1 /* 2 * Copyright (c) 2013, 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. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "memory/allocation.inline.hpp" 27 #include "opto/addnode.hpp" 28 #include "opto/cfgnode.hpp" 29 #include "opto/machnode.hpp" 30 #include "opto/matcher.hpp" 31 #include "opto/mathexactnode.hpp" 32 #include "opto/subnode.hpp" 33 34 template <typename OverflowOp> 35 class AddHelper { 36 public: 37 typedef typename OverflowOp::TypeClass TypeClass; 38 typedef typename TypeClass::NativeType NativeType; 39 40 static bool will_overflow(NativeType value1, NativeType value2) { 41 NativeType result = value1 + value2; 42 // Hacker's Delight 2-12 Overflow if both arguments have the opposite sign of the result 43 if (((value1 ^ result) & (value2 ^ result)) >= 0) { 44 return false; 45 } 46 return true; 47 } 48 49 static bool can_overflow(const Type* type1, const Type* type2) { 50 if (type1 == TypeClass::ZERO || type2 == TypeClass::ZERO) { 51 return false; 52 } 53 return true; 54 } 55 }; 56 57 template <typename OverflowOp> 58 class SubHelper { 59 public: 60 typedef typename OverflowOp::TypeClass TypeClass; 61 typedef typename TypeClass::NativeType NativeType; 62 63 static bool will_overflow(NativeType value1, NativeType value2) { 64 NativeType result = value1 - value2; 65 // hacker's delight 2-12 overflow iff the arguments have different signs and 66 // the sign of the result is different than the sign of arg1 67 if (((value1 ^ value2) & (value1 ^ result)) >= 0) { 68 return false; 69 } 70 return true; 71 } 72 73 static bool can_overflow(const Type* type1, const Type* type2) { 74 if (type2 == TypeClass::ZERO) { 75 return false; 76 } 77 return true; 78 } 79 }; 80 81 template <typename OverflowOp> 82 class MulHelper { 83 public: 84 typedef typename OverflowOp::TypeClass TypeClass; 85 86 static bool can_overflow(const Type* type1, const Type* type2) { 87 if (type1 == TypeClass::ZERO || type2 == TypeClass::ZERO) { 88 return false; 89 } else if (type1 == TypeClass::ONE || type2 == TypeClass::ONE) { 90 return false; 91 } 92 return true; 93 } 94 }; 95 96 bool OverflowAddINode::will_overflow(jint v1, jint v2) const { 97 return AddHelper<OverflowAddINode>::will_overflow(v1, v2); 98 } 99 100 bool OverflowSubINode::will_overflow(jint v1, jint v2) const { 101 return SubHelper<OverflowSubINode>::will_overflow(v1, v2); 102 } 103 104 bool OverflowMulINode::will_overflow(jint v1, jint v2) const { 105 jlong result = (jlong) v1 * (jlong) v2; 106 if ((jint) result == result) { 107 return false; 108 } 109 return true; 110 } 111 112 bool OverflowAddLNode::will_overflow(jlong v1, jlong v2) const { 113 return AddHelper<OverflowAddLNode>::will_overflow(v1, v2); 114 } 115 116 bool OverflowSubLNode::will_overflow(jlong v1, jlong v2) const { 117 return SubHelper<OverflowSubLNode>::will_overflow(v1, v2); 118 } 119 120 bool OverflowMulLNode::will_overflow(jlong val1, jlong val2) const { 121 jlong result = val1 * val2; 122 jlong ax = (val1 < 0 ? -val1 : val1); 123 jlong ay = (val2 < 0 ? -val2 : val2); 124 125 bool overflow = false; 126 if ((ax | ay) & CONST64(0xFFFFFFFF00000000)) { 127 // potential overflow if any bit in upper 32 bits are set 128 if ((val1 == min_jlong && val2 == -1) || (val2 == min_jlong && val1 == -1)) { 129 // -1 * Long.MIN_VALUE will overflow 130 overflow = true; 131 } else if (val2 != 0 && (result / val2 != val1)) { 132 overflow = true; 133 } 134 } 135 136 return overflow; 137 } 138 139 template <typename OverflowOp> 140 struct IdealHelper { 141 typedef typename OverflowOp::TypeClass TypeClass; // TypeInt, TypeLong 142 typedef typename TypeClass::NativeType NativeType; 143 144 static Node* Ideal(const OverflowOp* node, PhaseGVN* phase, bool can_reshape) { 145 Node* arg1 = node->in(1); 146 Node* arg2 = node->in(2); 147 const Type* type1 = phase->type(arg1); 148 const Type* type2 = phase->type(arg2); 149 150 if (type1 != Type::TOP && type1->singleton() && 151 type2 != Type::TOP && type2->singleton()) { 152 NativeType val1 = TypeClass::as_self(type1)->get_con(); 153 NativeType val2 = TypeClass::as_self(type2)->get_con(); 154 if (node->will_overflow(val1, val2) == false) { 155 Node* con_result = ConINode::make(phase->C, 0); 156 return con_result; 157 } 158 return NULL; 159 } 160 return NULL; 161 } 162 163 static const Type* Value(const OverflowOp* node, PhaseTransform* phase) { 164 const Type *t1 = phase->type( node->in(1) ); 165 const Type *t2 = phase->type( node->in(2) ); 166 if( t1 == Type::TOP ) return Type::TOP; 167 if( t2 == Type::TOP ) return Type::TOP; 168 169 const TypeClass* i1 = TypeClass::as_self(t1); 170 const TypeClass* i2 = TypeClass::as_self(t2); 171 172 if (t1->singleton() && t2->singleton()) { 173 if (i1 == NULL || i2 == NULL) { 174 return TypeInt::CC; 175 } 176 177 NativeType val1 = i1->get_con(); 178 NativeType val2 = i2->get_con(); 179 if (node->will_overflow(val1, val2)) { 180 return TypeInt::CC; 181 } 182 return TypeInt::ZERO; 183 } else if (i1 != TypeClass::TYPE_DOMAIN && i2 != TypeClass::TYPE_DOMAIN) { 184 if (node->will_overflow(i1->_lo, i2->_lo)) { 185 return TypeInt::CC; 186 } else if (node->will_overflow(i1->_lo, i2->_hi)) { 187 return TypeInt::CC; 188 } else if (node->will_overflow(i1->_hi, i2->_lo)) { 189 return TypeInt::CC; 190 } else if (node->will_overflow(i1->_hi, i2->_hi)) { 191 return TypeInt::CC; 192 } 193 return TypeInt::ZERO; 194 } 195 196 if (!node->can_overflow(t1, t2)) { 197 return TypeInt::ZERO; 198 } 199 return TypeInt::CC; 200 } 201 }; 202 203 Node* OverflowINode::Ideal(PhaseGVN* phase, bool can_reshape) { 204 return IdealHelper<OverflowINode>::Ideal(this, phase, can_reshape); 205 } 206 207 Node* OverflowLNode::Ideal(PhaseGVN* phase, bool can_reshape) { 208 return IdealHelper<OverflowLNode>::Ideal(this, phase, can_reshape); 209 } 210 211 const Type* OverflowINode::Value(PhaseTransform* phase) const { 212 return IdealHelper<OverflowINode>::Value(this, phase); 213 } 214 215 const Type* OverflowLNode::Value(PhaseTransform* phase) const { 216 return IdealHelper<OverflowLNode>::Value(this, phase); 217 } 218 219 bool OverflowAddINode::can_overflow(const Type* t1, const Type* t2) const { 220 return AddHelper<OverflowAddINode>::can_overflow(t1, t2); 221 } 222 223 bool OverflowSubINode::can_overflow(const Type* t1, const Type* t2) const { 224 if (in(1) == in(2)) { 225 return false; 226 } 227 return SubHelper<OverflowSubINode>::can_overflow(t1, t2); 228 } 229 230 bool OverflowMulINode::can_overflow(const Type* t1, const Type* t2) const { 231 return MulHelper<OverflowMulINode>::can_overflow(t1, t2); 232 } 233 234 bool OverflowAddLNode::can_overflow(const Type* t1, const Type* t2) const { 235 return AddHelper<OverflowAddLNode>::can_overflow(t1, t2); 236 } 237 238 bool OverflowSubLNode::can_overflow(const Type* t1, const Type* t2) const { 239 if (in(1) == in(2)) { 240 return false; 241 } 242 return SubHelper<OverflowSubLNode>::can_overflow(t1, t2); 243 } 244 245 bool OverflowMulLNode::can_overflow(const Type* t1, const Type* t2) const { 246 return MulHelper<OverflowMulLNode>::can_overflow(t1, t2); 247 } 248 249 const Type* OverflowNode::sub(const Type* t1, const Type* t2) const { 250 fatal(err_msg_res("sub() should not be called for '%s'", NodeClassNames[this->Opcode()])); 251 return TypeInt::CC; 252 }