Java example source code file (AssignOpExpression.java)
The AssignOpExpression.java Java example source code/*
* Copyright (c) 1994, 2003, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
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.
*/
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
*/
public AssignOpExpression(int op, long where, Expression left, Expression right) {
super(op, where, left, right);
}
/**
* Select the type
*
*/
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
*/
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
*/
public Vset checkValue(Environment env, Context ctx, Vset vset, Hashtable 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
*/
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
*/
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
*/
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
*/
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
*/
public void print(PrintStream out) {
out.print("(" + opNames[op] + " ");
left.print(out);
out.print(" ");
right.print(out);
out.print(")");
}
}
Other Java examples (source code examples)Here is a short list of links related to this Java AssignOpExpression.java source code file: |
The search page
Other Java source code examples at this package level
Click here to learn more about this project
