Class CodeGenerator

java.lang.Object

EDU.purdue.cs.bloat.tree.TreeVisitor

EDU.purdue.cs.bloat.codegen.CodeGenerator

All Implemented Interfaces:

Opcode

public class CodeGenerator
extends TreeVisitor
implements Opcode

CodeGenerator performs some final optimizations and is used (via a visitor) to generate bytecode for the contents of a control flow graph.

See Also:

• FlowGraph

Field Summary

Fields

Modifier and Type	Field	Description
static boolean	DB_OPT_STACK
static boolean	DEBUG
protected MethodEditor	method
protected Block	next
boolean	nowb
static boolean	OPT_STACK	Use information about placement of local variables to eliminate loads and stores in favor of stack manipulations
protected Map	postponedInstructions
protected int	stackHeight
static boolean	USE_PERSISTENT
protected Set	visited

Fields inherited from class TreeVisitor

FORWARD, REVERSE

Fields inherited from interface Opcode

opc_aaload, opc_aastore, opc_aconst_null, opc_aload, opc_aload_0, opc_aload_1, opc_aload_2, opc_aload_3, opc_anewarray, opc_areturn, opc_arraylength, opc_astore, opc_astore_0, opc_astore_1, opc_astore_2, opc_astore_3, opc_aswizzle, opc_aswrange, opc_athrow, opc_aupdate, opc_baload, opc_bastore, opc_bipush, opc_breakpoint, opc_caload, opc_castore, opc_checkcast, opc_d2f, opc_d2i, opc_d2l, opc_dadd, opc_daload, opc_dastore, opc_dcmpg, opc_dcmpl, opc_dconst_0, opc_dconst_1, opc_ddiv, opc_dload, opc_dload_0, opc_dload_1, opc_dload_2, opc_dload_3, opc_dmul, opc_dneg, opc_drem, opc_dreturn, opc_dstore, opc_dstore_0, opc_dstore_1, opc_dstore_2, opc_dstore_3, opc_dsub, opc_dup, opc_dup_x1, opc_dup_x2, opc_dup2, opc_dup2_x1, opc_dup2_x2, opc_f2d, opc_f2i, opc_f2l, opc_fadd, opc_faload, opc_fastore, opc_fcmpg, opc_fcmpl, opc_fconst_0, opc_fconst_1, opc_fconst_2, opc_fdiv, opc_fload, opc_fload_0, opc_fload_1, opc_fload_2, opc_fload_3, opc_fmul, opc_fneg, opc_frem, opc_freturn, opc_fstore, opc_fstore_0, opc_fstore_1, opc_fstore_2, opc_fstore_3, opc_fsub, opc_getfield, opc_getstatic, opc_goto, opc_goto_w, opc_i2b, opc_i2c, opc_i2d, opc_i2f, opc_i2l, opc_i2s, opc_iadd, opc_iaload, opc_iand, opc_iastore, opc_iconst_0, opc_iconst_1, opc_iconst_2, opc_iconst_3, opc_iconst_4, opc_iconst_5, opc_iconst_m1, opc_idiv, opc_if_acmpeq, opc_if_acmpne, opc_if_icmpeq, opc_if_icmpge, opc_if_icmpgt, opc_if_icmple, opc_if_icmplt, opc_if_icmpne, opc_ifeq, opc_ifge, opc_ifgt, opc_ifle, opc_iflt, opc_ifne, opc_ifnonnull, opc_ifnull, opc_iinc, opc_iload, opc_iload_0, opc_iload_1, opc_iload_2, opc_iload_3, opc_imul, opc_ineg, opc_instanceof, opc_invokeinterface, opc_invokespecial, opc_invokestatic, opc_invokevirtual, opc_ior, opc_irem, opc_ireturn, opc_ishl, opc_ishr, opc_istore, opc_istore_0, opc_istore_1, opc_istore_2, opc_istore_3, opc_isub, opc_iushr, opc_ixor, opc_jsr, opc_jsr_w, opc_l2d, opc_l2f, opc_l2i, opc_ladd, opc_laload, opc_land, opc_lastore, opc_lcmp, opc_lconst_0, opc_lconst_1, opc_ldc, opc_ldc_w, opc_ldc2_w, opc_ldiv, opc_lload, opc_lload_0, opc_lload_1, opc_lload_2, opc_lload_3, opc_lmul, opc_lneg, opc_lookupswitch, opc_lor, opc_lrem, opc_lreturn, opc_lshl, opc_lshr, opc_lstore, opc_lstore_0, opc_lstore_1, opc_lstore_2, opc_lstore_3, opc_lsub, opc_lushr, opc_lxor, opc_monitorenter, opc_monitorexit, opc_multianewarray, opc_new, opc_newarray, opc_nop, opc_pop, opc_pop2, opc_putfield, opc_putfield_nowb, opc_putstatic, opc_putstatic_nowb, opc_rc, opc_ret, opc_return, opc_saload, opc_sastore, opc_sipush, opc_supdate, opc_swap, opc_tableswitch, opc_wide, opc_xxxunusedxxx, opcNames, opcSize, opcx_aaload, opcx_aastore, opcx_aload, opcx_areturn, opcx_arraylength, opcx_astore, opcx_aswizzle, opcx_aswrange, opcx_athrow, opcx_aupdate, opcx_baload, opcx_bastore, opcx_caload, opcx_castore, opcx_checkcast, opcx_d2f, opcx_d2i, opcx_d2l, opcx_dadd, opcx_daload, opcx_dastore, opcx_dcmpg, opcx_dcmpl, opcx_ddiv, opcx_dload, opcx_dmul, opcx_dneg, opcx_drem, opcx_dreturn, opcx_dstore, opcx_dsub, opcx_dup, opcx_dup_x1, opcx_dup_x2, opcx_dup2, opcx_dup2_x1, opcx_dup2_x2, opcx_f2d, opcx_f2i, opcx_f2l, opcx_fadd, opcx_faload, opcx_fastore, opcx_fcmpg, opcx_fcmpl, opcx_fdiv, opcx_fload, opcx_fmul, opcx_fneg, opcx_frem, opcx_freturn, opcx_fstore, opcx_fsub, opcx_getfield, opcx_getstatic, opcx_goto, opcx_i2b, opcx_i2c, opcx_i2d, opcx_i2f, opcx_i2l, opcx_i2s, opcx_iadd, opcx_iaload, opcx_iand, opcx_iastore, opcx_idiv, opcx_if_acmpeq, opcx_if_acmpne, opcx_if_icmpeq, opcx_if_icmpge, opcx_if_icmpgt, opcx_if_icmple, opcx_if_icmplt, opcx_if_icmpne, opcx_ifeq, opcx_ifge, opcx_ifgt, opcx_ifle, opcx_iflt, opcx_ifne, opcx_ifnonnull, opcx_ifnull, opcx_iinc, opcx_iload, opcx_imul, opcx_ineg, opcx_instanceof, opcx_invokeinterface, opcx_invokespecial, opcx_invokestatic, opcx_invokevirtual, opcx_ior, opcx_irem, opcx_ireturn, opcx_ishl, opcx_ishr, opcx_istore, opcx_isub, opcx_iushr, opcx_ixor, opcx_jsr, opcx_l2d, opcx_l2f, opcx_l2i, opcx_ladd, opcx_laload, opcx_land, opcx_lastore, opcx_lcmp, opcx_ldc, opcx_ldiv, opcx_lload, opcx_lmul, opcx_lneg, opcx_lor, opcx_lrem, opcx_lreturn, opcx_lshl, opcx_lshr, opcx_lstore, opcx_lsub, opcx_lushr, opcx_lxor, opcx_monitorenter, opcx_monitorexit, opcx_multianewarray, opcx_new, opcx_newarray, opcx_nop, opcx_pop, opcx_pop2, opcx_putfield, opcx_putfield_nowb, opcx_putstatic, opcx_putstatic_nowb, opcx_rc, opcx_ret, opcx_return, opcx_saload, opcx_sastore, opcx_supdate, opcx_swap, opcx_switch, opcXMap, VARIABLE

Constructor Summary

Constructors

Constructor	Description
CodeGenerator(MethodEditor method)	Constructor.

Method Summary

Modifier and Type	Method	Description
void	allocReturnAddresses(FlowGraph cfg, RegisterAllocator alloc)	Allocate "registers" (LocalVariables) for the return addresses for each subroutine in the method.
protected Stmt	createStore(VarExpr target, Expr source)	Returns an ExprStmt that contains a store of the source into the target.
protected Stmt	createUndefinedStore(VarExpr target)	Create a ExprStmt that initializes a target variable to a default value based on the type of the target.
void	replacePhis(FlowGraph cfg)	Replace PhiStmts with copies that accomplish what the PhiStmts represent.
void	simplifyControlFlow(FlowGraph cfg)	Simplifies the control flow of a method by changing jump and return statements into gotos where appropriate.
void	visitAddressStoreStmt(AddressStoreStmt stmt)
void	visitArithExpr(ArithExpr expr)
void	visitArrayLengthExpr(ArrayLengthExpr expr)
void	visitArrayRefExpr(ArrayRefExpr expr)
void	visitCallMethodExpr(CallMethodExpr expr)
void	visitCallStaticExpr(CallStaticExpr expr)
void	visitCastExpr(CastExpr expr)
void	visitCatchExpr(CatchExpr expr)
void	visitConstantExpr(ConstantExpr expr)
void	visitDefExpr(DefExpr expr)
void	visitExpr(Expr expr)
void	visitExprStmt(ExprStmt stmt)
void	visitFieldExpr(FieldExpr expr)
void	visitFlowGraph(FlowGraph cfg)	Visits the nodes in the method's control flow graph and ensures that information about the method's basic blocks is consistent and correct.
void	visitGotoStmt(GotoStmt stmt)
void	visitIfCmpStmt(IfCmpStmt stmt)
void	visitIfZeroStmt(IfZeroStmt stmt)
void	visitInitStmt(InitStmt stmt)
void	visitInstanceOfExpr(InstanceOfExpr expr)
void	visitJsrStmt(JsrStmt stmt)
void	visitLabelStmt(LabelStmt stmt)
void	visitLocalExpr(LocalExpr expr)
void	visitMonitorStmt(MonitorStmt stmt)
void	visitNegExpr(NegExpr expr)
void	visitNewArrayExpr(NewArrayExpr expr)
void	visitNewExpr(NewExpr expr)
void	visitNewMultiArrayExpr(NewMultiArrayExpr expr)
void	visitPhiStmt(PhiStmt stmt)
void	visitRCExpr(RCExpr expr)
void	visitRetStmt(RetStmt stmt)
void	visitReturnAddressExpr(ReturnAddressExpr expr)
void	visitReturnExprStmt(ReturnExprStmt stmt)
void	visitReturnStmt(ReturnStmt stmt)
void	visitSCStmt(SCStmt stmt)
void	visitShiftExpr(ShiftExpr expr)
void	visitSRStmt(SRStmt stmt)
void	visitStackExpr(StackExpr expr)
void	visitStackManipStmt(StackManipStmt stmt)
void	visitStaticFieldExpr(StaticFieldExpr expr)
void	visitStoreExpr(StoreExpr expr)
void	visitSwitchStmt(SwitchStmt stmt)
void	visitThrowStmt(ThrowStmt stmt)
void	visitUCExpr(UCExpr expr)
void	visitZeroCheckExpr(ZeroCheckExpr expr)

Methods inherited from class TreeVisitor

direction, forward, prune, reverse, setPrune, visitBlock, visitCallExpr, visitCheckExpr, visitIfStmt, visitMemExpr, visitMemRefExpr, visitNode, visitPhiCatchStmt, visitPhiJoinStmt, visitStmt, visitTree, visitVarExpr

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

DEBUG

public static boolean DEBUG

USE_PERSISTENT

public static boolean USE_PERSISTENT

OPT_STACK

public static boolean OPT_STACK

Use information about placement of local variables to eliminate loads and stores in favor of stack manipulations

DB_OPT_STACK

public static boolean DB_OPT_STACK

method

protected MethodEditor method

visited

protected Set visited

postponedInstructions

protected Map postponedInstructions

next

protected Block next

stackHeight

protected int stackHeight

nowb

public boolean nowb

Constructor Details

CodeGenerator

public CodeGenerator(MethodEditor method)

Constructor.

Parameters:

method - The method for which bytecode is generated.

Method Details

visitFlowGraph

public void visitFlowGraph(FlowGraph cfg)

Visits the nodes in the method's control flow graph and ensures that information about the method's basic blocks is consistent and correct.

Overrides:

visitFlowGraph in class TreeVisitor

Parameters:

cfg - The control flow graph associated with this method.

simplifyControlFlow

public void simplifyControlFlow(FlowGraph cfg)

Simplifies the control flow of a method by changing jump and return statements into gotos where appropriate.

replacePhis

public void replacePhis(FlowGraph cfg)

Replace PhiStmts with copies that accomplish what the PhiStmts represent. Then remove the PhiStmts from the control flow graph.

allocReturnAddresses

public void allocReturnAddresses(FlowGraph cfg,
 RegisterAllocator alloc)

Allocate "registers" (LocalVariables) for the return addresses for each subroutine in the method.

Parameters:

cfg - Control flow graph for the method

alloc - Allocation (and information about) the local variables in the method.

See Also:

• LocalVariable
• LocalExpr

createUndefinedStore

protected Stmt createUndefinedStore(VarExpr target)

Create a ExprStmt that initializes a target variable to a default value based on the type of the target.

createStore

protected Stmt createStore(VarExpr target,
 Expr source)

Returns an ExprStmt that contains a store of the source into the target.

visitExpr

public void visitExpr(Expr expr)

Overrides:

visitExpr in class TreeVisitor

visitExprStmt

public void visitExprStmt(ExprStmt stmt)

Overrides:

visitExprStmt in class TreeVisitor

visitInitStmt

public void visitInitStmt(InitStmt stmt)

Overrides:

visitInitStmt in class TreeVisitor

visitGotoStmt

public void visitGotoStmt(GotoStmt stmt)

Overrides:

visitGotoStmt in class TreeVisitor

visitIfCmpStmt

public void visitIfCmpStmt(IfCmpStmt stmt)

Overrides:

visitIfCmpStmt in class TreeVisitor

visitIfZeroStmt

public void visitIfZeroStmt(IfZeroStmt stmt)

Overrides:

visitIfZeroStmt in class TreeVisitor

visitLabelStmt

public void visitLabelStmt(LabelStmt stmt)

Overrides:

visitLabelStmt in class TreeVisitor

visitMonitorStmt

public void visitMonitorStmt(MonitorStmt stmt)

Overrides:

visitMonitorStmt in class TreeVisitor

visitPhiStmt

public void visitPhiStmt(PhiStmt stmt)

Overrides:

visitPhiStmt in class TreeVisitor

visitRCExpr

public void visitRCExpr(RCExpr expr)

Overrides:

visitRCExpr in class TreeVisitor

visitUCExpr

public void visitUCExpr(UCExpr expr)

Overrides:

visitUCExpr in class TreeVisitor

visitRetStmt

public void visitRetStmt(RetStmt stmt)

Overrides:

visitRetStmt in class TreeVisitor

visitReturnExprStmt

public void visitReturnExprStmt(ReturnExprStmt stmt)

Overrides:

visitReturnExprStmt in class TreeVisitor

visitReturnStmt

public void visitReturnStmt(ReturnStmt stmt)

Overrides:

visitReturnStmt in class TreeVisitor

visitStoreExpr

public void visitStoreExpr(StoreExpr expr)

Overrides:

visitStoreExpr in class TreeVisitor

visitAddressStoreStmt

public void visitAddressStoreStmt(AddressStoreStmt stmt)

Overrides:

visitAddressStoreStmt in class TreeVisitor

visitJsrStmt

public void visitJsrStmt(JsrStmt stmt)

Overrides:

visitJsrStmt in class TreeVisitor

visitSwitchStmt

public void visitSwitchStmt(SwitchStmt stmt)

Overrides:

visitSwitchStmt in class TreeVisitor

visitStackManipStmt

public void visitStackManipStmt(StackManipStmt stmt)

Overrides:

visitStackManipStmt in class TreeVisitor

visitThrowStmt

public void visitThrowStmt(ThrowStmt stmt)

Overrides:

visitThrowStmt in class TreeVisitor

visitSCStmt

public void visitSCStmt(SCStmt stmt)

Overrides:

visitSCStmt in class TreeVisitor

visitSRStmt

public void visitSRStmt(SRStmt stmt)

Overrides:

visitSRStmt in class TreeVisitor

visitArithExpr

public void visitArithExpr(ArithExpr expr)

Overrides:

visitArithExpr in class TreeVisitor

visitArrayLengthExpr

public void visitArrayLengthExpr(ArrayLengthExpr expr)

Overrides:

visitArrayLengthExpr in class TreeVisitor

visitArrayRefExpr

public void visitArrayRefExpr(ArrayRefExpr expr)

Overrides:

visitArrayRefExpr in class TreeVisitor

visitCallMethodExpr

public void visitCallMethodExpr(CallMethodExpr expr)

Overrides:

visitCallMethodExpr in class TreeVisitor

visitCallStaticExpr

public void visitCallStaticExpr(CallStaticExpr expr)

Overrides:

visitCallStaticExpr in class TreeVisitor

visitCastExpr

public void visitCastExpr(CastExpr expr)

Overrides:

visitCastExpr in class TreeVisitor

visitConstantExpr

public void visitConstantExpr(ConstantExpr expr)

Overrides:

visitConstantExpr in class TreeVisitor

visitFieldExpr

public void visitFieldExpr(FieldExpr expr)

Overrides:

visitFieldExpr in class TreeVisitor

visitInstanceOfExpr

public void visitInstanceOfExpr(InstanceOfExpr expr)

Overrides:

visitInstanceOfExpr in class TreeVisitor

visitLocalExpr

public void visitLocalExpr(LocalExpr expr)

Overrides:

visitLocalExpr in class TreeVisitor

visitNegExpr

public void visitNegExpr(NegExpr expr)

Overrides:

visitNegExpr in class TreeVisitor

visitNewArrayExpr

public void visitNewArrayExpr(NewArrayExpr expr)

Overrides:

visitNewArrayExpr in class TreeVisitor

visitNewExpr

public void visitNewExpr(NewExpr expr)

Overrides:

visitNewExpr in class TreeVisitor

visitNewMultiArrayExpr

public void visitNewMultiArrayExpr(NewMultiArrayExpr expr)

Overrides:

visitNewMultiArrayExpr in class TreeVisitor

visitReturnAddressExpr

public void visitReturnAddressExpr(ReturnAddressExpr expr)

Overrides:

visitReturnAddressExpr in class TreeVisitor

visitShiftExpr

public void visitShiftExpr(ShiftExpr expr)

Overrides:

visitShiftExpr in class TreeVisitor

visitDefExpr

public void visitDefExpr(DefExpr expr)

Overrides:

visitDefExpr in class TreeVisitor

visitCatchExpr

public void visitCatchExpr(CatchExpr expr)

Overrides:

visitCatchExpr in class TreeVisitor

visitStackExpr

public void visitStackExpr(StackExpr expr)

Overrides:

visitStackExpr in class TreeVisitor

visitStaticFieldExpr

public void visitStaticFieldExpr(StaticFieldExpr expr)

Overrides:

visitStaticFieldExpr in class TreeVisitor

visitZeroCheckExpr

public void visitZeroCheckExpr(ZeroCheckExpr expr)

Overrides:

visitZeroCheckExpr in class TreeVisitor