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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 | } | ||