Fix drop of reading from volatile with discarding result

include/crt.c

@@ -236,46 +236,40 @@ w0:
 // Clear BSS Segment
 
 #ifndef NOBSSCLEAR
-		lda #<BSSStart
+		ldx #>BSSStart
-		sta ip
+		ldy #<BSSStart
-		lda #>BSSStart
-		sta ip + 1
 
-		sec
-		lda #>BSSEnd
-		sbc #>BSSStart
-		beq w1
-		tax
 		lda #0
-		ldy #0
+		sta ip
-l1:		sta (ip), y
+l3:
+		stx ip + 1
+		cpx #>BSSEnd
+		beq w2
+l1:
+		sta (ip), y
 		iny
 		bne l1
-		inc ip + 1
-		dex
-		bne l1
-w1:
-		sec
-		lda #<BSSEnd
-		sbc #<BSSStart
-		beq w2
-		tay
-		lda #0
-l2:		dey
-		sta (ip), y
-		bne l2
-w2:
-#endif
-#ifndef NOZPCLEAR
-		ldx #<ZeroStart
-		cpx #<ZeroEnd
-		beq	w3
-l3:		sta $00, x
 		inx
-		cpx #<ZeroEnd
 		bne	l3
-w3:
+l2:
+		sta (ip), y
+		iny
+w2:
+		cpy #<BSSEnd
+		bne l2
 #endif
+
+#ifndef NOZPCLEAR
+		lda #0
+		ldx #<ZeroStart
+		bne	w3
+l4:		sta $00, x
+		inx
+w3:		
+		cpx #<ZeroEnd
+		bne l4
+#endif
+
 		lda	#<StackEnd - 2
 		sta	sp
 		lda	#>StackEnd - 2

oscar64/Declaration.cpp

@@ -387,6 +387,17 @@ bool Expression::IsRValue(void) const
 		return true;
 }
 
+bool Expression::IsVolatile(void) const
+{
+	if (mDecType->mFlags & DTF_VOLATILE)
+		return true;
+	if (mLeft && mLeft->IsVolatile())
+		return true;
+	if (mRight && mRight->IsVolatile())
+		return true;
+	return false;
+}
+
 bool Expression::IsConstRef(void) const
 {
 	if (mDecType->mType == DT_TYPE_RVALUEREF || mDecType->mType == DT_TYPE_REFERENCE)

oscar64/Declaration.h

@@ -126,6 +126,7 @@ static const uint64 DTF_VAR_ALIASING	= (1ULL << 48);
 static const uint64 DTF_FPARAM_UNUSED	= (1ULL << 49);
 static const uint64 DTF_DEPRECATED		= (1ULL << 50);
 static const uint64 DTF_FUNC_NO_RETURN	= (1ULL << 51);
+static const uint64 DTF_PLACED			= (1ULL << 52);
 
 
 
@@ -267,6 +268,7 @@ public:
 	bool IsRValue(void) const;
 	bool IsLValue(void) const;
 	bool IsConstRef(void) const;
+	bool IsVolatile(void) const;
 
 	void Dump(int ident) const;
 };

oscar64/GlobalOptimizer.cpp

@@ -189,7 +189,7 @@ bool GlobalOptimizer::CheckUnusedLocals(Expression*& exp)
 		if (vexp->mType == EX_VARIABLE)
 		{
 			Declaration* vdec = vexp->mDecValue;
-			if (vdec->mType == DT_VARIABLE && !(vdec->mFlags & (DTF_GLOBAL | DTF_STATIC)) && !(vdec->mOptFlags & OPTF_VAR_USED))
+			if (vdec->mType == DT_VARIABLE && !(vdec->mFlags & (DTF_GLOBAL | DTF_STATIC)) && !(vdec->mOptFlags & OPTF_VAR_USED) && !exp->mRight->IsVolatile())
 			{
 				exp = exp->mRight;
 				return true;

oscar64/InterCode.cpp

@@ -22913,7 +22913,7 @@ void InterCodeProcedure::Close(void)
 {
 	GrowingTypeArray	tstack(IT_NONE);
 
-	CheckFunc = !strcmp(mIdent->mString, "__computeCharsetSrc__");
+	CheckFunc = !strcmp(mIdent->mString, "main");
 	CheckCase = false;
 
 	mEntryBlock = mBlocks[0];

oscar64/InterCodeGenerator.cpp

@@ -769,6 +769,7 @@ void InterCodeGenerator::InitGlobalVariable(InterCodeModule * mod, Declaration*
 		{
 			dec->mLinkerObject->mType = LOT_INLAY;
 			dec->mInlayRegion->mInlayObject = dec->mLinkerObject;
+			dec->mLinkerObject->mFlags &= ~LOBJF_CONST;
 		}
 
 		uint8* d = var->mLinkerObject->AddSpace(var->mSize);

oscar64/NativeCodeGenerator.cpp

@@ -667,6 +667,12 @@ bool NativeCodeInstruction::IsUsedResultInstructions(NumberSet& requiredTemps)
 
 	// check side effects
 
+	if (mFlags & NCIF_VOLATILE)
+	{
+		if (mMode != ASMIM_IMPLIED && mMode != ASMIM_ZERO_PAGE)
+			used = true;
+	}
+
 	switch (mType)
 	{
 	case ASMIT_STA:
@@ -43871,7 +43877,7 @@ bool NativeCodeBasicBlock::PeepHoleOptimizerIterate1(int i, int pass)
 
 bool NativeCodeBasicBlock::PeepHoleOptimizerIterate2(int i, int pass)
 {
-	if (mIns[i].mType == ASMIT_LDA && mIns[i + 1].mType == ASMIT_LDA)
+	if (mIns[i].mType == ASMIT_LDA && mIns[i + 1].mType == ASMIT_LDA && !(mIns[i].mFlags & NCIF_VOLATILE))
 	{
 		mIns[i].mType = ASMIT_NOP; mIns[i].mMode = ASMIM_IMPLIED;;
 		return true;
@@ -51688,7 +51694,7 @@ void NativeCodeProcedure::Compile(InterCodeProcedure* proc)
 	mInterProc = proc;
 	mInterProc->mLinkerObject->mNativeProc = this;
 
-	CheckFunc = !strcmp(mInterProc->mIdent->mString, "__prepareScreen__");
+	CheckFunc = !strcmp(mInterProc->mIdent->mString, "cia_init");
 
 	int	nblocks = proc->mBlocks.Size();
 	tblocks = new NativeCodeBasicBlock * [nblocks];
@@ -52664,7 +52670,6 @@ void NativeCodeProcedure::Optimize(void)
 		if (mEntryBlock->PeepHoleOptimizer(step))
 			changed = true;
 
-
 #endif
 		if (step == 2)
 		{

oscar64/Parser.cpp

@@ -5735,6 +5735,7 @@ Declaration* Parser::ParseDeclaration(Declaration * pdec, bool variable, bool ex
 		{
 			if (ndec->mBase->mType == DT_TYPE_FUNCTION)
 			{
+				if (!(ndec->mFlags & DTF_PLACED))
 					ndec->mSection = mCodeSection;
 
 				if ((ndec->mFlags & DTF_DEFINED) && !(ndec->mFlags & DTF_REQUEST_INLINE))
@@ -13092,10 +13093,11 @@ void Parser::ParsePragma(void)
 						if (mScanner->mToken == TK_IDENT)
 						{
 							Declaration* dec = mGlobals->Lookup(mScanner->mTokenIdent);
-							if (dec && dec->mType == DT_VARIABLE && (dec->mFlags & DTF_GLOBAL))
+							if (dec && (dec->mType == DT_VARIABLE && (dec->mFlags & DTF_GLOBAL) || dec->mType == DT_CONST_FUNCTION))
 							{
 								mScanner->NextToken();
 
+								dec->mFlags |= DTF_PLACED;
 								dec->mSection = lsec;
 								if (dec->mLinkerObject)
 									dec->mLinkerObject->MoveToSection(lsec);