From a3bf7296bb5f38512c63dd3cedfb4395bde09c82 Mon Sep 17 00:00:00 2001
From: drmortalwombat <90205530+drmortalwombat@users.noreply.github.com>
Date: Tue, 9 Jul 2024 11:24:02 +0200
Subject: [PATCH] Reduce index register usage, where ORA Imm would suffice

---
 oscar64/InterCode.cpp           | 10 +++++++++-
 oscar64/NativeCodeGenerator.cpp | 26 +++++++++++++++++++++++++-
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/oscar64/InterCode.cpp b/oscar64/InterCode.cpp
index 6a83dde..a60311f 100644
--- a/oscar64/InterCode.cpp
+++ b/oscar64/InterCode.cpp
@@ -8284,6 +8284,14 @@ void InterCodeBasicBlock::UpdateLocalIntegerRangeSetsForward(const GrowingVariab
 						vr.mMaxState = vr.mMinState = IntegerValueRange::S_UNBOUND;
 					break;
 #if 1
+				case IA_DIVU:
+					vr = mProc->mLocalValueRange[ins->mSrc[1].mTemp];
+					vr.LimitMin(0);
+					vr.mMinValue = 0;
+					if (ins->mSrc[0].mTemp < 0 && ins->mSrc[0].mIntConst > 1)
+						vr.mMaxValue /= ins->mSrc[0].mIntConst;
+					break;
+
 				case IA_MODU:
 					vr.LimitMin(0);
 					if (ins->mSrc[0].mTemp < 0)
@@ -15229,7 +15237,7 @@ void InterCodeBasicBlock::EliminateDoubleLoopCounter(void)
 
 				if (lcs.Size() >= 2)
 				{
-					int	loop = -1;
+					int64	loop = -1;
 					int k = 0;
 					while (k < lcs.Size() && !lcs[k].mCmp)
 						k++;
diff --git a/oscar64/NativeCodeGenerator.cpp b/oscar64/NativeCodeGenerator.cpp
index 4607831..6520e6b 100644
--- a/oscar64/NativeCodeGenerator.cpp
+++ b/oscar64/NativeCodeGenerator.cpp
@@ -42175,6 +42175,20 @@ bool NativeCodeBasicBlock::PeepHoleOptimizerIterate1(int i, int pass)
 		mIns[i].mType = ASMIT_ASL;
 		return true;
 	}
+	else if (mIns[i].mType == ASMIT_TAY && !(mIns[i].mLive & LIVE_CPU_REG_Y))
+	{
+		mIns[i].mType = ASMIT_ORA;
+		mIns[i].mMode = ASMIM_IMMEDIATE;
+		mIns[i].mAddress = 0;
+		return true;
+	}
+	else if (mIns[i].mType == ASMIT_TAX && !(mIns[i].mLive & LIVE_CPU_REG_X))
+	{
+		mIns[i].mType = ASMIT_ORA;
+		mIns[i].mMode = ASMIM_IMMEDIATE;
+		mIns[i].mAddress = 0;
+		return true;
+	}
 
 	int	apos;
 	if (mIns[i].mMode == ASMIM_INDIRECT_Y && FindGlobalAddress(i, mIns[i].mAddress, apos))
@@ -44400,6 +44414,16 @@ bool NativeCodeBasicBlock::PeepHoleOptimizerIterate3(int i, int pass)
 		mIns.Remove(i + 2);
 		return true;
 	}
+	else if (
+		mIns[i + 0].ChangesAccuAndFlag() && mIns[i + 0].mMode == ASMIM_IMPLIED &&
+		(mIns[i + 1].mType == ASMIT_INX || mIns[i + 1].mType == ASMIT_DEX || mIns[i + 1].mType == ASMIT_INY || mIns[i + 1].mType == ASMIT_DEY) &&
+		mIns[i + 2].mType == ASMIT_ORA && mIns[i + 2].mMode == ASMIM_IMMEDIATE && mIns[i + 2].mAddress == 0)
+	{
+		mIns[i + 2] = mIns[i + 0];
+		mIns[i + 0].mType = ASMIT_NOP; mIns[i + 0].mMode = ASMIM_IMPLIED;
+		mIns[i + 1].mLive |= LIVE_CPU_REG_A;
+		return true;
+	}
 	else if (
 		mIns[i + 0].mType == ASMIT_LDA &&
 		mIns[i + 1].mType == ASMIT_STA &&
@@ -49486,7 +49510,7 @@ void NativeCodeProcedure::Compile(InterCodeProcedure* proc)
 	mInterProc = proc;
 	mInterProc->mLinkerObject->mNativeProc = this;
 
-	CheckFunc = !strcmp(mInterProc->mIdent->mString, "main");
+	CheckFunc = !strcmp(mInterProc->mIdent->mString, "clz");
 
 	int	nblocks = proc->mBlocks.Size();
 	tblocks = new NativeCodeBasicBlock * [nblocks];