From 792751e3a45055360057fdf22a5fefcbf6ad3f2a Mon Sep 17 00:00:00 2001
From: drmortalwombat <90205530+drmortalwombat@users.noreply.github.com>
Date: Tue, 25 Jan 2022 21:45:33 +0100
Subject: [PATCH] Fix error swapping global variables with negation

---
 oscar64/InterCode.cpp           |  2 +-
 oscar64/NativeCodeGenerator.cpp | 23 +++++++++++++++++++++++
 samples/games/maze3d.c          | 32 +++++++++++++++++++-------------
 3 files changed, 43 insertions(+), 14 deletions(-)

diff --git a/oscar64/InterCode.cpp b/oscar64/InterCode.cpp
index 818815e..5d7704e 100644
--- a/oscar64/InterCode.cpp
+++ b/oscar64/InterCode.cpp
@@ -9102,7 +9102,7 @@ void InterCodeProcedure::Disassemble(FILE* file)
 
 void InterCodeProcedure::Disassemble(const char* name, bool dumpSets)
 {
-#if 1
+#if 0
 #ifdef _WIN32
 	FILE* file;
 	static bool	initial = true;
diff --git a/oscar64/NativeCodeGenerator.cpp b/oscar64/NativeCodeGenerator.cpp
index b6cb5e6..3b5a995 100644
--- a/oscar64/NativeCodeGenerator.cpp
+++ b/oscar64/NativeCodeGenerator.cpp
@@ -10069,6 +10069,7 @@ bool NativeCodeBasicBlock::MoveAbsoluteLoadStoreUp(int at)
 		{
 			mIns[j].mLive |= LIVE_CPU_REG_A;
 			mIns.Insert(j + 1, mIns[at + 1]);
+			mIns[j + 1].mLive |= LIVE_CPU_REG_A;
 			mIns[at + 2].mType = ASMIT_NOP;
 			mIns[at + 2].mMode = ASMIM_IMPLIED;
 			return true;
@@ -10077,6 +10078,8 @@ bool NativeCodeBasicBlock::MoveAbsoluteLoadStoreUp(int at)
 			return false;
 		if (mIns[j].ChangesGlobalMemory())
 			return false;
+		if (mIns[j].SameEffectiveAddress(mIns[at + 1]))
+			return false;
 
 		j--;
 	}
@@ -13420,6 +13423,26 @@ bool NativeCodeBasicBlock::PeepHoleOptimizer(int pass)
 						mIns[i + 2].mType = ASMIT_NOP; mIns[i + 2].mMode = ASMIM_IMPLIED;
 						progress = true;
 					}
+					else if (
+						mIns[i + 0].mType == ASMIT_TAX &&
+						!mIns[i + 1].ChangesXReg() && !mIns[i + 1].UsesAccu() &&
+						mIns[i + 2].mType == ASMIT_STX && !(mIns[i + 2].mLive & LIVE_CPU_REG_X))
+					{
+						mIns[i + 0].mType = ASMIT_NOP; mIns[i + 0].mMode = ASMIM_IMPLIED;
+						mIns[i + 2].mType = ASMIT_STA;
+						mIns[i + 1].mLive |= LIVE_CPU_REG_A;
+						progress = true;
+					}
+					else if (
+						mIns[i + 0].mType == ASMIT_TAY &&
+						!mIns[i + 1].ChangesYReg() && !mIns[i + 1].UsesAccu() &&
+						mIns[i + 2].mType == ASMIT_STY && !(mIns[i + 2].mLive & LIVE_CPU_REG_Y))
+					{
+						mIns[i + 0].mType = ASMIT_NOP; mIns[i + 0].mMode = ASMIM_IMPLIED;
+						mIns[i + 2].mType = ASMIT_STA;
+						mIns[i + 1].mLive |= LIVE_CPU_REG_A;
+						progress = true;
+					}
 					else if (
 						mIns[i + 0].mType == ASMIT_SEC &&
 						mIns[i + 1].mType == ASMIT_TXA &&
diff --git a/samples/games/maze3d.c b/samples/games/maze3d.c
index 870c904..2afe5c5 100644
--- a/samples/games/maze3d.c
+++ b/samples/games/maze3d.c
@@ -35,7 +35,8 @@ void maze_init(void)
 }
 
 
-static char zxdist[] = {18, 6, 3, 2, 1, 0};
+static char zxdist0[] = {18, 6, 4, 3, 2, 1, 0};
+static char zxdist1[] = { 9, 5, 3, 2, 1, 0, 0};
 
 // Put one  char on screen
 inline void screen_put(byte x, byte y, char ch, char color)
@@ -56,11 +57,11 @@ inline char screen_get(byte x, byte y)
 
 sbyte	px = 1, py = 3, dx = 1, dy = 0;
 
-void maze_draw(void)
+void maze_draw(const char * zxdist)
 {
 	sbyte	ix = px, iy = py;
 	sbyte	sx = 0;
-	for(char i=0; i<6; i++)
+	for(char i=0; i<7; i++)
 	{
 		sbyte	tx = 20 - zxdist[i];
 
@@ -167,31 +168,35 @@ int main(void)
 	{
 		float	z = 0.5 + i;
 		float	x = 9.0 / z;
-		printf("%d : %f / %f : %d\n", i, z, x, (int)x);
+		printf("%d : %f / %f : %d\n", i, z, x, (int)(x + 0.5));
 	}
 	return 0;
-#endif
+#else
 	bool	rotate = false;
 
 	for(;;)
 	{
-		maze_draw();
+		maze_draw(zxdist0);
 		joy_poll(1);
 
-		sbyte tx = px - dx * joyy[1];
-		sbyte ty = py - dy * joyy[1];
-
-		if (maze[ty][tx] != '#')
+		if (joyy[1])
 		{
-			px = tx;
-			py = ty;
+			sbyte tx = px - dx * joyy[1];
+			sbyte ty = py - dy * joyy[1];
+
+			if (maze[ty][tx] != '#')
+			{
+				px = tx;
+				py = ty;
+				maze_draw(zxdist1);
+			}
 		}
 
 		if (!rotate)
 		{
 			if (joyx[1] == 1)
 			{
-				sbyte	t = dx; dx = - dy; dy = t;
+				sbyte	t = dx; dx = -dy; dy = t;
 				rotate = true;
 			}
 			else if (joyx[1] == -1)
@@ -205,6 +210,7 @@ int main(void)
 			rotate = false;
 		}
 	}
+#endif
 
 	return 0;
 }