From ce0ac302808657c540ced85e2113aaaacdca20a6 Mon Sep 17 00:00:00 2001
From: drmortalwombat <90205530+drmortalwombat@users.noreply.github.com>
Date: Thu, 19 Sep 2024 08:12:04 +0200
Subject: [PATCH] Fix value propagation in loop dependency analysis

---
 oscar64/InterCode.cpp | 31 ++++++++++++++++++++++++++++---
 oscar64/InterCode.h   |  2 ++
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/oscar64/InterCode.cpp b/oscar64/InterCode.cpp
index 47fbfd1..a3818ae 100644
--- a/oscar64/InterCode.cpp
+++ b/oscar64/InterCode.cpp
@@ -109,6 +109,30 @@ void IntegerValueRange::LimitMinWeak(int64 value)
 
 }
 
+void IntegerValueRange::AddConstValue(InterType type, int64 value)
+{
+	if (value > 0 && IntegerValueRange::S_WEAK)
+		mMaxState = S_UNBOUND;
+	else if (value < 0 && mMinState == S_WEAK)
+		mMinState = S_UNBOUND;
+
+	if (type == IT_INT8 && value >= 128 && mMaxState != S_BOUND)
+		mMinState = S_UNBOUND;
+
+	mMinValue += value;
+	mMaxValue += value;
+
+	if (type == IT_INT8)
+	{
+		if (mMinState == S_BOUND && mMinValue < -255 || mMaxState == S_BOUND && mMaxValue > 255)
+		{
+			LimitMax(255);
+			LimitMin(-128);
+		}
+	}
+}
+
+
 void IntegerValueRange::LimitMaxWeak(int64 value)
 {
 	if (mMaxState == S_UNBOUND || mMaxState != S_UNKNOWN && mMaxValue > value)
@@ -15187,6 +15211,7 @@ bool InterCodeBasicBlock::SingleTailLoopOptimization(const NumberSet& aliasedPar
 									ains->mSrc[0].mTemp = -1;
 									ains->mSrc[0].mIntConst = s;
 									tail->AppendBeforeBranch(ains);
+									ains->mDst.mRange.AddConstValue(ains->mDst.mType, s);
 
 									indexScale[ains->mDst.mTemp] = s;
 
@@ -15219,7 +15244,7 @@ bool InterCodeBasicBlock::SingleTailLoopOptimization(const NumberSet& aliasedPar
 									ains->mSrc[0] = nins->mSrc[0];
 									ains->mSrc[0].mIntConst *= indexScale[lins->mSrc[0].mTemp];
 									tail->AppendBeforeBranch(ains);
-									ains->mDst.mRange.mMaxValue += ains->mSrc[0].mIntConst;
+									ains->mDst.mRange.AddConstValue(ains->mDst.mType, ains->mSrc[0].mIntConst);
 
 									indexScale[ains->mDst.mTemp] = (int)ains->mSrc[0].mIntConst;
 
@@ -15254,7 +15279,7 @@ bool InterCodeBasicBlock::SingleTailLoopOptimization(const NumberSet& aliasedPar
 								ains->mSrc[0].mTemp = -1;
 								ains->mSrc[0].mIntConst = s;
 								tail->AppendBeforeBranch(ains);
-								ains->mDst.mRange.mMaxValue += ains->mSrc[0].mIntConst;
+								ains->mDst.mRange.AddConstValue(ains->mDst.mType, s);
 
 								indexScale[ains->mDst.mTemp] = s;
 
@@ -22074,7 +22099,7 @@ void InterCodeProcedure::Close(void)
 {
 	GrowingTypeArray	tstack(IT_NONE);
 
-	CheckFunc = !strcmp(mIdent->mString, "bar2");
+	CheckFunc = !strcmp(mIdent->mString, "main");
 	CheckCase = false;
 
 	mEntryBlock = mBlocks[0];
diff --git a/oscar64/InterCode.h b/oscar64/InterCode.h
index 3d5e190..2c8214d 100644
--- a/oscar64/InterCode.h
+++ b/oscar64/InterCode.h
@@ -185,6 +185,8 @@ public:
 	
 	void LimitMinWeak(int64 value);
 	void LimitMaxWeak(int64 value);
+
+	void AddConstValue(InterType type, int64 value);
 };