From 7c0db6161da94aa7fd549291d019dca32fa51f3d Mon Sep 17 00:00:00 2001
From: drmortalwombat <90205530+drmortalwombat@users.noreply.github.com>
Date: Thu, 1 Jun 2023 22:23:08 +0200
Subject: [PATCH] Optimize some pointer arithmetic

---
 oscar64/NativeCodeGenerator.cpp | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/oscar64/NativeCodeGenerator.cpp b/oscar64/NativeCodeGenerator.cpp
index d5a8df5..6db3efd 100644
--- a/oscar64/NativeCodeGenerator.cpp
+++ b/oscar64/NativeCodeGenerator.cpp
@@ -37836,6 +37836,35 @@ bool NativeCodeBasicBlock::PeepHoleOptimizer(NativeCodeProcedure* proc, int pass
 						}
 					}
 #endif
+#if 1
+					if (mIns[i + 0].mType == ASMIT_CLC &&
+						mIns[i + 1].mType == ASMIT_LDA && mIns[i + 1].mMode == ASMIM_IMMEDIATE_ADDRESS &&
+						mIns[i + 2].mType == ASMIT_ADC && mIns[i + 2].mMode == ASMIM_ZERO_PAGE &&
+						mIns[i + 3].mType == ASMIT_STA && mIns[i + 3].mMode == ASMIM_ZERO_PAGE && mIns[i + 2].mAddress != mIns[i + 3].mAddress &&
+						mIns[i + 4].mType == ASMIT_LDA && mIns[i + 4].mMode == ASMIM_IMMEDIATE_ADDRESS && mIns[i + 4].mLinkerObject == mIns[i + 1].mLinkerObject && mIns[i + 4].mAddress == mIns[i + 1].mAddress &&
+						mIns[i + 5].mType == ASMIT_ADC && mIns[i + 5].mMode == ASMIM_ZERO_PAGE && mIns[i + 5].mAddress == mIns[i + 2].mAddress + 1 &&
+						mIns[i + 6].mType == ASMIT_STA && mIns[i + 6].mMode == ASMIM_ZERO_PAGE && mIns[i + 6].mAddress == mIns[i + 3].mAddress + 1 &&
+						!(mIns[i + 6].mLive & LIVE_CPU_REG_A))
+					{
+						int yval = RetrieveYValue(i);
+						proc->ResetPatched();
+						if (CheckForwardSumYPointer(this, mIns[i + 3].mAddress, mIns[i + 3].mAddress, mIns[i + 2], i + 7, yval))
+						{
+							proc->ResetPatched();
+							if (PatchForwardSumYPointer(this, mIns[i + 3].mAddress, mIns[i + 3].mAddress, mIns[i + 2], i + 7, yval))
+							{
+								mIns[i + 2].mType = ASMIT_NOP; mIns[i + 2].mMode = ASMIM_IMPLIED;
+
+								progress = true;
+
+								if (mTrueJump)
+									mTrueJump->CheckLive();
+								if (mFalseJump)
+									mFalseJump->CheckLive();
+							}
+						}
+					}
+#endif
 #if 1
 					if (mIns[i + 0].mType == ASMIT_CLC &&
 						mIns[i + 1].mType == ASMIT_LDA && mIns[i + 1].mMode == ASMIM_ZERO_PAGE &&