From c1f67181fa3c7159b31da5ed1591e5b33c1610a2 Mon Sep 17 00:00:00 2001
From: James Roseborough <james.roseborough@luaj.org>
Date: Sat, 24 Apr 2010 17:18:52 +0000
Subject: [PATCH] Improve bytecode generation.

---
 src/jse/org/luaj/vm2/luajc/JavaBuilder.java | 28 ++++++++++++++-------
 src/jse/org/luaj/vm2/luajc/JavaGen.java     |  3 ++-
 src/jse/org/luaj/vm2/luajc/Slots.java       |  2 +-
 test/junit/org/luaj/vm2/FragmentsTest.java  |  7 +++++-
 4 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/src/jse/org/luaj/vm2/luajc/JavaBuilder.java b/src/jse/org/luaj/vm2/luajc/JavaBuilder.java
index bf5aec8c..9f9a3e82 100644
--- a/src/jse/org/luaj/vm2/luajc/JavaBuilder.java
+++ b/src/jse/org/luaj/vm2/luajc/JavaBuilder.java
@@ -574,16 +574,26 @@ public class JavaBuilder {
 	private Map<LuaValue,String> constants = new HashMap<LuaValue,String>();
 	
 	public void loadConstant(LuaValue value) {
-		String name = constants.get(value);
-		if ( name == null ) {
-			name = value.type() == LuaValue.TNUMBER? 
-					value.isinttype()? 
-						createLuaIntegerField(value.checkint()):
-						createLuaDoubleField(value.checkdouble()):
-					createLuaStringField(value.checkstring());
-			constants.put(value, name);
+		switch ( value.type() ) {
+		case LuaValue.TNIL: 
+			loadNil();
+			break;
+		case LuaValue.TNUMBER:
+		case LuaValue.TSTRING:
+			String name = constants.get(value);
+			if ( name == null ) {
+				name = value.type() == LuaValue.TNUMBER? 
+						value.isinttype()? 
+							createLuaIntegerField(value.checkint()):
+							createLuaDoubleField(value.checkdouble()):
+						createLuaStringField(value.checkstring());
+				constants.put(value, name);
+			}
+			append(factory.createGetStatic(classname, name, TYPE_LUAVALUE));
+			break;
+		default:
+			throw new IllegalArgumentException("bad constant type: "+value.type());
 		}
-		append(factory.createGetStatic(classname, name, TYPE_LUAVALUE));
 	}
 
 	private String createLuaIntegerField(int value) {
diff --git a/src/jse/org/luaj/vm2/luajc/JavaGen.java b/src/jse/org/luaj/vm2/luajc/JavaGen.java
index 95ef1b7a..ce382077 100644
--- a/src/jse/org/luaj/vm2/luajc/JavaGen.java
+++ b/src/jse/org/luaj/vm2/luajc/JavaGen.java
@@ -172,7 +172,8 @@ public class JavaGen {
 			case Lua.OP_LOADBOOL:/*	A B C	R(A):= (Bool)B: if (C) pc++			*/
 				builder.loadBoolean( b!=0 );
 				builder.storeLocal( pc, a );
-				//if ( c != 0 ) branchdest[index+2] = true;
+				if ( c!=0 ) 
+					builder.addBranch(pc, JavaBuilder.BRANCH_GOTO, pc+2);
 				break;
 				
 			case Lua.OP_JMP: /*	sBx	pc+=sBx					*/
diff --git a/src/jse/org/luaj/vm2/luajc/Slots.java b/src/jse/org/luaj/vm2/luajc/Slots.java
index d0411696..f4f2f25a 100644
--- a/src/jse/org/luaj/vm2/luajc/Slots.java
+++ b/src/jse/org/luaj/vm2/luajc/Slots.java
@@ -383,7 +383,7 @@ public class Slots {
 	private int prevUndefined(int index, int j) {
 		for ( ; index>=0; --index )
 			if ( ((slots[index][j] & BIT_INVALID) != 0) )
-				return 0;
+				return index;
 		return index;
 	}
 
diff --git a/test/junit/org/luaj/vm2/FragmentsTest.java b/test/junit/org/luaj/vm2/FragmentsTest.java
index d6c6885f..26a8eda2 100644
--- a/test/junit/org/luaj/vm2/FragmentsTest.java
+++ b/test/junit/org/luaj/vm2/FragmentsTest.java
@@ -333,5 +333,10 @@ public class FragmentsTest extends TestCase {
 				"end\n" +
 				"return foo()\n" );				
 	}
-	
+	public void testTestSimpleBinops() {
+		runFragment( LuaValue.varargsOf(new LuaValue[] {
+				LuaValue.FALSE, LuaValue.FALSE, LuaValue.TRUE, LuaValue.TRUE, LuaValue.FALSE }),
+				"local a,b,c = 2,-2.5,0\n" +
+				"return (a==c), (b==c), (a==a), (a>c), (b>0)\n" );
+	}
 }