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Week 11 Solutions Week 13 Solutions Code Generation 1 Write Jasmin code for the following MC program int a,b[3]; float c[4],d; int foo(boolean e,int f[]) { if (e && (f[1]==0)) a = 1; else b[1] = a = 2[.]
Week 13 Solutions Code Generation Write Jasmin code for the following MC program: int main() { int a,b[3]; int e[3],f; float c[4],d; for (f = 1; f < 3; f = f +1) int foo(boolean e,int f[]) { e[f] = 0; if (e && (f[1]==0)) foo(true,e); a = 1; repeat else b[0] = a + b[0]; b[1] = a = 2; until (b[0] > 10); return a; return 0; } } Change the above MC program to Java program: public class Cout { static int a; static int b[] = new int[3]; static float c[] = new float[4]; static float d; static int foo(boolean e,int f[]) { if (e && (f[1] == 0)) a = 1; else b[1] = a = 2; return a; } void main(String[] args) { int e[] = new int[3]; int f; for (f = 1; f < 3; f = f +1) e[f] = 0; foo(true,e); b[0] = a + b[0]; while (!(b[0] > 10)); return ; } } Compile the above Java program: javac –g Cout.java Translate to jasmin code by running JavaToJasmin.bat source Cout.java class public Cout super java/lang/Object field static a I field static b [I field static c [F field static d F method public ()V limit stack limit locals var is this LCout; from Label0 to Label1 Label0: line aload_0 invokespecial java/lang/Object/()V Label1: return end method method static foo(Z[I)I limit stack limit locals var is e Z from Label3 to Label4 var is f [I from Label3 to Label4 Label3: line iload_0 ifeq Label0 aload_1 iconst_1 iaload ifne Label0 line iconst_1 putstatic Cout.a I goto Label2 Label0: line 10 getstatic Cout.b [I iconst_1 iconst_2 dup putstatic Cout.a I iastore Label2: line 11 getstatic Cout.a I Label4: ireturn end method method main([Ljava/lang/String;)V limit stack limit locals var is this LCout; from Label3 to Label4 var is args [Ljava/lang/String; from Label3 to Label4 var is e [I from Label7 to Label4 var is f I from Label1 to Label4 Label3: line 15 iconst_3 newarray int astore_2 Label7: line 17 iconst_1 istore_3 Label1: iload_3 iconst_3 if_icmpge Label0 line 18 aload_2 iload_3 iconst_0 iastore line 17 iload_3 iconst_1 iadd istore_3 goto Label1 Label0: line 19 iconst_1 aload_2 invokestatic Cout/foo(Z[I)I pop Label2: line 21 getstatic Cout.b [I iconst_0 getstatic Cout.a I getstatic Cout.b [I iconst_0 iaload iadd iastore line 22 getstatic Cout.b [I iconst_0 iaload bipush 10 if_icmple Label2 Label4: line 23 return end method method static ()V limit stack limit locals line iconst_3 newarray int putstatic Cout.b [I line iconst_4 newarray float putstatic Cout.c [F return end method Given the following grammar: S’ → P P → T id ; P | F F → T id (T id) { D L } F | ∈ D → T id ; D | ∈ L→SL|∈ S→E;|{DL} T → int | float E→T=E|T T→T+U|U U → INTLIT | FLOATLIT| id | id ( E ) | ( E ) Based on the interfaces of SymTable.java, SymEntry.java, Frame.java and Emitter.java, write translation schemes to generate code for: a Jasmin directives: source, class, super Let e keep an instance of Emitter, symtable an instance of SymTable S’ → {e.printout(e.emitPROLOG()); symtable.enterScope();} P {symtable.exitScope();} b global variable declarations P → T id ; {sym = new SymEntry(id,T.type); sym.setScope(symtable.getCurrentScope()); symtable.insert(sym); e.printout(e.emitSTATICFIELD(id.Lexeme,T.type));} P T → int {T.type = Type.INT} | float {T.type = Type.FLOAT} c local variable declarations F → T id ( {if (id.Lexeme.equals(“main”)) isMain = true; else isMain = false; Frame o = new Frame(isMain); L.frame = D.frame = o; e.setFrame(o); symtable.enterScope(); o.enterScope(); } T1 id1 {index = o.getNewIndex(); sym = new SymEntry(id1,T.type); sym.setScope(symtable.getCurrentScope()); sym.setObject(new Integer(index)); symtable.insert(sym); e.printout( e.emitVAR(index,id1.Lexeme,T.type,o.getStartLabel(),o.getEndLabel()));} ){D {e.printout(e.emitLABEL(o.getStartLabel()));} L {e.printout(e.emitLABEL(o.getEndLabel()); symtable.exitScope(); o.exitScope();} }F D → T id ; { Frame o = D1.frame = D.frame; index = o.getNewIndex(); sym = new SymEntry(id,T.type); sym.setScope(symtable.getCurrentScope()); sym.setObject(new Integer(index)); symtable.insert(sym);e.printout( e.emitVAR(index,id.Lexeme,T.type,o.getStartLabel(),o.getEndLabel())); } S→ { D1 {Frame o = D.frame = L.frame = S.frame; o.enterScope();} D {e.printout(e.emitLabel(o.getStartLabel());} L L→ {e.printout(e.emitLabel(o.getEndLabel())); o.exitScope();} } {S.frame = L1.frame = L.frame} S L1 d method declarations: F → T id {sym = new SymEntry(id,null); symtable.insert(sym);} (T1 id1) {ft = new FunctionType(T1.type,T.type); sym.setType(ft); sym.setObject(MCC.CLASSNAME); e.printout(e.emitMETHOD(id.Lexeme,ft,true));} {DL {e.printout(e.emitENDMETHOD()));} }F e U U → INTLIT {U.waitCode = null; U.code = e.emitPUSHCONST(INTLIT.lexeme,Type.INT); U.type = Type.INT;} | FLOATLIT {U.waitCode = null; U.code = e.emitPUSHCONST(FLOATLIT.lexeme,Type.FLOAT); U.type = Type.FLOAT;} | id {U.waitCode = symtable.lookup(id); U.code = null; U.type = U.waitCode.getType();} | id ( E ) {U.waitCode = null; sym = symtable.lookup(id); Type pt = ((FunctionType)sym.getType()).getParameterType(); if (pt == Type.FLOAT && E.type == Type.INT) E.code += e.emitI2F(); U.code = E.code + e.emitINVOKESTATIC(((String)sym.getObject()+’/’+id.Lexeme,sym.getType()); U.type = ((FunctionType)sym.getType()).getReturnType();} | ( E ) { if (E.waitCode != null) U.code = e.emitREADVAR(E.waitCode); else U.code = E.code; U.waitCode = null; U.type = E.type;} f T T → T1 + U {if (T1.waitCode != null) T1.code = e.emitREADVAR(T1.waitCode); if (U.waitCode != null) U.code = e.emitREADVAR(U.waitCode); if (T1.type != U.type) { T.type = Type.FLOAT; if (T1.type = Type.INT) T1.code += e.emitI2F(); else U.code += e.emitI2F(); } else T.type = T1.type; T.code = T1.code + U.code + e.emitADDOP(“+”,T.type); T.waitCode = null; } | U {T.waitCode = U.waitCode; T.code = U.code;T.type = U.type;} g E E → T = E1 {if (E1.waitCode != null) E1.code = e.emitREADVAR(E1.waitCode); if (E1.type != T.type) { E.type = Type.FLOAT; E1.code += e.emitI2F(); } else E.type = T.type; E.code = E1.code + e.emitDUP() + e.emitWRITEVAR(T.waitCode); E.waitCode = null; } | T {E.waitCode = T.waitCode; E.code = T.code;E.type = T.type} Eliminating left recursion from T-productions and left factoring E-productions of the above grammar, rewrite translation schemes of 2.f and 2.g f T T→U {T’.iwaitCode = U.waitCode; T’.iCode = U.code; T’.iType = U.type;} T’ {T.waitCode = T’.owaitCode;T.code = T’.ocode; T.type = T’.otype;} T’ → + U {if (T’.iwaitCode != null) T’.icode = e.emitREADVAR(T’.iwaitCode); if (U.waitCode != null) U.code = e.emitREADVAR(U.waitCode); if (T’.itype != U.type) { T1’.itype = Type.FLOAT; if (T’.itype = Type.INT) T’.icode += e.emitI2F(); else U.code += e.emitI2F(); } else T1’.itype = T’.itype; T1’.icode = T’.icode + U.code + e.emitADDOP(“+”,T1’.itype); T1’.iwaitCode = null; } T1’ {T’.ocode = T1’.ocode; T’.otype = T1’.otype; T’.owaitCode = T1’.owaitCode;} | ∈ {T’.ocode = T’.icode; T’.otype = T’.itype; T’.owaitCode = T’.iwaitCode;} g E E→T {E’.icode = T.code; E’.iwaitCode = T.waitCode; E’.itype = T.type;} E’ {E.code = E’.ocode; E.waitCode = E’.owaitCode; E.type = E’.otype;} E’ → = E {if (E.waitCode != null) E.code = e.emitREADVAR(E.waitCode); if (E.type != E’.type) { E’.otype = Type.FLOAT; E.code += e.emitI2F(); } else E’.otype = E’.itype; E’.ocode = E.code + e.emitDUP() + e.emitWRITEVAR(E’.iwaitCode); E’.owaitCode = null; } | ∈ {E’.otype = E’.itype; E’.ocode = E’.icode; E’.owaitCode = E’.iwaitCode;}