Showing the changes to java/pkg/sun/tools/tree/NotExpression.java (1 of 18352 files). Show all
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| 1 | +/* | |
| 2 | + * Copyright (c) 1994, 2003, Oracle and/or its affiliates. All rights reserved. | |
| 3 | + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
| 4 | + * | |
| 5 | + * This code is free software; you can redistribute it and/or modify it | |
| 6 | + * under the terms of the GNU General Public License version 2 only, as | |
| 7 | + * published by the Free Software Foundation. Oracle designates this | |
| 8 | + * particular file as subject to the "Classpath" exception as provided | |
| 9 | + * by Oracle in the LICENSE file that accompanied this code. | |
| 10 | + * | |
| 11 | + * This code is distributed in the hope that it will be useful, but WITHOUT | |
| 12 | + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 13 | + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 14 | + * version 2 for more details (a copy is included in the LICENSE file that | |
| 15 | + * accompanied this code). | |
| 16 | + * | |
| 17 | + * You should have received a copy of the GNU General Public License version | |
| 18 | + * 2 along with this work; if not, write to the Free Software Foundation, | |
| 19 | + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
| 20 | + * | |
| 21 | + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |
| 22 | + * or visit www.oracle.com if you need additional information or have any | |
| 23 | + * questions. | |
| 24 | + */ | |
| 25 | + | |
| 26 | +package sun.tools.tree; | |
| 27 | + | |
| 28 | +import sun.tools.java.*; | |
| 29 | +import sun.tools.asm.Assembler; | |
| 30 | +import sun.tools.asm.Label; | |
| 31 | +import java.util.Hashtable; | |
| 32 | + | |
| 33 | +/** | |
| 34 | + * WARNING: The contents of this source file are not part of any | |
| 35 | + * supported API. Code that depends on them does so at its own risk: | |
| 36 | + * they are subject to change or removal without notice. | |
| 37 | + */ | |
| 38 | +public | |
| 39 | +class NotExpression extends UnaryExpression { | |
| 40 | + /** | |
| 41 | + * Constructor | |
| 42 | + */ | |
| 43 | + public NotExpression(long where, Expression right) { | |
| 44 | + super(NOT, where, Type.tBoolean, right); | |
| 45 | + } | |
| 46 | + | |
| 47 | + /** | |
| 48 | + * Select the type of the expression | |
| 49 | + */ | |
| 50 | + void selectType(Environment env, Context ctx, int tm) { | |
| 51 | + right = convert(env, ctx, Type.tBoolean, right); | |
| 52 | + } | |
| 53 | + | |
| 54 | + /* | |
| 55 | + * Check a "not" expression. | |
| 56 | + * | |
| 57 | + * cvars is modified so that | |
| 58 | + * cvar.vsTrue indicates variables with a known value if | |
| 59 | + * the expression is true. | |
| 60 | + * cvars.vsFalse indicates variables with a known value if | |
| 61 | + * the expression is false | |
| 62 | + * | |
| 63 | + * For "not" expressions, we look at the inside expression, and then | |
| 64 | + * swap true and false. | |
| 65 | + */ | |
| 66 | + | |
| 67 | + public void checkCondition(Environment env, Context ctx, Vset vset, | |
| 68 | + Hashtable exp, ConditionVars cvars) { | |
| 69 | + right.checkCondition(env, ctx, vset, exp, cvars); | |
| 70 | + right = convert(env, ctx, Type.tBoolean, right); | |
| 71 | + // swap true and false | |
| 72 | + Vset temp = cvars.vsFalse; | |
| 73 | + cvars.vsFalse = cvars.vsTrue; | |
| 74 | + cvars.vsTrue = temp; | |
| 75 | + } | |
| 76 | + | |
| 77 | + /** | |
| 78 | + * Evaluate | |
| 79 | + */ | |
| 80 | + Expression eval(boolean a) { | |
| 81 | + return new BooleanExpression(where, !a); | |
| 82 | + } | |
| 83 | + | |
| 84 | + /** | |
| 85 | + * Simplify | |
| 86 | + */ | |
| 87 | + Expression simplify() { | |
| 88 | + // Check if the expression can be optimized | |
| 89 | + switch (right.op) { | |
| 90 | + case NOT: | |
| 91 | + return ((NotExpression)right).right; | |
| 92 | + | |
| 93 | + case EQ: | |
| 94 | + case NE: | |
| 95 | + case LT: | |
| 96 | + case LE: | |
| 97 | + case GT: | |
| 98 | + case GE: | |
| 99 | + break; | |
| 100 | + | |
| 101 | + default: | |
| 102 | + return this; | |
| 103 | + } | |
| 104 | + | |
| 105 | + // Can't negate real comparisons | |
| 106 | + BinaryExpression bin = (BinaryExpression)right; | |
| 107 | + if (bin.left.type.inMask(TM_REAL)) { | |
| 108 | + return this; | |
| 109 | + } | |
| 110 | + | |
| 111 | + // Negate comparison | |
| 112 | + switch (right.op) { | |
| 113 | + case EQ: | |
| 114 | + return new NotEqualExpression(where, bin.left, bin.right); | |
| 115 | + case NE: | |
| 116 | + return new EqualExpression(where, bin.left, bin.right); | |
| 117 | + case LT: | |
| 118 | + return new GreaterOrEqualExpression(where, bin.left, bin.right); | |
| 119 | + case LE: | |
| 120 | + return new GreaterExpression(where, bin.left, bin.right); | |
| 121 | + case GT: | |
| 122 | + return new LessOrEqualExpression(where, bin.left, bin.right); | |
| 123 | + case GE: | |
| 124 | + return new LessExpression(where, bin.left, bin.right); | |
| 125 | + } | |
| 126 | + return this; | |
| 127 | + } | |
| 128 | + | |
| 129 | + /** | |
| 130 | + * Code | |
| 131 | + */ | |
| 132 | + void codeBranch(Environment env, Context ctx, Assembler asm, Label lbl, boolean whenTrue) { | |
| 133 | + right.codeBranch(env, ctx, asm, lbl, !whenTrue); | |
| 134 | + } | |
| 135 | + | |
| 136 | + /** | |
| 137 | + * Instead of relying on the default code generation which uses | |
| 138 | + * conditional branching, generate a simpler stream using XOR. | |
| 139 | + */ | |
| 140 | + public void codeValue(Environment env, Context ctx, Assembler asm) { | |
| 141 | + right.codeValue(env, ctx, asm); | |
| 142 | + asm.add(where, opc_ldc, new Integer(1)); | |
| 143 | + asm.add(where, opc_ixor); | |
| 144 | + } | |
| 145 | + | |
| 146 | +} | |