a/ARMeilleure/Translation/Translator.cs b/ARMeilleure/Translation/Translator.cs
index 81af0681..f8b074c9 100644
--- a/ARMeilleure/Translation/Translator.cs
+++ b/ARMeilleure/Translation/Translator.cs
@@ -237,13 +237,6 @@ namespace ARMeilleure.Translation
 
             Logger.StartPass(PassName.Translation);
 
-            Counter<uint> counter = null;
-
-            if (!context.HighCq)
-            {
-                EmitRejitCheck(context, out counter);
-            }
-
             EmitSynchronization(context);
 
             if (blocks[0].Address != address)
@@ -251,7 +244,7 @@ namespace ARMeilleure.Translation
                 context.Branch(context.GetLabel(address));
             }
 
-            ControlFlowGraph cfg = EmitAndGetCFG(context, blocks, out Range funcRange);
+            ControlFlowGraph cfg = EmitAndGetCFG(context, blocks, out Range funcRange, out Counter<uint> counter);
 
             ulong funcSize = funcRange.End - funcRange.Start;
 
@@ -322,8 +315,14 @@ namespace ARMeilleure.Translation
             }
         }
 
-        private static ControlFlowGraph EmitAndGetCFG(ArmEmitterContext context, Block[] blocks, out Range range)
+        private static ControlFlowGraph EmitAndGetCFG(
+            ArmEmitterContext context,
+            Block[] blocks,
+            out Range range,
+            out Counter<uint> counter)
         {
+            counter = null;
+
             ulong rangeStart = ulong.MaxValue;
             ulong rangeEnd = 0;
 
@@ -344,6 +343,11 @@ namespace ARMeilleure.Translation
                     }
                 }
 
+                if (block.Address == context.EntryAddress && !context.HighCq)
+                {
+                    EmitRejitCheck(context, out counter);
+                }
+
                 context.CurrBlock = block;
 
                 context.MarkLabel(context.GetLabel(block.Address));