Optimize byte code interpreter loop

README.md

@@ -23,7 +23,7 @@ The goal is to implement the actual C standard and not some subset for performan
 
 ## Limits and Errors
 
-There are still several open areas, but most targets have been reached.  The current Dhrystone performance is 59 iterations per second with byte code (11434) and 270 iterations with native code (12145 Bytes).
+There are still several open areas, but most targets have been reached.  The current Dhrystone performance is 61 iterations per second with byte code (11434) and 270 iterations with native code (12145 Bytes).
 
 ### Language
 

autotest/autotest.bat

@@ -108,6 +108,9 @@ if %errorlevel% neq 0 goto :error
 call :test randsumtest.c
 if %errorlevel% neq 0 goto :error
 
+call :test longcodetest.c
+if %errorlevel% neq 0 goto :error
+
 exit /b 0
 
 :error

autotest/longcodetest.c

@@ -0,0 +1,30 @@
+#include <assert.h>
+
+char a[200], b[200];
+bool ok = true;
+
+int main(void)
+{
+#assign ni 0
+#repeat
+	a[ni] = ni & 255;
+#assign ni ni + 1
+#until ni == 200
+
+#assign ni 0
+#repeat
+	if (ok)
+		b[ni] = ni & 255;
+#assign ni ni + 1
+#until ni == 200
+
+	int asum = 0, bsum = 0, csum;
+	for(int i=0; i<200; i++)
+	{
+		asum += a[i];
+		bsum += b[i];
+		csum += i & 255;
+	}
+	
+	return asum + bsum - 2 * csum;		
+}

include/crt.c

@@ -132,6 +132,7 @@ w2:
 		jsr	main
 pexec:
 yexec:
+zexec:
 exec:
 		jmp	inp_exit
 
@@ -149,21 +150,28 @@ pexec:
 yexec:
 		iny
 exec:
-		lda	(ip), y
+#if 0
-		sta	execjmp + 1
-		iny		
-		bmi	incip	
-execjmp:
-		jmp 	(0x0900)
-incip:
 		tya		
-		ldy	#0	
 		clc		
 		adc	ip	
 		sta	ip	
-		bcc	execjmp	
+		bcc	W1
 		inc	ip + 1		
-		bne	execjmp
+W1:		ldy #0
+#endif
+		lda	(ip), y
+		sta	execjmp + 1
+		iny		
+execjmp:
+		jmp 	(0x0900)
+zexec:
+		tya		
+		clc		
+		adc	ip	
+		sta	ip	
+		bcc	pexec	
+		inc	ip + 1		
+		bne	pexec
 bcode:		
 		byt	BC_CALL_ABS * 2
 		byt	<main
@@ -642,7 +650,7 @@ L2:		jsr	divmod32
 
 __asm inp_nop
 {
-		jmp	startup.exec
+		jmp	startup.zexec
 }
 
 #pragma	bytecode(BC_NOP, inp_nop)
@@ -2051,13 +2059,13 @@ inp_jumps:
 		sta	ip
 		bcc	W2
 		inc	ip + 1
-W2:		jmp	startup.exec		
+W2:		jmp	startup.zexec		
 W1:		sec
 		adc	ip
 		sta	ip
 		bcs	W3
 		dec	ip + 1
-W3:		jmp	startup.exec		
+W3:		jmp	startup.zexec		
 	
 inp_branchs_eq:
 		lda	accu
@@ -2163,7 +2171,7 @@ inp_jumpf:
 		adc	ip + 1
 		sta	ip + 1
 		stx	ip
-		jmp	startup.exec
+		jmp	startup.zexec
 	
 inp_branchf_eq:
 		lda	accu

oscar64/ByteCodeGenerator.cpp

@@ -1285,10 +1285,9 @@ ByteCodeBasicBlock::ByteCodeBasicBlock(void)
 {
 	mTrueJump = mFalseJump = NULL;
 	mTrueLink = mFalseLink = NULL;
-	mOffset = 0x7fffffff;
+	mOffset = -1;
-	mCopied = false;
+	mPlaced = false;
 	mAssembled = false;
-	mKnownShortBranch = false;
 	mBypassed = false;
 	mExitLive = 0;
 }
@@ -5440,10 +5439,18 @@ void ByteCodeBasicBlock::Assemble(ByteCodeGenerator* generator)
 	{
 		mAssembled = true;
 
+		int	nins = 0;
 		for (int i = 0; i < mIns.Size(); i++)
 		{
 			mIns[i].Assemble(generator, this);
+			if (mCode.Size() > nins + 240)
+			{
+				PutCode(generator, BC_NOP);
+				nins = mCode.Size();
 			}
+		}
+
+		mLinear = mCode.Size() - nins + 3;
 
 		if (this->mTrueJump)
 			this->mTrueJump->Assemble(generator);
@@ -5513,12 +5520,6 @@ void ByteCodeBasicBlock::CopyCode(ByteCodeGenerator* generator, LinkerObject* li
 {
 	int i;
 	int next, end;
-	int pos, at;
-	uint8 b;
-
-	if (!mCopied)
-	{
-		mCopied = true;
 
 	for (int i = 0; i < mRelocations.Size(); i++)
 	{
@@ -5533,50 +5534,150 @@ void ByteCodeBasicBlock::CopyCode(ByteCodeGenerator* generator, LinkerObject* li
 
 	if (mFalseJump)
 	{
-			if (mFalseJump->mOffset <= mOffset)
+		if (mFalseJump->mPlace == mPlace + 1)
-			{
+			end += PutBranch(generator, mBranch, mTrueJump->mOffset - end);
-				if (mTrueJump->mOffset <= mOffset)
+		else if (mTrueJump->mPlace == mPlace + 1)
+			end += PutBranch(generator, InvertBranchCondition(mBranch), mFalseJump->mOffset - end);
+		else
 		{
 			end += PutBranch(generator, mBranch, mTrueJump->mOffset - end);
 			end += PutBranch(generator, BC_JUMPS, mFalseJump->mOffset - end);
-					
-				}
-				else
-				{
-					end += PutBranch(generator, InvertBranchCondition(mBranch), mFalseJump->mOffset - end);
-				}
-			}
-			else
-			{
-				end += PutBranch(generator, mBranch, mTrueJump->mOffset - end);
 		}
 	}
 	else if (mTrueJump)
 	{
-			if (mTrueJump->mOffset != next)
+		if (mTrueJump->mPlace != mPlace + 1)
-			{
+			end += PutBranch(generator, mBranch, mTrueJump->mOffset - end);
-				end += PutBranch(generator, BC_JUMPS, mTrueJump->mOffset - end);
-			}
 	}
 
 	assert(end == next);
 
 	for (i = 0; i < mCode.Size(); i++)
-		{
 		mCode.Lookup(i, target[i + mOffset]);
-		}
+}
 
-		if (mTrueJump) mTrueJump->CopyCode(generator, linkerObject, target);
+void ByteCodeBasicBlock::BuildPlacement(GrowingArray<ByteCodeBasicBlock*>& placement)
-		if (mFalseJump) mFalseJump->CopyCode(generator, linkerObject, target);
+{
+	if (!mPlaced)
+	{
+		mPlaced = true;
+		mPlace = placement.Size();
+		placement.Push(this);
+
+		if (mFalseJump)
+		{
+			if (mFalseJump->mPlaced)
+				mTrueJump->BuildPlacement(placement);
+			else if (mTrueJump->mPlaced)
+				mFalseJump->BuildPlacement(placement);
+			else if (!mTrueJump->mFalseJump && !mFalseJump->mFalseJump && mTrueJump->mTrueJump == mFalseJump->mTrueJump)
+			{
+				mFalseJump->mPlaced = true;
+				mFalseJump->mPlace = placement.Size();
+				placement.Push(mFalseJump);
+
+				mTrueJump->BuildPlacement(placement);
+			}
+			else if (mTrueJump->mFalseJump == mFalseJump || mTrueJump->mTrueJump == mFalseJump)
+			{
+				mTrueJump->BuildPlacement(placement);
+				mFalseJump->BuildPlacement(placement);
+			}
+			else
+			{
+				mFalseJump->BuildPlacement(placement);
+				mTrueJump->BuildPlacement(placement);
+			}
+		}
+		else if (mTrueJump)
+		{
+			mTrueJump->BuildPlacement(placement);
+		}
 	}
 }
 
-void ByteCodeBasicBlock::CalculateOffset(int& total)
+void ByteCodeBasicBlock::InitialOffset(int& total, int& linear)
 {
+	int	size = mCode.Size();
+	if (size > 240)
+		size = 240;
+
+	mNeedsNop = linear + size > 240;
+	if (mNeedsNop)
+	{
+		total++;
+		linear = 0;
+	}
+	else
+		linear += mLinear;
+
+	mOffset = total;
+	total += mCode.Size();
+	if (mFalseJump)
+	{
+		total += 3;
+		if (mFalseJump->mPlace != mPlace + 1 && mTrueJump->mPlace != mPlace + 1)
+		{
+			total += 3;
+			linear = 0;
+		}
+	}
+	else if (mTrueJump)
+	{
+		if (mTrueJump->mPlace != mPlace + 1)
+		{
+			total += 3;
+			linear = 0;
+		}
+	}
+
+	mSize = total - mOffset;
+}
+
+bool ByteCodeBasicBlock::CalculateOffset(int& total)
+{
+	if (mNeedsNop)
+		total++;
+
+	bool	changed = total != mOffset;
+	mOffset = total;
+
+	total += mCode.Size();
+
+	if (mFalseJump)
+	{
+		if (mFalseJump->mPlace == mPlace + 1)
+			total += BranchByteSize(total, mTrueJump->mOffset);
+		else if (mTrueJump->mPlace == mPlace + 1)
+			total += BranchByteSize(total, mFalseJump->mOffset);
+		else
+		{
+			total += BranchByteSize(total, mTrueJump->mOffset);
+			total += JumpByteSize(total, mFalseJump->mOffset);
+		}
+	}
+	else if (mTrueJump)
+	{
+		if (mTrueJump->mPlace != mPlace + 1)
+			total += BranchByteSize(total, mTrueJump->mOffset);
+	}
+
+	if (mOffset + mSize != total)
+		changed = true;
+
+	mSize = total - mOffset;
+
+	return changed;
+}
+
+#if 0
 	int next;
 
 	if (mOffset > total)
 	{
+		mNeedsNop = false;
+		linear += mSize + 3;
+
 		mOffset = total;
 		next = total + mCode.Size();
 
@@ -5599,6 +5700,13 @@ void ByteCodeBasicBlock::CalculateOffset(int& total)
 					// trueJump has not been placed, but falseJump has
 
 					total = next + BranchByteSize(next, mFalseJump->mOffset);
+
+					if (linear + mTrueJump->mCode.Size() > 240)
+					{
+						mNeedsNop = true;
+						total++;
+					}
+					
 					mSize = total - mOffset;
 					mTrueJump->CalculateOffset(total);
 				}
@@ -5608,6 +5716,13 @@ void ByteCodeBasicBlock::CalculateOffset(int& total)
 				// falseJump has not been placed, but trueJump has
 
 				total = next + BranchByteSize(next, mTrueJump->mOffset);
+
+				if (linear + mFalseJump->mCode.Size() > 240)
+				{
+					mNeedsNop = true;
+					total++;
+				}
+
 				mSize = total - mOffset;
 				mFalseJump->CalculateOffset(total);
 			}
@@ -5618,6 +5733,13 @@ void ByteCodeBasicBlock::CalculateOffset(int& total)
 				// a short branch
 
 				total = next + 2;
+
+				if (linear + mFalseJump->mCode.Size() > 240)
+				{
+					mNeedsNop = true;
+					total++;
+				}
+
 				mSize = total - mOffset;
 
 				mFalseJump->CalculateOffset(total);
@@ -5634,7 +5756,15 @@ void ByteCodeBasicBlock::CalculateOffset(int& total)
 				// Small diamond so place true then false directly behind each other
 				// with short branches
 
-				mSize = mCode.Size() + 2;
+				total = next + 2;
+
+				if (linear + mFalseJump->mCode.Size() > 240)
+				{
+					mNeedsNop = true;
+					total++;
+				}
+
+				mSize = total - mOffset;
 
 				mFalseJump->mOffset = next + 2;
 				mFalseJump->mSize = mFalseJump->mCode.Size() + 2;
@@ -5717,6 +5847,8 @@ void ByteCodeBasicBlock::CalculateOffset(int& total)
 		}
 	}
 }
+#endif
+
 
 ByteCodeProcedure::ByteCodeProcedure(void)
 	: mBlocks(nullptr)
@@ -5802,17 +5934,32 @@ void ByteCodeProcedure::Compile(ByteCodeGenerator* generator, InterCodeProcedure
 	exitBlock->PutCode(generator, BC_RETURN); exitBlock->PutByte(tempSave); exitBlock->PutWord(proc->mLocalSize + 2 + tempSave);
 
 
-	int	total;
-
 	ByteCodeBasicBlock* lentryBlock = entryBlock->BypassEmptyBlocks();
 
+	GrowingArray<ByteCodeBasicBlock*>	placement(nullptr);
+
+	int	total, linear;
 	total = 0;
+	linear = 0;
 
-	lentryBlock->CalculateOffset(total);
+	lentryBlock->BuildPlacement(placement);
 
-	uint8	*	data = proc->mLinkerObject->AddSpace(total);
+	for (int i = 0; i < placement.Size(); i++)
+		placement[i]->InitialOffset(total, linear);
+
+	do {
+		progress = false;
+		total = 0;
+		for (int i = 0; i < placement.Size(); i++)
+			if (placement[i]->CalculateOffset(total))
+				progress = true;
+	} while (progress);
+
+	uint8* data = proc->mLinkerObject->AddSpace(total);
+
+	for (int i = 0; i < placement.Size(); i++)
+		placement[i]->CopyCode(generator, proc->mLinkerObject, data);
 
-	lentryBlock->CopyCode(generator, proc->mLinkerObject, data);
 	mProgSize = total; 
 }
 
@@ -5849,6 +5996,7 @@ ByteCodeGenerator::ByteCodeGenerator(Errors* errors, Linker* linker)
 	mByteCodeUsed[BC_CALL_ABS] = 1;
 	mByteCodeUsed[BC_EXIT] = 1;
 	mByteCodeUsed[BC_NATIVE] = 1;
+	mByteCodeUsed[BC_NOP] = 1;
 
 	assert(sizeof(ByteCodeNames) == 128 * sizeof(char*));
 }

oscar64/ByteCodeGenerator.h

@@ -247,8 +247,8 @@ public:
 	GrowingArray<LinkerReference>	mRelocations;
 	GrowingArray<ByteCodeBasicBlock*>	mEntryBlocks;
 
-	int						mOffset, mSize;
+	int						mOffset, mSize, mPlace, mLinear;
-	bool					mPlaced, mCopied, mKnownShortBranch, mBypassed, mAssembled, mVisited;
+	bool					mPlaced, mNeedsNop, mBypassed, mAssembled, mVisited;
 	uint32					mExitLive;
 
 	ByteCodeBasicBlock(void);
@@ -266,7 +266,10 @@ public:
 	int PutBranch(ByteCodeGenerator* generator, ByteCode code, int offset);
 
 	ByteCodeBasicBlock* BypassEmptyBlocks(void);
-	void CalculateOffset(int& total);
+	void BuildPlacement(GrowingArray<ByteCodeBasicBlock*> & placement);
+	void InitialOffset(int& total, int& linear);
+	bool CalculateOffset(int & total);
+
 	void CopyCode(ByteCodeGenerator* generator, LinkerObject * linkerObject, uint8* target);
 
 	void LongConstToAccu(int64 val);

oscar64/Emulator.cpp

@@ -640,7 +640,7 @@ int Emulator::Emulate(int startIP)
 				break;
 		}
 
-		if ((trace & 1) && ip == 0x0850)
+		if ((trace & 1) && ip == 0x0851)
 		{
 			int	accu = mMemory[BC_REG_ACCU] + 256 * mMemory[BC_REG_ACCU + 1];
 			int	ptr = mMemory[BC_REG_ADDR] + 256 * mMemory[BC_REG_ADDR + 1];

oscar64/InterCode.cpp

@@ -4408,7 +4408,7 @@ void InterCodeBasicBlock::SplitBranches(InterCodeProcedure* proc)
 	{
 		mVisited = true;
 
-		if (mTrueJump && mFalseJump && mInstructions.Size() > 2)
+		if (mTrueJump && mFalseJump && (mInstructions.Size() > 2 || mInstructions.Size() == 2 && mInstructions[0]->mCode != IC_RELATIONAL_OPERATOR))
 		{
 			InterCodeBasicBlock* block = new InterCodeBasicBlock();
 			proc->Append(block);