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package sun.tools.tree;

import sun.tools.java.*;
import sun.tools.asm.Assembler;
import java.io.PrintStream;
import java.util.Hashtable;

WARNING: The contents of this source file are not part of any supported API. Code that depends on them does so at its own risk: they are subject to change or removal without notice.
/** * WARNING: The contents of this source file are not part of any * supported API. Code that depends on them does so at its own risk: * they are subject to change or removal without notice. */
public abstract class AssignOpExpression extends BinaryAssignExpression { protected Type itype; // Type of intermediate result, before assigning final int NOINC = Integer.MAX_VALUE; protected FieldUpdater updater = null; // Used also in 'AssignAddExpression'.
Constructor
/** * Constructor */
public AssignOpExpression(int op, long where, Expression left, Expression right) { super(op, where, left, right); }
Select the type
/** * Select the type * */
@SuppressWarnings("fallthrough") final void selectType(Environment env, Context ctx, int tm) { Type rtype = null; // special conversion type for RHS switch(op) { case ASGADD: if (left.type == Type.tString) { if (right.type == Type.tVoid) { // The type of the right hand side can be // anything except void. Fix for 4119864. env.error(where, "incompatible.type", opNames[op], Type.tVoid, Type.tString); type = Type.tError; } else { type = itype = Type.tString; } return; } /* Fall through */ case ASGDIV: case ASGMUL: case ASGSUB: case ASGREM: if ((tm & TM_DOUBLE) != 0) { itype = Type.tDouble; } else if ((tm & TM_FLOAT) != 0) { itype = Type.tFloat; } else if ((tm & TM_LONG) != 0) { itype = Type.tLong; } else { itype = Type.tInt; } break; case ASGBITAND: case ASGBITOR: case ASGBITXOR: if ((tm & TM_BOOLEAN) != 0) { itype = Type.tBoolean; } else if ((tm & TM_LONG) != 0) { itype = Type.tLong; } else { itype = Type.tInt; } break; case ASGLSHIFT: case ASGRSHIFT: case ASGURSHIFT: rtype = Type.tInt; // Fix for bug 4134459. // We allow any integral type (even long) to // be the right hand side of a shift operation. if (right.type.inMask(TM_INTEGER)) { right = new ConvertExpression(where, Type.tInt, right); } // The intermediate type of the expression is the // type of the left hand side after undergoing // unary (not binary) type promotion. We ignore // tm -- it contains information about both left // and right hand sides -- and we compute the // type only from the type of the lhs. if (left.type == Type.tLong) { itype = Type.tLong; } else { itype = Type.tInt; } break; default: throw new CompilerError("Bad assignOp type: " + op); } if (rtype == null) { rtype = itype; } right = convert(env, ctx, rtype, right); // The result is always the type of the left operand. type = left.type; }
Get the increment, return NOINC if an increment is not possible
/** * Get the increment, return NOINC if an increment is not possible */
int getIncrement() { if ((left.op == IDENT) && type.isType(TC_INT) && (right.op == INTVAL)) if ((op == ASGADD) || (op == ASGSUB)) if (((IdentifierExpression)left).field.isLocal()) { int val = ((IntExpression)right).value; if (op == ASGSUB) val = -val; if (val == (short)val) return val; } return NOINC; }
Check an assignment expression
/** * Check an assignment expression */
public Vset checkValue(Environment env, Context ctx, Vset vset, Hashtable<Object, Object> exp) { vset = left.checkAssignOp(env, ctx, vset, exp, this); vset = right.checkValue(env, ctx, vset, exp); int tm = left.type.getTypeMask() | right.type.getTypeMask(); if ((tm & TM_ERROR) != 0) { return vset; } selectType(env, ctx, tm); if (!type.isType(TC_ERROR)) { convert(env, ctx, itype, left); } updater = left.getUpdater(env, ctx); // Must be called after 'checkAssignOp'. return vset; }
Inline
/** * Inline */
public Expression inlineValue(Environment env, Context ctx) { // Why not inlineLHS? But that does not work. left = left.inlineValue(env, ctx); right = right.inlineValue(env, ctx); if (updater != null) { updater = updater.inline(env, ctx); } return this; }
Create a copy of the expression for method inlining
/** * Create a copy of the expression for method inlining */
public Expression copyInline(Context ctx) { AssignOpExpression e = (AssignOpExpression)clone(); e.left = left.copyInline(ctx); e.right = right.copyInline(ctx); if (updater != null) { e.updater = updater.copyInline(ctx); } return e; }
The cost of inlining this statement
/** * The cost of inlining this statement */
public int costInline(int thresh, Environment env, Context ctx) { /*----------* return (getIncrement() != NOINC) ? 2 : (3 + super.costInline(thresh, env, ctx)); *----------*/ if (updater == null) { return (getIncrement() != NOINC) // Increment variable in place. Count 3 bytes for 'iinc'. ? 3 // Cost of rhs expression + cost of lhs expression + cost // of load/op/store instructions. E.g.: iload = 1 or 2, // istore = 1 or 2, iadd = 1. Cost could be higher if // getfield/putfield or conversions needed, lower if rhs is // a small constant. Costs are highly approximate. : right.costInline(thresh, env, ctx) + left.costInline(thresh, env, ctx) + 4; } else { // Cost of rhs expression + (2 * cost of access method call) + // cost of operator. Does not account for cost of conversions, // or duplications in value-needed context. return right.costInline(thresh, env, ctx) + updater.costInline(thresh, env, ctx, true) + 1; } }
Code
/** * Code */
void code(Environment env, Context ctx, Assembler asm, boolean valNeeded) { // Handle cases in which a '+=' or '-=' operator can be optimized using // the 'iinc' instruction. See also 'IncDecExpression.codeIncDec'. // The 'iinc' instruction cannot be used if an access method call is required. int val = getIncrement(); if (val != NOINC && updater == null) { int v = ((LocalMember)((IdentifierExpression)left).field).number; int[] operands = { v, val }; asm.add(where, opc_iinc, operands); if (valNeeded) { left.codeValue(env, ctx, asm); } return; } if (updater == null) { // Field is directly accessible. int depth = left.codeLValue(env, ctx, asm); codeDup(env, ctx, asm, depth, 0); left.codeLoad(env, ctx, asm); codeConversion(env, ctx, asm, left.type, itype); right.codeValue(env, ctx, asm); codeOperation(env, ctx, asm); codeConversion(env, ctx, asm, itype, type); if (valNeeded) { codeDup(env, ctx, asm, type.stackSize(), depth); } left.codeStore(env, ctx, asm); } else { // Must use access methods. updater.startUpdate(env, ctx, asm, false); codeConversion(env, ctx, asm, left.type, itype); right.codeValue(env, ctx, asm); codeOperation(env, ctx, asm); codeConversion(env, ctx, asm, itype, type); updater.finishUpdate(env, ctx, asm, valNeeded); } } public void codeValue(Environment env, Context ctx, Assembler asm) { code(env, ctx, asm, true); } public void code(Environment env, Context ctx, Assembler asm) { code(env, ctx, asm, false); }
Print
/** * Print */
public void print(PrintStream out) { out.print("(" + opNames[op] + " "); left.print(out); out.print(" "); right.print(out); out.print(")"); } }