X-Git-Url: https://gerrit.simantics.org/r/gitweb?p=simantics%2Fplatform.git;a=blobdiff_plain;f=bundles%2Forg.simantics.scl.compiler%2Fsrc%2Forg%2Fsimantics%2Fscl%2Fcompiler%2Finternal%2Fcodegen%2Fssa%2Fstatements%2FLetApply.java;h=400cb6e4e373f78c480e8fc37c1da3dc203a47f2;hp=83b1e0cb67a81afe13249ace83f230097b2ed892;hb=fad36d463b75c3a9944d875fc627c3533f6da74d;hpb=3303fe4a3b363e88662ac75a4f7e873ddb3ab352

diff --git a/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/internal/codegen/ssa/statements/LetApply.java b/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/internal/codegen/ssa/statements/LetApply.java
index 83b1e0cb6..400cb6e4e 100644
--- a/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/internal/codegen/ssa/statements/LetApply.java
+++ b/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/internal/codegen/ssa/statements/LetApply.java
@@ -1,462 +1,491 @@
-package org.simantics.scl.compiler.internal.codegen.ssa.statements;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-
-import org.simantics.scl.compiler.common.exceptions.InternalCompilerError;
-import org.simantics.scl.compiler.constants.Constant;
-import org.simantics.scl.compiler.internal.codegen.continuations.ContRef;
-import org.simantics.scl.compiler.internal.codegen.references.BoundVar;
-import org.simantics.scl.compiler.internal.codegen.references.Val;
-import org.simantics.scl.compiler.internal.codegen.references.ValRef;
-import org.simantics.scl.compiler.internal.codegen.ssa.SSABlock;
-import org.simantics.scl.compiler.internal.codegen.ssa.SSAExit;
-import org.simantics.scl.compiler.internal.codegen.ssa.SSAFunction;
-import org.simantics.scl.compiler.internal.codegen.ssa.SSAStatement;
-import org.simantics.scl.compiler.internal.codegen.ssa.binders.BoundVarBinder;
-import org.simantics.scl.compiler.internal.codegen.ssa.binders.ValRefBinder;
-import org.simantics.scl.compiler.internal.codegen.ssa.exits.Jump;
-import org.simantics.scl.compiler.internal.codegen.ssa.exits.Switch;
-import org.simantics.scl.compiler.internal.codegen.utils.CopyContext;
-import org.simantics.scl.compiler.internal.codegen.utils.MethodBuilder;
-import org.simantics.scl.compiler.internal.codegen.utils.PrintingContext;
-import org.simantics.scl.compiler.internal.codegen.utils.SSASimplificationContext;
-import org.simantics.scl.compiler.internal.codegen.utils.SSAValidationContext;
-import org.simantics.scl.compiler.top.SCLCompilerConfiguration;
-import org.simantics.scl.compiler.types.TVar;
-import org.simantics.scl.compiler.types.Type;
-import org.simantics.scl.compiler.types.Types;
-import org.simantics.scl.compiler.types.exceptions.MatchException;
-import org.simantics.scl.compiler.types.util.MultiFunction;
-
-public class LetApply extends LetStatement implements ValRefBinder {
-    private ValRef function;
-    private ValRef[] parameters;
-    Type effect;
-    
-    public LetApply(BoundVar target, Type effect, ValRef function, ValRef ... parameters) {
-        super(target);
-        if(SCLCompilerConfiguration.DEBUG) {
-            if(effect == null)
-                throw new InternalCompilerError();
-            if(function.getBinding() == null)
-                throw new InternalCompilerError();
-        }
-        this.setFunction(function);
-        this.setParameters(parameters);
-        this.effect = Types.canonical(effect);
-    }
-
-    public void push(MethodBuilder mb) {
-        //mb.getCodeBuilder().mapLineNumber(lineNumber);
-        Val f = getFunction().getBinding();
-        Val[] ps = ValRef.getBindings(getParameters());
-        if(f instanceof Constant) {
-            Constant cf = (Constant)f;
-            Type returnType = cf.apply(mb, getFunction().getTypeParameters(), ps);
-            if(Types.isBoxed(returnType))
-                mb.unbox(target.getType());
-        }
-        else {            
-            mb.push(f, f.getType());
-            mb.pushBoxed(ps);
-            mb.genericApply(ps.length);
-            mb.unbox(target.getType());
-        }
-    }
-    
-    @Override
-    public void generateCode(MethodBuilder mb) {
-        if(!target.generateOnFly) {
-            push(mb);
-            mb.store(target);
-        }
-    }
-
-    @Override
-    public void toString(PrintingContext context) {
-        if(determineGenerateOnFly())
-            context.addInlineExpression(target, this);
-        else
-            toStringAux(context);
-    }
-    
-    private void toStringAux(PrintingContext context) {
-        context.indentation();
-        context.append(target);
-        context.append("(" + target.occurrenceCount() + ")");
-        context.append(" = ");
-        bodyToString(context);
-        context.append('\n');
-        
-    }
-    
-    public void bodyToString(PrintingContext context) {
-        if(context.getErrorMarker() == this)
-            context.append("!> ");
-        if(hasEffect()) {
-            context.append("<");
-            context.append(effect);
-            context.append("> ");
-        }
-        context.append(getFunction());
-        for(ValRef parameter : getParameters()) {
-            context.append(' ');
-            context.append(parameter);
-        }
-    }
-    
-    @Override
-    public String toString() {
-        PrintingContext context = new PrintingContext();
-        toStringAux(context);
-        return context.toString();
-    }
-
-    @Override
-    public void validate(SSAValidationContext context) {
-        context.validate(target);
-        if(target.getParent() != this)
-            throw new InternalCompilerError();
-        context.validate(function);
-        if(function.getParent() != this)
-            throw new InternalCompilerError();
-        for(ValRef parameter : parameters) {
-            context.validate(parameter);
-            if(parameter.getParent() != this)
-                throw new InternalCompilerError();
-        }
-        //if(parameters.length == 0)
-        //    throw new InternalCompilerError();
-        
-        
-        MultiFunction mFun;
-        try {
-            mFun = Types.matchFunction(getFunction().getType(), getParameters().length);
-        } catch (MatchException e) {
-            context.setErrorMarker(this);
-            throw new InternalCompilerError();
-        }
-        for(int i=0;i<getParameters().length;++i)
-            context.assertSubsumes(this, getParameters()[i].getType(), mFun.parameterTypes[i]);
-        context.assertSubsumes(this, target.getType(), mFun.returnType);
-        context.assertEqualsEffect(this, effect, mFun.effect);
-    }
-
-    @Override
-    public void destroy() {
-        getFunction().remove();
-        for(ValRef parameter : getParameters())
-            parameter.remove();
-    }
-    
-    @Override
-    public void simplify(SSASimplificationContext context) {
-        if(target.hasNoOccurences() && !hasEffect()) {
-            remove();
-            context.markModified("LetApply.dead-let-statement");
-            return;
-        }
-        Val functionVal = getFunction().getBinding();
-        if(functionVal instanceof BoundVar) {
-            BoundVarBinder parent_ = ((BoundVar)functionVal).parent;
-            if(parent_ instanceof SSAFunction) {
-                SSAFunction function = (SSAFunction)parent_;
-                if(functionVal.hasMoreThanOneOccurences())
-                    return;
-                if(getParameters().length < function.getArity())
-                    return;
-                if(getParameters().length > function.getArity())
-                    split(function.getArity());
-                inline(function);
-                function.detach();
-                context.markModified("LetApply.beta-lambda");
-            }
-            else if(parent_ instanceof LetApply) {
-                LetApply apply = (LetApply)parent_;
-                if(apply.hasEffect())
-                    return;
-                boolean hasJustOneOccurence = !functionVal.hasMoreThanOneOccurences();
-                if((hasJustOneOccurence && apply.getParent() == getParent()) ||
-                        apply.isPartial()) {
-                    if(hasJustOneOccurence) {
-                        apply.detach();
-                        setFunction(apply.getFunction());
-                        setParameters(ValRef.concat(apply.getParameters(), getParameters()));
-                    }
-                    else {
-                        setFunction(apply.getFunction().copy());
-                        setParameters(ValRef.concat(ValRef.copy(apply.getParameters()), getParameters()));
-                    }
-                    context.markModified("LetApply.merge-applications");
-                }
-            }
-            else if(parent_ instanceof SSABlock) {
-                SSABlock parent = getParent();
-                if(parent_ != parent)
-                    return;
-                if(parent.getFirstStatement() != this)
-                    return;
-                if(!parent.hasMoreThanOneOccurences())
-                    return; // We stop here, because situation can be handled by better transformations
-                if(functionVal.hasMoreThanOneOccurences())
-                    return;
-                // We have now the following situation:
-                //    [c] ... f ... =
-                //        x = f ... 
-                // * this application is the only reference to f
-                // * there are multiple references to [c]
-                for(ContRef ref = parent.getOccurrence();ref != null; ref = ref.getNext())
-                    if(!(ref.getParent() instanceof Jump))
-                        return;
-                
-                // Finds the position of the functionVal in the parameter list of 
-                // the parent block.
-                int position;
-                for(position=0;position<parent.getParameters().length;++position)
-                    if(parent.getParameters()[position] == functionVal)
-                        break;
-                if(position == parent.getParameters().length)
-                    throw new InternalCompilerError();
-                
-                // Do tranformation
-                for(ContRef ref = parent.getOccurrence();ref != null; ref = ref.getNext()) {
-                    Jump jump = (Jump)ref.getParent();
-                    SSABlock block = jump.getParent();
-                    
-                    BoundVar newTarget = new BoundVar(target.getType());
-                    block.addStatement(new LetApply(newTarget, effect, jump.getParameter(position), ValRef.copy(parameters)));
-                    jump.setParameter(position, newTarget.createOccurrence());
-                }
-                
-                parent.setParameter(position, target);
-                remove();
-                context.markModified("LetApply.hoist-apply");
-            }
-        }
-        else if(functionVal instanceof Constant) {
-            ((Constant)functionVal).inline(context, this);
-        }
-    }
-    
-    public boolean isPartial() {
-        return parameters.length < function.getBinding().getEffectiveArity();
-    }
-
-    /**
-     * Removes apply if it does not have parameters.
-     */
-    public void removeDegenerated() {
-        if(getParameters().length == 0) {
-            target.replaceBy(getFunction());
-            getFunction().remove();
-            detach();
-        }
-    }
-
-    public boolean determineGenerateOnFly() {
-        if(hasEffect())
-            return false;
-        ValRef ref = target.getOccurrence();
-        if(ref == null || ref.getNext() != null)
-            return false;
-        Object parent = ref.getParent();
-        if(parent instanceof SSAStatement) {
-            if(((SSAStatement)parent).getParent() != getParent())
-                return false;
-        }
-        else if(parent instanceof SSAExit) {
-            if(((SSAExit)parent).getParent() != getParent())
-                return false;
-            if(parent instanceof Switch)
-                return false;
-        }
-        else
-            return false;
-        return true;
-    }
-    
-    @Override
-    public void markGenerateOnFly() {        
-        target.generateOnFly = determineGenerateOnFly();
-    }
-
-    public ValRef getFunction() {
-        return function;
-    }
-
-    public void setFunction(ValRef function) {
-        this.function = function;
-        function.setParent(this);
-    }
-
-    public ValRef[] getParameters() {
-        return parameters;
-    }
-
-    public void setParameters(ValRef[] parameters) {
-        /*if(SCLCompilerConfiguration.DEBUG)
-            if(parameters.length == 0)
-                throw new InternalCompilerError();*/
-        this.parameters = parameters;
-        for(ValRef parameter : parameters)
-            parameter.setParent(this);
-    }
-    
-    @Override
-    public SSAStatement copy(CopyContext context) {
-        LetApply result = new LetApply(context.copy(target), 
-                context.copyType(effect),
-                context.copy(function), 
-                context.copy(parameters));
-        return result;
-    }
-    
-    @Override
-    public void replace(TVar[] vars, Type[] replacements) {
-        target.replace(vars, replacements);
-        function.replace(vars, replacements);
-        effect = effect.replace(vars, replacements);
-        for(ValRef parameter : parameters)
-            parameter.replace(vars, replacements);
-    }
-    
-    /**
-     * Inlines the application by the given function.
-     * It is assumed that the function has the same number
-     * of parameters as this one and there are no other 
-     * references to the function (copy function before
-     * inlining if necessary).
-     */
-    public void inline(SSAFunction function) {
-        if(function.getArity() != parameters.length)
-            throw new InternalCompilerError();        
-               
-        SSABlock headBlock = getParent();
-        SSAFunction thisFunction = headBlock.getParent();
-               
-        /*System.out.println("--- INLINING -------------------------------");
-        System.out.println(thisFunction);
-        System.out.println("Function name: " + getFunction().getBinding());
-        System.out.println("++++++++++++++++++++++++++++++++++++++++++++");
-        System.out.println(function);   
-        */
-        
-        if(this.function.getTypeParameters().length > 0) {
-            /*if(function.getParent() != null) {
-                PrintingContext pc = new PrintingContext();
-                pc.append("----------------------------\n");
-                function.getParent().getParentFunction().toString(pc);
-                pc.append("\n----\n");
-                function.toString(pc);
-                pc.append("\n");
-                pc.append(function.getTypeParameters());
-                pc.append(" -> ");
-                pc.append(this.function.getTypeParameters());
-                System.out.println(pc.toString());
-            }*/
-            function.replace(function.getTypeParameters(), this.function.getTypeParameters());
-        }
-
-        if(getPrev() != null)
-            getPrev().setAsLastStatement();
-        else
-            headBlock.removeStatements();
-        
-        // Create tail block
-        SSABlock tailBlock = new SSABlock(new BoundVar[] {target});
-        thisFunction.addBlock(tailBlock);
-        {
-            SSAStatement stat = getNext();
-            while(stat != null) {
-                SSAStatement temp = stat.getNext();
-                tailBlock.addStatement(stat);
-                stat = temp;
-            }
-        }
-        tailBlock.setExit(headBlock.getExit());
-        
-        // Merge blocks        
-        thisFunction.mergeBlocks(function);           
-        
-        headBlock.setExit(new Jump(function.getFirstBlock().createOccurrence(), 
-                parameters));
-        function.getReturnCont().replaceWith(tailBlock);
-
-        this.function.remove();
-        // Note: No need to remove or detach this statement anymore
-        
-        // TODO remove function
-        /*
-        System.out.println("============================================");
-        System.out.println(thisFunction);
-        */
-    }
-
-    @Override
-    public void collectFreeVariables(SSAFunction parentFunction,
-            ArrayList<ValRef> vars) {
-        function.collectFreeVariables(parentFunction, vars);
-        for(ValRef parameter : parameters)
-            parameter.collectFreeVariables(parentFunction, vars);
-    }
-    
-    @Override
-    public void replaceByApply(ValRef valRef, Val newFunction, Type[] typeParameters, Val[] parameters) {
-        if(function == valRef) {
-            valRef.remove();
-            setFunction(newFunction.createOccurrence(typeParameters));
-            setParameters(ValRef.concat(ValRef.createOccurrences(parameters), this.parameters));
-        }
-        else
-            super.replaceByApply(valRef, newFunction, typeParameters, parameters);
-    }
-
-    /**
-     * Splits this application into two applications where the first has
-     * the arity given as a parameter and the new application inserted 
-     * after this statement has the rest of the parameters.
-     */
-    public void split(int arity) {
-        if(arity == parameters.length)
-            return;
-        if(arity > parameters.length)
-            throw new InternalCompilerError();
-        ValRef[] firstHalf = arity == 0 ? ValRef.EMPTY_ARRAY : Arrays.copyOf(parameters, arity);
-        ValRef[] secondHalf = arity == parameters.length ? ValRef.EMPTY_ARRAY : Arrays.copyOfRange(parameters, arity, parameters.length);
-        BoundVar newVar;
-        try {
-            MultiFunction mfun = Types.matchFunction(function.getType(), arity);
-            newVar = new BoundVar(mfun.returnType);
-        } catch (MatchException e) {
-            throw new InternalCompilerError();
-        }
-        LetApply newApply = new LetApply(target, effect, 
-                newVar.createOccurrence(), secondHalf);
-        newApply.insertAfter(this);
-        effect = Types.NO_EFFECTS;
-        setTarget(newVar);
-        setParameters(firstHalf);
-    }
-    
-    /**
-     * True, if the application may have side effects.
-     */
-    public boolean hasEffect() {
-        return effect != Types.NO_EFFECTS;
-    }
-
-    public void updateEffect() {
-        try {
-            MultiFunction mFun = Types.matchFunction(function.getType(), parameters.length);
-            this.effect = mFun.effect;
-        } catch (MatchException e) {
-            throw new InternalCompilerError(e);
-        }
-    }
-    
-    @Override
-    public void prepare(MethodBuilder mb) {
-        function.getBinding().prepare(mb);
-    }
-}
+package org.simantics.scl.compiler.internal.codegen.ssa.statements;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+
+import org.simantics.scl.compiler.common.exceptions.InternalCompilerError;
+import org.simantics.scl.compiler.constants.Constant;
+import org.simantics.scl.compiler.constants.SCLConstant;
+import org.simantics.scl.compiler.internal.codegen.continuations.ContRef;
+import org.simantics.scl.compiler.internal.codegen.references.BoundVar;
+import org.simantics.scl.compiler.internal.codegen.references.Val;
+import org.simantics.scl.compiler.internal.codegen.references.ValRef;
+import org.simantics.scl.compiler.internal.codegen.ssa.SSABlock;
+import org.simantics.scl.compiler.internal.codegen.ssa.SSAExit;
+import org.simantics.scl.compiler.internal.codegen.ssa.SSAFunction;
+import org.simantics.scl.compiler.internal.codegen.ssa.SSAStatement;
+import org.simantics.scl.compiler.internal.codegen.ssa.binders.BoundVarBinder;
+import org.simantics.scl.compiler.internal.codegen.ssa.binders.ValRefBinder;
+import org.simantics.scl.compiler.internal.codegen.ssa.exits.Jump;
+import org.simantics.scl.compiler.internal.codegen.ssa.exits.Switch;
+import org.simantics.scl.compiler.internal.codegen.utils.CopyContext;
+import org.simantics.scl.compiler.internal.codegen.utils.MethodBuilder;
+import org.simantics.scl.compiler.internal.codegen.utils.PrintingContext;
+import org.simantics.scl.compiler.internal.codegen.utils.SSASimplificationContext;
+import org.simantics.scl.compiler.internal.codegen.utils.SSAValidationContext;
+import org.simantics.scl.compiler.internal.codegen.utils.ValRefVisitor;
+import org.simantics.scl.compiler.top.SCLCompilerConfiguration;
+import org.simantics.scl.compiler.types.TVar;
+import org.simantics.scl.compiler.types.Type;
+import org.simantics.scl.compiler.types.Types;
+import org.simantics.scl.compiler.types.exceptions.MatchException;
+import org.simantics.scl.compiler.types.util.MultiFunction;
+
+public class LetApply extends LetStatement implements ValRefBinder {
+    private ValRef function;
+    private ValRef[] parameters;
+    Type effect;
+    
+    public LetApply(BoundVar target, Type effect, ValRef function, ValRef ... parameters) {
+        super(target);
+        if(SCLCompilerConfiguration.DEBUG) {
+            if(effect == null)
+                throw new InternalCompilerError();
+            if(function.getBinding() == null)
+                throw new InternalCompilerError();
+        }
+        this.setFunction(function);
+        this.setParameters(parameters);
+        this.effect = Types.canonical(effect);
+    }
+
+    public void push(MethodBuilder mb) {
+        //mb.getCodeBuilder().mapLineNumber(lineNumber);
+        Val f = getFunction().getBinding();
+        Val[] ps = ValRef.getBindings(getParameters());
+        if(f instanceof Constant) {
+            Constant cf = (Constant)f;
+            Type returnType = cf.apply(mb, getFunction().getTypeParameters(), ps);
+            if(Types.isBoxed(returnType))
+                mb.unbox(target.getType());
+        }
+        else {            
+            mb.push(f, f.getType());
+            mb.pushBoxed(ps);
+            mb.genericApply(ps.length);
+            mb.unbox(target.getType());
+        }
+    }
+    
+    @Override
+    public void generateCode(MethodBuilder mb) {
+        if(!target.generateOnFly) {
+            push(mb);
+            mb.store(target);
+        }
+    }
+
+    @Override
+    public void toString(PrintingContext context) {
+        if(/*target.getLabel() == null &&*/ determineGenerateOnFly())
+            context.addInlineExpression(target, this);
+        else
+            toStringAux(context);
+    }
+    
+    private void toStringAux(PrintingContext context) {
+        context.indentation();
+        context.append(target);
+        context.append("(" + target.occurrenceCount() + ")");
+        context.append(" = ");
+        bodyToString(context);
+        context.append('\n');
+        
+    }
+    
+    public void bodyToString(PrintingContext context) {
+        if(context.getErrorMarker() == this)
+            context.append("!> ");
+        if(hasEffect()) {
+            context.append("<");
+            context.append(effect);
+            context.append("> ");
+        }
+        context.append(getFunction());
+        for(ValRef parameter : getParameters()) {
+            context.append(' ');
+            context.append(parameter);
+        }
+    }
+    
+    @Override
+    public String toString() {
+        PrintingContext context = new PrintingContext();
+        toStringAux(context);
+        return context.toString();
+    }
+
+    @Override
+    public void validate(SSAValidationContext context) {
+        context.validate(target);
+        if(target.getParent() != this)
+            throw new InternalCompilerError();
+        context.validate(function);
+        if(function.getParent() != this)
+            throw new InternalCompilerError();
+        for(ValRef parameter : parameters) {
+            context.validate(parameter);
+            if(parameter.getParent() != this)
+                throw new InternalCompilerError();
+        }
+        //if(parameters.length == 0)
+        //    throw new InternalCompilerError();
+        
+        
+        MultiFunction mFun;
+        try {
+            mFun = Types.matchFunction(getFunction().getType(), getParameters().length);
+        } catch (MatchException e) {
+            context.setErrorMarker(this);
+            throw new InternalCompilerError();
+        }
+        for(int i=0;i<getParameters().length;++i)
+            context.assertSubsumes(this, getParameters()[i].getType(), mFun.parameterTypes[i]);
+        context.assertSubsumes(this, target.getType(), mFun.returnType);
+        context.assertEqualsEffect(this, effect, mFun.effect);
+    }
+
+    @Override
+    public void destroy() {
+        getFunction().remove();
+        for(ValRef parameter : getParameters())
+            parameter.remove();
+    }
+    
+    @Override
+    public void simplify(SSASimplificationContext context) {
+        if(target.hasNoOccurences() && !hasEffect()) {
+            remove();
+            context.markModified("LetApply.dead-let-statement");
+            return;
+        }
+        // TODO this is quite heavy way for inlining constants
+        for(int i=0;i<parameters.length;++i) {
+            ValRef parameter = parameters[i];
+            Val value = parameter.getBinding();
+            if(!(value instanceof SCLConstant))
+                continue;
+            SCLConstant constant = (SCLConstant)value;
+            if(constant.inlineArity != 0)
+                continue;
+            SSAFunction definition = constant.definition;
+            SSABlock block = definition.getFirstBlock();
+            if(block.getFirstStatement() != null || !(block.getExit() instanceof Jump))
+                continue;
+            Jump jump = (Jump)block.getExit();
+            if(jump.getTarget().getBinding() != definition.getReturnCont())
+                continue;
+            if(jump.getParameter(0).getTypeParameters().length > 0)
+                continue;
+            parameter.replaceBy(jump.getParameter(0).getBinding());
+        }
+        Val functionVal = getFunction().getBinding();
+        if(functionVal instanceof BoundVar) {
+            BoundVarBinder parent_ = ((BoundVar)functionVal).parent;
+            if(parent_ instanceof SSAFunction) {
+                SSAFunction function = (SSAFunction)parent_;
+                if(functionVal.hasMoreThanOneOccurences())
+                    return;
+                if(getParameters().length < function.getArity())
+                    return;
+                if(getParameters().length > function.getArity())
+                    split(function.getArity());
+                inline(function);
+                function.detach();
+                context.markModified("LetApply.beta-lambda");
+            }
+            else if(parent_ instanceof LetApply) {
+                LetApply apply = (LetApply)parent_;
+                if(apply.hasEffect())
+                    return;
+                boolean hasJustOneOccurence = !functionVal.hasMoreThanOneOccurences();
+                if((hasJustOneOccurence && apply.getParent() == getParent()) ||
+                        apply.isPartial()) {
+                    if(hasJustOneOccurence) {
+                        apply.detach();
+                        setFunction(apply.getFunction());
+                        setParameters(ValRef.concat(apply.getParameters(), getParameters()));
+                    }
+                    else {
+                        setFunction(apply.getFunction().copy());
+                        setParameters(ValRef.concat(ValRef.copy(apply.getParameters()), getParameters()));
+                    }
+                    context.markModified("LetApply.merge-applications");
+                }
+            }
+            else if(parent_ instanceof SSABlock) {
+                SSABlock parent = getParent();
+                if(parent_ != parent)
+                    return;
+                if(parent.getFirstStatement() != this)
+                    return;
+                if(!parent.hasMoreThanOneOccurences())
+                    return; // We stop here, because situation can be handled by better transformations
+                if(functionVal.hasMoreThanOneOccurences())
+                    return;
+                // We have now the following situation:
+                //    [c] ... f ... =
+                //        x = f ... 
+                // * this application is the only reference to f
+                // * there are multiple references to [c]
+                for(ContRef ref = parent.getOccurrence();ref != null; ref = ref.getNext())
+                    if(!(ref.getParent() instanceof Jump))
+                        return;
+                
+                // Finds the position of the functionVal in the parameter list of 
+                // the parent block.
+                int position;
+                for(position=0;position<parent.getParameters().length;++position)
+                    if(parent.getParameters()[position] == functionVal)
+                        break;
+                if(position == parent.getParameters().length)
+                    throw new InternalCompilerError();
+                
+                // Do tranformation
+                for(ContRef ref = parent.getOccurrence();ref != null; ref = ref.getNext()) {
+                    Jump jump = (Jump)ref.getParent();
+                    SSABlock block = jump.getParent();
+                    
+                    BoundVar newTarget = new BoundVar(target.getType());
+                    block.addStatement(new LetApply(newTarget, effect, jump.getParameter(position), ValRef.copy(parameters)));
+                    jump.setParameter(position, newTarget.createOccurrence());
+                }
+                
+                parent.setParameter(position, target);
+                remove();
+                context.markModified("LetApply.hoist-apply");
+            }
+        }
+        else if(functionVal instanceof Constant) {
+            ((Constant)functionVal).inline(context, this);
+        }
+    }
+    
+    public boolean isPartial() {
+        return parameters.length < function.getBinding().getEffectiveArity();
+    }
+
+    /**
+     * Removes apply if it does not have parameters.
+     */
+    public void removeDegenerated() {
+        if(getParameters().length == 0) {
+            target.replaceBy(getFunction());
+            getFunction().remove();
+            detach();
+        }
+    }
+
+    public boolean determineGenerateOnFly() {
+        if(hasEffect())
+            return false;
+        ValRef ref = target.getOccurrence();
+        if(ref == null || ref.getNext() != null)
+            return false;
+        Object parent = ref.getParent();
+        if(parent instanceof SSAStatement) {
+            if(((SSAStatement)parent).getParent() != getParent())
+                return false;
+        }
+        else if(parent instanceof SSAExit) {
+            if(((SSAExit)parent).getParent() != getParent())
+                return false;
+            if(parent instanceof Switch)
+                return false;
+        }
+        else
+            return false;
+        return true;
+    }
+    
+    @Override
+    public void markGenerateOnFly() {        
+        target.generateOnFly = determineGenerateOnFly();
+    }
+
+    public ValRef getFunction() {
+        return function;
+    }
+
+    public void setFunction(ValRef function) {
+        this.function = function;
+        function.setParent(this);
+    }
+
+    public ValRef[] getParameters() {
+        return parameters;
+    }
+
+    public void setParameters(ValRef[] parameters) {
+        /*if(SCLCompilerConfiguration.DEBUG)
+            if(parameters.length == 0)
+                throw new InternalCompilerError();*/
+        this.parameters = parameters;
+        for(ValRef parameter : parameters)
+            parameter.setParent(this);
+    }
+    
+    @Override
+    public SSAStatement copy(CopyContext context) {
+        LetApply result = new LetApply(context.copy(target), 
+                context.copyType(effect),
+                context.copy(function), 
+                context.copy(parameters));
+        return result;
+    }
+    
+    @Override
+    public void replace(TVar[] vars, Type[] replacements) {
+        target.replace(vars, replacements);
+        function.replace(vars, replacements);
+        effect = effect.replace(vars, replacements);
+        for(ValRef parameter : parameters)
+            parameter.replace(vars, replacements);
+    }
+    
+    /**
+     * Inlines the application by the given function.
+     * It is assumed that the function has the same number
+     * of parameters as this one and there are no other 
+     * references to the function (copy function before
+     * inlining if necessary).
+     */
+    public void inline(SSAFunction function) {
+        if(function.getArity() != parameters.length)
+            throw new InternalCompilerError();        
+               
+        SSABlock headBlock = getParent();
+        SSAFunction thisFunction = headBlock.getParent();
+               
+        /*System.out.println("--- INLINING -------------------------------");
+        System.out.println(thisFunction);
+        System.out.println("Function name: " + getFunction().getBinding());
+        System.out.println("++++++++++++++++++++++++++++++++++++++++++++");
+        System.out.println(function);   
+        */
+        
+        if(this.function.getTypeParameters().length > 0) {
+            /*if(function.getParent() != null) {
+                PrintingContext pc = new PrintingContext();
+                pc.append("----------------------------\n");
+                function.getParent().getParentFunction().toString(pc);
+                pc.append("\n----\n");
+                function.toString(pc);
+                pc.append("\n");
+                pc.append(function.getTypeParameters());
+                pc.append(" -> ");
+                pc.append(this.function.getTypeParameters());
+                System.out.println(pc.toString());
+            }*/
+            function.replace(function.getTypeParameters(), this.function.getTypeParameters());
+        }
+
+        if(getPrev() != null)
+            getPrev().setAsLastStatement();
+        else
+            headBlock.removeStatements();
+        
+        // Create tail block
+        SSABlock tailBlock = new SSABlock(new BoundVar[] {target});
+        thisFunction.addBlock(tailBlock);
+        {
+            SSAStatement stat = getNext();
+            while(stat != null) {
+                SSAStatement temp = stat.getNext();
+                tailBlock.addStatement(stat);
+                stat = temp;
+            }
+        }
+        tailBlock.setExit(headBlock.getExit());
+        
+        // Merge blocks        
+        thisFunction.mergeBlocks(function);
+        
+        headBlock.setExit(new Jump(function.getFirstBlock().createOccurrence(), 
+                parameters));
+        function.getReturnCont().replaceWith(tailBlock);
+
+        this.function.remove();
+        // Note: No need to remove or detach this statement anymore
+        
+        // TODO remove function
+        /*
+        System.out.println("============================================");
+        System.out.println(thisFunction);
+        */
+    }
+
+    @Override
+    public void collectFreeVariables(SSAFunction parentFunction,
+            ArrayList<ValRef> vars) {
+        function.collectFreeVariables(parentFunction, vars);
+        for(ValRef parameter : parameters)
+            parameter.collectFreeVariables(parentFunction, vars);
+    }
+    
+    @Override
+    public void replaceByApply(ValRef valRef, Val newFunction, Type[] typeParameters, Val[] parameters) {
+        if(function == valRef) {
+            valRef.remove();
+            setFunction(newFunction.createOccurrence(typeParameters));
+            setParameters(ValRef.concat(ValRef.createOccurrences(parameters), this.parameters));
+        }
+        else
+            super.replaceByApply(valRef, newFunction, typeParameters, parameters);
+    }
+
+    /**
+     * Splits this application into two applications where the first has
+     * the arity given as a parameter and the new application inserted 
+     * after this statement has the rest of the parameters.
+     */
+    public void split(int arity) {
+        if(arity == parameters.length)
+            return;
+        if(arity > parameters.length)
+            throw new InternalCompilerError();
+        ValRef[] firstHalf = arity == 0 ? ValRef.EMPTY_ARRAY : Arrays.copyOf(parameters, arity);
+        ValRef[] secondHalf = arity == parameters.length ? ValRef.EMPTY_ARRAY : Arrays.copyOfRange(parameters, arity, parameters.length);
+        BoundVar newVar;
+        try {
+            MultiFunction mfun = Types.matchFunction(function.getType(), arity);
+            newVar = new BoundVar(mfun.returnType);
+        } catch (MatchException e) {
+            throw new InternalCompilerError();
+        }
+        LetApply newApply = new LetApply(target, effect, 
+                newVar.createOccurrence(), secondHalf);
+        newApply.insertAfter(this);
+        effect = Types.NO_EFFECTS;
+        setTarget(newVar);
+        setParameters(firstHalf);
+    }
+    
+    /**
+     * True, if the application may have side effects.
+     */
+    public boolean hasEffect() {
+        return effect != Types.NO_EFFECTS;
+    }
+
+    public void updateEffect() {
+        try {
+            MultiFunction mFun = Types.matchFunction(function.getType(), parameters.length);
+            this.effect = mFun.effect;
+        } catch (MatchException e) {
+            throw new InternalCompilerError(e);
+        }
+    }
+    
+    @Override
+    public void prepare(MethodBuilder mb) {
+        function.getBinding().prepare(mb);
+    }
+
+    @Override
+    public void forValRefs(ValRefVisitor visitor) {
+        visitor.visit(function);
+        for(ValRef parameter : parameters)
+            visitor.visit(parameter);
+    }
+}