From 9daf4fa62172b7c77372e02f0aa7c8653975f688 Mon Sep 17 00:00:00 2001
From: drmortalwombat <90205530+drmortalwombat@users.noreply.github.com>
Date: Sun, 18 Dec 2022 20:33:52 +0100
Subject: [PATCH] Some more cross block pointer forwarding

---
 oscar64/InterCode.cpp           | 48 +++++++++++++++++++++++++++++++++
 oscar64/InterCode.h             |  1 +
 oscar64/NativeCodeGenerator.cpp | 29 ++++++++++++++++++++
 3 files changed, 78 insertions(+)

diff --git a/oscar64/InterCode.cpp b/oscar64/InterCode.cpp
index ece36fb..f13b166 100644
--- a/oscar64/InterCode.cpp
+++ b/oscar64/InterCode.cpp
@@ -9265,6 +9265,50 @@ bool InterCodeBasicBlock::MoveTrainCrossBlock(void)
 	return changed;
 }
 
+bool InterCodeBasicBlock::ForwardLoopMovedTemp(void)
+{
+	bool changed = false;
+
+	if (!mVisited)
+	{
+		mVisited = true;
+
+		if (mTrueJump && !mFalseJump && mTrueJump->mLoopHead && mTrueJump->mNumEntries == 2)
+		{
+			InterCodeBasicBlock* eblock = nullptr;
+			if (mTrueJump->mTrueJump == mTrueJump)
+				eblock = mTrueJump->mFalseJump;
+			else if (mTrueJump->mFalseJump == mTrueJump)
+				eblock = mTrueJump->mTrueJump;
+
+			if (eblock)
+			{
+				int i = mInstructions.Size() - 1;
+				while (i >= 0)
+				{
+					if (mInstructions[i]->mCode == IC_LOAD_TEMPORARY && CanMoveInstructionBehindBlock(i) &&
+						!mTrueJump->mLocalUsedTemps[mInstructions[i]->mDst.mTemp] &&
+						!mTrueJump->mLocalModifiedTemps[mInstructions[i]->mSrc[0].mTemp])
+					{
+						eblock->mInstructions.Insert(0, mInstructions[i]);
+						mInstructions.Remove(i);
+						changed = true;
+					}
+					else
+						i--;
+				}
+			}
+		}
+
+		if (mTrueJump && mTrueJump->ForwardLoopMovedTemp())
+			changed = true;
+		if (mFalseJump && mFalseJump->ForwardLoopMovedTemp())
+			changed = true;
+	}
+
+	return changed;
+}
+
 bool InterCodeBasicBlock::ForwardDiamondMovedTemp(void)
 {
 	bool changed = false;
@@ -14187,6 +14231,10 @@ void InterCodeProcedure::Close(void)
 	}
 #endif
 
+	BuildDataFlowSets();
+	ResetVisited();
+	mEntryBlock->ForwardLoopMovedTemp();
+
 #if 1
 	do {
 		TempForwarding();
diff --git a/oscar64/InterCode.h b/oscar64/InterCode.h
index 5aea73e..9aa49f6 100644
--- a/oscar64/InterCode.h
+++ b/oscar64/InterCode.h
@@ -464,6 +464,7 @@ public:
 	bool IsLeafProcedure(void);
 
 	bool ForwardDiamondMovedTemp(void);
+	bool ForwardLoopMovedTemp(void);
 
 	bool MoveTrainCrossBlock(void);
 
diff --git a/oscar64/NativeCodeGenerator.cpp b/oscar64/NativeCodeGenerator.cpp
index 022756a..f8fba15 100644
--- a/oscar64/NativeCodeGenerator.cpp
+++ b/oscar64/NativeCodeGenerator.cpp
@@ -28004,6 +28004,22 @@ bool NativeCodeBasicBlock::PeepHoleOptimizer(NativeCodeProcedure* proc, int pass
 						mIns[i + 2].mType = ASMIT_NOP; mIns[i + 1].mMode = ASMIM_IMPLIED;
 						progress = true;
 					}
+					else if (
+						mIns[i + 0].ChangesAccuAndFlag() &&
+						(mIns[i + 1].mType == ASMIT_INC || mIns[i + 1].mType == ASMIT_DEC) &&
+						mIns[i + 2].mType == ASMIT_ORA && mIns[i + 2].mMode == ASMIM_IMMEDIATE && mIns[i + 2].mAddress == 0 &&
+						mIns[i + 1].MayBeMovedBefore(mIns[i + 0]))
+					{
+						mIns.Insert(i, mIns[i + 1]);
+						mIns[i].mLive |= LIVE_CPU_REG_A;
+						if (mIns[i + 1].RequiresYReg())
+							mIns[i].mLive |= LIVE_CPU_REG_Y;
+						if (mIns[i + 1].RequiresXReg())
+							mIns[i].mLive |= LIVE_CPU_REG_X;
+						mIns[i + 1].mLive |= LIVE_CPU_REG_Z;
+						mIns.Remove(i + 2);
+						progress = true;
+					}
 
 					if (
 						mIns[i + 0].mType == ASMIT_LDY && mIns[i + 0].mMode == ASMIM_IMMEDIATE && mIns[i + 0].mAddress <= 1 &&
@@ -28882,6 +28898,19 @@ bool NativeCodeBasicBlock::PeepHoleOptimizer(NativeCodeProcedure* proc, int pass
 					}
 #endif
 #if 1
+					else if (
+						mIns[i + 0].mType == ASMIT_LDA && mIns[i + 0].mMode == ASMIM_IMMEDIATE &&
+						mIns[i + 1].mType == ASMIT_STA && 
+						mIns[i + 2].mType == ASMIT_LDA && 
+						mIns[i + 3].mType == ASMIT_CMP && mIns[i + 3].mMode == ASMIM_IMMEDIATE && mIns[i + 3].mAddress == mIns[i + 0].mAddress && !(mIns[i + 3].mLive & (LIVE_CPU_REG_A | LIVE_CPU_REG_C)))
+					{
+						mIns[i + 1].mLive |= LIVE_CPU_REG_A;
+						mIns[i + 2].mType = ASMIT_CMP; mIns[i + 2].mLive |= LIVE_CPU_REG_Z;
+						mIns[i + 3].mType = ASMIT_NOP; mIns[i + 3].mMode = ASMIM_IMPLIED;
+
+						progress = true;
+					}
+
 					else if (
 						mIns[i + 0].mType == ASMIT_STA && mIns[i + 0].mMode == ASMIM_ZERO_PAGE && !(mIns[i + 0].mLive & LIVE_CPU_REG_A) &&
 						!mIns[i + 1].ReferencesZeroPage(mIns[i + 0].mAddress) && !mIns[i + 1].ChangesCarry() &&