From 2fc414ed6b19a4bd6c39082a545006e82c5d4fbb Mon Sep 17 00:00:00 2001
From: drmortalwombat <90205530+drmortalwombat@users.noreply.github.com>
Date: Sat, 25 Sep 2021 23:08:45 +0200
Subject: [PATCH] Byte forwardiong optimisation in native mode

---
 autotest/autotest.bat           |  6 ++++++
 autotest/byteindextest.c        |  8 +++++---
 oscar64/NativeCodeGenerator.cpp | 15 ++++++++++++---
 3 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/autotest/autotest.bat b/autotest/autotest.bat
index 9c615cf..af63c66 100644
--- a/autotest/autotest.bat
+++ b/autotest/autotest.bat
@@ -96,6 +96,12 @@ if %errorlevel% neq 0 goto :error
 ..\release\oscar64 -e -n loopdomtest.c
 if %errorlevel% neq 0 goto :error
 
+..\release\oscar64 -e byteindextest.c
+if %errorlevel% neq 0 goto :error
+
+..\release\oscar64 -e -n byteindextest.c
+if %errorlevel% neq 0 goto :error
+
 exit /b 0
 :error
 echo Failed with error #%errorlevel%.
diff --git a/autotest/byteindextest.c b/autotest/byteindextest.c
index 69bc49e..ef1a502 100644
--- a/autotest/byteindextest.c
+++ b/autotest/byteindextest.c
@@ -1,5 +1,6 @@
-// short index ops
+
 #include <stdio.h>
+#include <assert.h>
 
 char a[20];
 
@@ -10,7 +11,8 @@ int main(void)
 	char x = 0;
 	for(char i=0; i<20; i++)
 		x += a[i];
-		
-	printf("Sum %d\n", x);
+
+	assert(x == 190);
+
 	return 0;
 }
diff --git a/oscar64/NativeCodeGenerator.cpp b/oscar64/NativeCodeGenerator.cpp
index e22772c..55f6ecf 100644
--- a/oscar64/NativeCodeGenerator.cpp
+++ b/oscar64/NativeCodeGenerator.cpp
@@ -779,10 +779,19 @@ bool NativeCodeInstruction::ValueForwarding(NativeRegisterDataSet& data)
 		switch (mType)
 		{
 		case ASMIT_LDA:
-			if (data.mRegs[CPU_REG_A].mZeroPage && data.mRegs[CPU_REG_A].mValue == mAddress && !(mLive & LIVE_CPU_REG_Z))
+			if (data.mRegs[CPU_REG_A].mZeroPage && data.mRegs[CPU_REG_A].mValue == mAddress)
 			{
-				mType = ASMIT_NOP;
-				mMode = ASMIM_IMPLIED;
+				if (mLive & LIVE_CPU_REG_Z)
+				{
+					mType = ASMIT_ORA;
+					mMode = ASMIM_IMMEDIATE;
+					mAddress = 0;
+				}
+				else
+				{
+					mType = ASMIT_NOP;
+					mMode = ASMIM_IMPLIED;
+				}
 				changed = true;
 			}
 			else if (data.mRegs[mAddress].mImmediate)