1 /* 2 * Copyright (c) 2013, 2014, 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 bool OverflowAddINode::can_overflow(const Type* t1, const Type* t2) const { 140 return AddHelper<OverflowAddINode>::can_overflow(t1, t2); 141 } 142 143 bool OverflowSubINode::can_overflow(const Type* t1, const Type* t2) const { 144 if (in(1) == in(2)) { 145 return false; 146 } 147 return SubHelper<OverflowSubINode>::can_overflow(t1, t2); 148 } 149 150 bool OverflowMulINode::can_overflow(const Type* t1, const Type* t2) const { 151 return MulHelper<OverflowMulINode>::can_overflow(t1, t2); 152 } 153 154 bool OverflowAddLNode::can_overflow(const Type* t1, const Type* t2) const { 155 return AddHelper<OverflowAddLNode>::can_overflow(t1, t2); 156 } 157 158 bool OverflowSubLNode::can_overflow(const Type* t1, const Type* t2) const { 159 if (in(1) == in(2)) { 160 return false; 161 } 162 return SubHelper<OverflowSubLNode>::can_overflow(t1, t2); 163 } 164 165 bool OverflowMulLNode::can_overflow(const Type* t1, const Type* t2) const { 166 return MulHelper<OverflowMulLNode>::can_overflow(t1, t2); 167 } 168 169 const Type* OverflowNode::sub(const Type* t1, const Type* t2) const { 170 fatal(err_msg_res("sub() should not be called for '%s'", NodeClassNames[this->Opcode()])); 171 return TypeInt::CC; 172 } 173 174 template <typename OverflowOp> 175 struct IdealHelper { 176 typedef typename OverflowOp::TypeClass TypeClass; // TypeInt, TypeLong 177 typedef typename TypeClass::NativeType NativeType; 178 179 static Node* Ideal(const OverflowOp* node, PhaseGVN* phase, bool can_reshape) { 180 Node* arg1 = node->in(1); 181 Node* arg2 = node->in(2); 182 const Type* type1 = phase->type(arg1); 183 const Type* type2 = phase->type(arg2); 184 185 if (type1 == NULL || type2 == NULL) { 186 return NULL; 187 } 188 189 if (type1 != Type::TOP && type1->singleton() && 190 type2 != Type::TOP && type2->singleton()) { 191 NativeType val1 = TypeClass::as_self(type1)->get_con(); 192 NativeType val2 = TypeClass::as_self(type2)->get_con(); 193 if (node->will_overflow(val1, val2) == false) { 194 Node* con_result = ConINode::make(0); 195 return con_result; 196 } 197 return NULL; 198 } 199 return NULL; 200 } 201 202 static const Type* Value(const OverflowOp* node, PhaseTransform* phase) { 203 const Type *t1 = phase->type( node->in(1) ); 204 const Type *t2 = phase->type( node->in(2) ); 205 if( t1 == Type::TOP ) return Type::TOP; 206 if( t2 == Type::TOP ) return Type::TOP; 207 208 const TypeClass* i1 = TypeClass::as_self(t1); 209 const TypeClass* i2 = TypeClass::as_self(t2); 210 211 if (i1 == NULL || i2 == NULL) { 212 return TypeInt::CC; 213 } 214 215 if (t1->singleton() && t2->singleton()) { 216 NativeType val1 = i1->get_con(); 217 NativeType val2 = i2->get_con(); 218 if (node->will_overflow(val1, val2)) { 219 return TypeInt::CC; 220 } 221 return TypeInt::ZERO; 222 } else if (i1 != TypeClass::TYPE_DOMAIN && i2 != TypeClass::TYPE_DOMAIN) { 223 if (node->will_overflow(i1->_lo, i2->_lo)) { 224 return TypeInt::CC; 225 } else if (node->will_overflow(i1->_lo, i2->_hi)) { 226 return TypeInt::CC; 227 } else if (node->will_overflow(i1->_hi, i2->_lo)) { 228 return TypeInt::CC; 229 } else if (node->will_overflow(i1->_hi, i2->_hi)) { 230 return TypeInt::CC; 231 } 232 return TypeInt::ZERO; 233 } 234 235 if (!node->can_overflow(t1, t2)) { 236 return TypeInt::ZERO; 237 } 238 return TypeInt::CC; 239 } 240 }; 241 242 Node* OverflowINode::Ideal(PhaseGVN* phase, bool can_reshape) { 243 return IdealHelper<OverflowINode>::Ideal(this, phase, can_reshape); 244 } 245 246 Node* OverflowLNode::Ideal(PhaseGVN* phase, bool can_reshape) { 247 return IdealHelper<OverflowLNode>::Ideal(this, phase, can_reshape); 248 } 249 250 const Type* OverflowINode::Value(PhaseTransform* phase) const { 251 return IdealHelper<OverflowINode>::Value(this, phase); 252 } 253 254 const Type* OverflowLNode::Value(PhaseTransform* phase) const { 255 return IdealHelper<OverflowLNode>::Value(this, phase); 256 } 257