From 880abea32efcd84b89e31290a1eb274dbc8bb665 Mon Sep 17 00:00:00 2001
From: drmortalwombat <90205530+drmortalwombat@users.noreply.github.com>
Date: Thu, 29 May 2025 13:38:00 +0200
Subject: [PATCH] Shortcut tiny jump detours after placement

---
 oscar64/NativeCodeGenerator.cpp | 28 ++++++++++++++++++++++++++++
 oscar64/NativeCodeGenerator.h   |  1 +
 2 files changed, 29 insertions(+)

diff --git a/oscar64/NativeCodeGenerator.cpp b/oscar64/NativeCodeGenerator.cpp
index cfccc11..3f3caf0 100644
--- a/oscar64/NativeCodeGenerator.cpp
+++ b/oscar64/NativeCodeGenerator.cpp
@@ -54908,6 +54908,31 @@ void NativeCodeBasicBlock::BuildPlacement(ExpandingArray<NativeCodeBasicBlock*>&
 	}
 }
 
+void NativeCodeBasicBlock::OptimizePlacement(void)
+{
+	if (!mFalseJump && mTrueJump && !mTrueJump->mFalseJump && mTrueJump->mTrueJump && mTrueJump->mTrueJump->mPlace == mPlace + 1 && mTrueJump->mCode.Size() <= 3)
+	{
+		for (int i = 0; i < mTrueJump->mRelocations.Size(); i++)
+		{
+			LinkerReference	rl = mTrueJump->mRelocations[i];
+			rl.mOffset += mCode.Size();
+			if (rl.mFlags & LREF_INBLOCK)
+			{
+				rl.mRefOffset += mCode.Size();
+				rl.mFlags &= ~LREF_INBLOCK;
+			}
+			mRelocations.Push(rl);
+		}
+		for (int i = 0; i < mTrueJump->mCode.Size(); i++)
+			mCode.Push(mTrueJump->mCode[i]);
+		mTrueJump->mEntryBlocks.RemoveAll(this);
+		mTrueJump->mNumEntries--;
+		mTrueJump = mTrueJump->mTrueJump;
+		mTrueJump->mEntryBlocks.Push(this);
+		mTrueJump->mNumEntries++;
+	}
+}
+
 void NativeCodeBasicBlock::InitialOffset(int& total)
 {
 	mAsmFromJump = -1;
@@ -56064,6 +56089,9 @@ void NativeCodeProcedure::Assemble(void)
 
 	mEntryBlock->BuildPlacement(placement);
 
+	for (int i = 0; i < placement.Size(); i++)
+		placement[i]->OptimizePlacement();;
+
 	for (int i = 0; i < placement.Size(); i++)
 		placement[i]->InitialOffset(total);
 
diff --git a/oscar64/NativeCodeGenerator.h b/oscar64/NativeCodeGenerator.h
index 8fbc0e9..62a43f9 100644
--- a/oscar64/NativeCodeGenerator.h
+++ b/oscar64/NativeCodeGenerator.h
@@ -303,6 +303,7 @@ public:
 	int LeadsInto(NativeCodeBasicBlock* block, int dist);
 	NativeCodeBasicBlock* PlaceSequence(ExpandingArray<NativeCodeBasicBlock*>& placement, NativeCodeBasicBlock* block);
 	void BuildPlacement(ExpandingArray<NativeCodeBasicBlock*>& placement);
+	void OptimizePlacement(void);
 	void InitialOffset(int& total);
 	bool CalculateOffset(int& total, bool final);