Class IincInstruction

  extended byorg.multijava.util.classfile.AbstractInstructionAccessor
      extended byorg.multijava.util.classfile.Instruction
          extended byorg.multijava.util.classfile.IincInstruction
All Implemented Interfaces:
Constants, InstructionAccessor

public class IincInstruction
extends Instruction

Some instructions are perniticky enough that its simpler to write them separately instead of smushing them with all the rest. The iinc instruction is one of them. A wide prefix is automatically added if either the variable index exceeds 256, or the increment value lies outside the range [-128, 127] The VM spec is unclear on how the wide instruction is implemented, but the implementation makes both the constant and the variable index 16 bit values for the wide version of this instruction.

Field Summary
private  int inc
private  int var
Fields inherited from class org.multijava.util.classfile.Instruction
Fields inherited from interface org.multijava.util.classfile.Constants
ACC_ABSTRACT, ACC_FINAL, ACC_INTERFACE, ACC_NATIVE, ACC_PRIVATE, ACC_PROTECTED, ACC_PUBLIC, ACC_STATIC, ACC_STRICT, ACC_SUPER, ACC_SYNCHRONIZED, ACC_SYNTHETIC, ACC_TRANSIENT, ACC_VOLATILE, ACCESS_FLAG_ARRAY, ACCESS_FLAG_NAMES, ATT_ANCHOR, ATT_BRIDGE, ATT_CODE, ATT_CONSTANTVALUE, ATT_DEPRECATED, ATT_DISPATCHER, ATT_EXCEPTIONS, ATT_GENERIC, ATT_GENERIC_FUNCTIONS, ATT_INNERCLASSES, ATT_LINENUMBERTABLE, ATT_LOCALVARIABLETABLE, ATT_MM_BODY, ATT_REDIRECTOR, ATT_RMJ_GLUE, ATT_RMJ_SIGNATURE, ATT_RUNTIME_VISIBLE_ANNOTATIONS, ATT_RUNTIME_VISIBLE_PARAMETER_ANNOTATIONS, ATT_SIGNATURE, ATT_SOURCEFILE, ATT_SYNTHETIC, ATT_UNIVERSE_FIELD, ATT_UNIVERSE_METHOD, ATT_UNIVERSE_VERSION, CST_CLASS, CST_DOUBLE, CST_FIELD, CST_FLOAT, CST_INTEGER, CST_INTERFACEMETHOD, CST_LONG, CST_METHOD, CST_NAMEANDTYPE, CST_STRING, CST_UTF8, ENV_DEBUG_MODE, ENV_USE_CACHE, JAVA_MAGIC, JAVA_MAJOR, JAVA_MINOR, MAX_CODE_PER_METHOD, 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_athrow, opc_baload, opc_bastore, opc_bipush, 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_dup2, opc_dup2_x1, opc_dup2_x2, opc_dup_x1, opc_dup_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_ldc2_w, opc_ldc_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_putstatic, opc_ret, opc_return, opc_saload, opc_sastore, opc_sipush, opc_swap, opc_tableswitch, opc_wide, opc_xxxunusedxxx, POO_ASCII_CONSTANT, POO_CLASS_CONSTANT, POO_DOUBLE_CONSTANT, POO_FLOAT_CONSTANT, POO_INTEGER_CONSTANT, POO_LONG_CONSTANT, POO_NAT_CONSTANT, POO_REF_CONSTANT, POO_STRING_CONSTANT, TYP_ADDRESS, TYP_DOUBLE, TYP_FLOAT, TYP_INT, TYP_LONG, TYP_REFERENCE, TYP_VOID
Constructor Summary
IincInstruction(int var, int inc)
          Constructs a new iinc instruction
Method Summary
 boolean canComplete()
          Returns true iff control flow can reach the next instruction in textual order.
 int getIncrement()
          Return the value that is added to this variable
 int getPushedOnStack()
          Returns the size of data pushed on the stack by this instruction
 byte getReturnType()
          Returns the type pushed on the stack
(package private)  int getSize()
          Returns the number of bytes used by the the instruction in the code array.
 int getStack()
          Return the amount of stack (positive or negative) used by this instruction
 int getVariable()
          Return the position of this variable in the local var set
private  boolean isWide()
          Return true if this instruction is implemented with a wide increment
(package private)  void resolveConstants(ConstantPool cp)
          Insert or check location of constant value on constant pool
(package private)  void write(ConstantPool cp, DataOutput out)
          Write this instruction into a file
Methods inherited from class org.multijava.util.classfile.Instruction
check, computeEndAddress, dump, getAddress, getLocalVar, getOpcode, getPoppedFromStack, isLiteral, setAddress, setOpcode
Methods inherited from class org.multijava.util.classfile.AbstractInstructionAccessor
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail


private int var


private int inc
Constructor Detail


public IincInstruction(int var,
                       int inc)
Constructs a new iinc instruction

var - the index of the variable to be incremented.
inc - value to be added to the variable.
Method Detail


public boolean canComplete()
Returns true iff control flow can reach the next instruction in textual order.


void resolveConstants(ConstantPool cp)
Insert or check location of constant value on constant pool

cp - the constant pool for this class


int getSize()
Returns the number of bytes used by the the instruction in the code array.


public int getIncrement()
Return the value that is added to this variable


public int getVariable()
Return the position of this variable in the local var set


public byte getReturnType()
Returns the type pushed on the stack


public int getPushedOnStack()
Returns the size of data pushed on the stack by this instruction


public int getStack()
Return the amount of stack (positive or negative) used by this instruction


void write(ConstantPool cp,
           DataOutput out)
     throws IOException
Write this instruction into a file

cp - the constant pool that contain all data
out - the file where to write this object info
IOException - an io problem has occured


private boolean isWide()
Return true if this instruction is implemented with a wide increment


JML is Copyright (C) 1998-2002 by Iowa State University and is distributed under the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This release depends on code from the MultiJava project and is based in part on the Kopi project Copyright (C) 1990-99 DMS Decision Management Systems Ges.m.b.H.