From d27f2d6e20dd937a2c24310e073b32e39572646f Mon Sep 17 00:00:00 2001
From: James Roseborough <james.roseborough@luaj.org>
Date: Tue, 10 Aug 2010 17:46:17 +0000
Subject: [PATCH] Improve bytecode generation.

---
 src/jse/org/luaj/vm2/luajc/BasicBlock.java  | 54 +--------------------
 src/jse/org/luaj/vm2/luajc/JavaBuilder.java |  6 +--
 src/jse/org/luaj/vm2/luajc/ProtoInfo.java   | 30 +++++++-----
 src/jse/org/luaj/vm2/luajc/UpvalInfo.java   | 22 ++++++---
 4 files changed, 35 insertions(+), 77 deletions(-)

diff --git a/src/jse/org/luaj/vm2/luajc/BasicBlock.java b/src/jse/org/luaj/vm2/luajc/BasicBlock.java
index 2aec9efa..8c702f07 100644
--- a/src/jse/org/luaj/vm2/luajc/BasicBlock.java
+++ b/src/jse/org/luaj/vm2/luajc/BasicBlock.java
@@ -14,13 +14,8 @@ public class BasicBlock {
 	BasicBlock[] prev;  // previous basic blocks (0-n of these)
 	BasicBlock[] next;  // next basic blocks (0, 1, or 2 of these)
 	
-	short[] ninputs;    // number of input values per slot, >0 means is phi variable
-	VarInfo[][] inputs;   // variables for each input, -1=closed/undefined, 1,2...=revisionof that variable
-	
 	public BasicBlock(Prototype p, int pc0) {
 		this.pc0 = this.pc1 = pc0;
-		this.ninputs = new short[p.maxstacksize];
-		this.inputs = new VarInfo[p.maxstacksize][];
 	}
 	
 	public String toString() {
@@ -28,18 +23,7 @@ public class BasicBlock {
 		sb.append( (pc0+1)+"-"+(pc1+1)
 				+(prev!=null? "  prv: "+str(prev,1): "")
 				+(next!=null? "  nxt: "+str(next,0): "")
-				+"\n " );
-		for ( int i=0; i<ninputs.length; i++ ) {
-			if ( ninputs[i] < 0 )
-				sb.append( "     x " );
-			else if ( ninputs[i] == 0 )
-				sb.append( "     - " );
-			else {
-				sb.append( "    "+inputs[i][0] );
-				for ( int j=1; j<ninputs[i]; j++ )
-					sb.append(","+inputs[i][j]);
-			}
-		}
+				+"\n" );
 		return sb.toString();
 	}
 	
@@ -121,7 +105,6 @@ public class BasicBlock {
 		int sbx,j;
 		int[] code = p.code;
 		int n = code.length;
-		boolean[] branchdests = new boolean[n];
 		for ( int i=0; i<n; i++ ) {
 			int ins = code[i];
 			switch ( Lua.GET_OPCODE( ins ) ) {
@@ -162,41 +145,6 @@ public class BasicBlock {
 		}
 	}
 
-	public boolean mergeSlotInput(int slot, VarInfo v) {
-		int n = ninputs[slot];
-		if ( n == -1 )
-			return false;
-		if ( v == VarInfo.INVALID) {
-			ninputs[slot] = -1;
-			inputs[slot] = null;
-			return true;
-		} 
-		if ( n == 0 ) {
-			ninputs[slot] = 1;
-			inputs[slot] = new VarInfo[] { v };
-			return true;
-		}
-		for ( int i=0; i<n; i++ )
-			if ( inputs[slot][i] == v )
-				return false;
-		if ( n+1 > inputs[slot].length ) {
-			VarInfo[] s = inputs[slot];
-			inputs[slot] = new VarInfo[(n+1)*2];
-			System.arraycopy(s, 0, inputs[slot], 0, n);
-		}
-		inputs[slot][n] = v;
-		ninputs[slot]++;
-		return true;
-	}
-	
-	boolean includesVar(int slot, VarInfo v) {
-		int n = ninputs[slot];
-		for ( int i=0; i<n; i++ )
-			if ( inputs[slot][i] == v )
-				return true;
-		return false;
-	}
-
 	public static BasicBlock[] sortDepthFirst(BasicBlock[] blocks) {
 		Vector list = new Vector();
 		Hashtable seen = new Hashtable();
diff --git a/src/jse/org/luaj/vm2/luajc/JavaBuilder.java b/src/jse/org/luaj/vm2/luajc/JavaBuilder.java
index c4a5bcbd..267fb2b5 100644
--- a/src/jse/org/luaj/vm2/luajc/JavaBuilder.java
+++ b/src/jse/org/luaj/vm2/luajc/JavaBuilder.java
@@ -198,7 +198,7 @@ public class JavaBuilder {
 		// create the fields
 		for ( int i=0; i<p.nups; i++ ) {
 			boolean isrw = pi.isReadWriteUpvalue( pi.upvals[i] ); 
-			Type uptype = isrw? TYPE_LOCALUPVALUE: TYPE_LUAVALUE;
+			Type uptype = isrw? (Type) TYPE_LOCALUPVALUE: (Type) TYPE_LUAVALUE;
 			FieldGen fg = new FieldGen(0, uptype, upvalueName(i), cp);
 			cg.addField(fg.getField());
 		}
@@ -610,7 +610,7 @@ public class JavaBuilder {
 
 	public void closureInitUpvalueFromUpvalue(String protoname, int newup, int upindex) {
 		boolean isrw = pi.isReadWriteUpvalue( pi.upvals[upindex] ); 
-		Type uptype = isrw? TYPE_LOCALUPVALUE: TYPE_LUAVALUE;
+		Type uptype = isrw? (Type) TYPE_LOCALUPVALUE: (Type) TYPE_LUAVALUE;
 		String srcname = upvalueName(upindex);
 		String destname = upvalueName(newup);
 		append(InstructionConstants.THIS);
@@ -620,7 +620,7 @@ public class JavaBuilder {
 
 	public void closureInitUpvalueFromLocal(String protoname, int newup, int pc, int srcslot) {
 		boolean isrw = pi.isReadWriteUpvalue( pi.vars[srcslot][pc].upvalue ); 
-		Type uptype = isrw? TYPE_LOCALUPVALUE: TYPE_LUAVALUE;
+		Type uptype = isrw? (Type) TYPE_LOCALUPVALUE: (Type) TYPE_LUAVALUE;
 		String destname = upvalueName(newup);
 		int index = findSlotIndex( srcslot, isrw );
 		append(new ALOAD(index));
diff --git a/src/jse/org/luaj/vm2/luajc/ProtoInfo.java b/src/jse/org/luaj/vm2/luajc/ProtoInfo.java
index 94af7867..30bedb24 100644
--- a/src/jse/org/luaj/vm2/luajc/ProtoInfo.java
+++ b/src/jse/org/luaj/vm2/luajc/ProtoInfo.java
@@ -22,7 +22,7 @@ public class ProtoInfo {
 	public final Prototype prototype;     // the prototype that this info is about
 	public final ProtoInfo[] subprotos;   // one per enclosed prototype, or null
 	public final BasicBlock[] blocks;     // basic block analysis of code branching
-	public final BasicBlock[] blocklist;  // blocks in breadhth-first order
+	public final BasicBlock[] blocklist;  // blocks in breadth-first order
 	public final VarInfo[] params;        // Parameters and initial values of stack variables
 	public final VarInfo[][] vars;        // Each variable
 	public final UpvalInfo[] upvals;      // from outer scope
@@ -49,7 +49,6 @@ public class ProtoInfo {
 		for ( int slot=0; slot<p.maxstacksize; slot++ ) {
 			VarInfo v = VarInfo.PARAM(slot);
 			params[slot] = v;
-			this.blocklist[0].mergeSlotInput(slot, v);
 		}
 		
 		// find variables
@@ -74,17 +73,13 @@ public class ProtoInfo {
 		// basic blocks
 		for ( int i=0; i<blocklist.length; i++ ) {
 			sb.append( "  block "+blocklist[i].toString() );
-			sb.append( "\n" );
+			appendOpenUps( sb, -1 );
 			
 			// instructions
 			for ( int pc=blocklist[i].pc0; pc<=blocklist[i].pc1; pc++ ) {
 
 				// open upvalue storage
-				for ( int j=0; j<prototype.maxstacksize; j++ ) {
-					if ( vars[j][pc].pc == pc && vars[j][pc].allocupvalue ) {
-						sb.append( "    open: "+vars[j][pc].upvalue+"\n" );
-					}
-				}
+				appendOpenUps( sb, pc );
 				
 				// opcode
 				sb.append( "     " );
@@ -117,6 +112,15 @@ public class ProtoInfo {
 		return sb.toString();
 	}
 
+	private void appendOpenUps(StringBuffer sb, int pc) {
+		for ( int j=0; j<prototype.maxstacksize; j++ ) {
+			VarInfo v = (pc<0? params[j]: vars[j][pc]);
+			if ( v.pc == pc && v.allocupvalue ) {
+				sb.append( "    open: "+v.upvalue+"\n" );
+			}
+		}
+	}
+
 	private VarInfo[][] findVariables() {
 		
 		// create storage for variables.
@@ -385,10 +389,6 @@ public class ProtoInfo {
 	private void substituteVariable(int slot, VarInfo vold, VarInfo vnew) {
 		for ( int i=0, n=prototype.code.length; i<n; i++ )
 			replaceAll( vars[slot], vars[slot].length, vold, vnew );
-		for ( int i=0; i<blocklist.length; i++ ) {
-			BasicBlock b = blocklist[i];
-			replaceAll( b.inputs[slot], b.ninputs[slot], vold, vnew );
-		}
 	}
 
 	private void replaceAll(VarInfo[] v, int n, VarInfo vold, VarInfo vnew) {
@@ -429,7 +429,11 @@ public class ProtoInfo {
 			openups[slot] = new UpvalInfo[prototype.code.length];
 		if ( openups[slot][pc] != null )
 			return openups[slot][pc];
-		return new UpvalInfo(this, pc, slot);
+		UpvalInfo u = new UpvalInfo(this, pc, slot);
+		for ( int i=0, n=prototype.code.length; i<n; ++i )
+			if ( vars[slot][i] != null && vars[slot][i].upvalue == u )
+				openups[slot][i] = u;
+		return u;
 	}
 
 	public boolean isUpvalueAssign(int pc, int slot) {
diff --git a/src/jse/org/luaj/vm2/luajc/UpvalInfo.java b/src/jse/org/luaj/vm2/luajc/UpvalInfo.java
index fc29bd66..6c6f432e 100644
--- a/src/jse/org/luaj/vm2/luajc/UpvalInfo.java
+++ b/src/jse/org/luaj/vm2/luajc/UpvalInfo.java
@@ -69,9 +69,9 @@ public class UpvalInfo {
 			
 			// look for loops
 			if ( v.upvalue == this ) {
-				for ( int i=0, n=b.ninputs[slot]; i<n; i++ ) {
-					v = b.inputs[slot][i];
-					if ( v.upvalue != this )
+				for ( int i=0, n=b.prev!=null? b.prev.length: 0; i<n; i++ ) {
+					v = pi.vars[slot][b.prev[i].pc1];
+					if ( v != null && v.upvalue != this )
 						includeVars(v);
 				}
 				return;
@@ -80,7 +80,7 @@ public class UpvalInfo {
 			// assign the variable
 			v.upvalue = this;
 			this.includeVar(v);
-
+			
 			// nil values also terminate
 			if ( v.pc == -1 )
 				return;
@@ -106,11 +106,17 @@ public class UpvalInfo {
 		BasicBlock b = pi.blocks[v.pc];
 		if ( v.pc > b.pc0 )
 			return pi.vars[slot][v.pc-1].upvalue != this;
-		if ( b.ninputs[slot] <= 0 )
-			return true;
-		for ( int k=0, n=b.ninputs[slot]; k<n; k++ )
-			if ( b.inputs[slot][k].upvalue != this )
+		if ( b.prev == null ) {
+			v = pi.params[slot];
+			if ( v != null && v.upvalue != this )
 				return true;
+		} else {
+			for ( int i=0, n=b.prev.length; i<n; i++ ) {
+				v = pi.vars[slot][b.prev[i].pc1];
+				if ( v != null && v.upvalue != this )
+					return true;
+			}
+		}
 		return false;
 	}