| /* |
| * 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 sun.tools.asm.Label; |
| 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 |
| class NotExpression extends UnaryExpression { |
| /** |
| * Constructor |
| */ |
| public NotExpression(long where, Expression right) { |
| super(NOT, where, Type.tBoolean, right); |
| } |
| |
| /** |
| * Select the type of the expression |
| */ |
| void selectType(Environment env, Context ctx, int tm) { |
| right = convert(env, ctx, Type.tBoolean, right); |
| } |
| |
| /* |
| * Check a "not" expression. |
| * |
| * cvars is modified so that |
| * cvar.vsTrue indicates variables with a known value if |
| * the expression is true. |
| * cvars.vsFalse indicates variables with a known value if |
| * the expression is false |
| * |
| * For "not" expressions, we look at the inside expression, and then |
| * swap true and false. |
| */ |
| |
| public void checkCondition(Environment env, Context ctx, Vset vset, |
| Hashtable exp, ConditionVars cvars) { |
| right.checkCondition(env, ctx, vset, exp, cvars); |
| right = convert(env, ctx, Type.tBoolean, right); |
| // swap true and false |
| Vset temp = cvars.vsFalse; |
| cvars.vsFalse = cvars.vsTrue; |
| cvars.vsTrue = temp; |
| } |
| |
| /** |
| * Evaluate |
| */ |
| Expression eval(boolean a) { |
| return new BooleanExpression(where, !a); |
| } |
| |
| /** |
| * Simplify |
| */ |
| Expression simplify() { |
| // Check if the expression can be optimized |
| switch (right.op) { |
| case NOT: |
| return ((NotExpression)right).right; |
| |
| case EQ: |
| case NE: |
| case LT: |
| case LE: |
| case GT: |
| case GE: |
| break; |
| |
| default: |
| return this; |
| } |
| |
| // Can't negate real comparisons |
| BinaryExpression bin = (BinaryExpression)right; |
| if (bin.left.type.inMask(TM_REAL)) { |
| return this; |
| } |
| |
| // Negate comparison |
| switch (right.op) { |
| case EQ: |
| return new NotEqualExpression(where, bin.left, bin.right); |
| case NE: |
| return new EqualExpression(where, bin.left, bin.right); |
| case LT: |
| return new GreaterOrEqualExpression(where, bin.left, bin.right); |
| case LE: |
| return new GreaterExpression(where, bin.left, bin.right); |
| case GT: |
| return new LessOrEqualExpression(where, bin.left, bin.right); |
| case GE: |
| return new LessExpression(where, bin.left, bin.right); |
| } |
| return this; |
| } |
| |
| /** |
| * Code |
| */ |
| void codeBranch(Environment env, Context ctx, Assembler asm, Label lbl, boolean whenTrue) { |
| right.codeBranch(env, ctx, asm, lbl, !whenTrue); |
| } |
| |
| /** |
| * Instead of relying on the default code generation which uses |
| * conditional branching, generate a simpler stream using XOR. |
| */ |
| public void codeValue(Environment env, Context ctx, Assembler asm) { |
| right.codeValue(env, ctx, asm); |
| asm.add(where, opc_ldc, new Integer(1)); |
| asm.add(where, opc_ixor); |
| } |
| |
| } |