aoqi@0: /*
aoqi@0:  * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  *
aoqi@0:  */
aoqi@0: 
aoqi@0: #include "precompiled.hpp"
aoqi@0: #include "memory/allocation.inline.hpp"
aoqi@0: #include "opto/addnode.hpp"
aoqi@0: #include "opto/cfgnode.hpp"
aoqi@0: #include "opto/machnode.hpp"
aoqi@0: #include "opto/matcher.hpp"
aoqi@0: #include "opto/mathexactnode.hpp"
aoqi@0: #include "opto/subnode.hpp"
aoqi@0: 
aoqi@0: template <typename OverflowOp>
aoqi@0: class AddHelper {
aoqi@0: public:
aoqi@0:   typedef typename OverflowOp::TypeClass TypeClass;
aoqi@0:   typedef typename TypeClass::NativeType NativeType;
aoqi@0: 
aoqi@0:   static bool will_overflow(NativeType value1, NativeType value2) {
aoqi@0:     NativeType result = value1 + value2;
aoqi@0:     // Hacker's Delight 2-12 Overflow if both arguments have the opposite sign of the result
aoqi@0:     if (((value1 ^ result) & (value2 ^ result)) >= 0) {
aoqi@0:       return false;
aoqi@0:     }
aoqi@0:     return true;
aoqi@0:   }
aoqi@0: 
aoqi@0:   static bool can_overflow(const Type* type1, const Type* type2) {
aoqi@0:     if (type1 == TypeClass::ZERO || type2 == TypeClass::ZERO) {
aoqi@0:       return false;
aoqi@0:     }
aoqi@0:     return true;
aoqi@0:   }
aoqi@0: };
aoqi@0: 
aoqi@0: template <typename OverflowOp>
aoqi@0: class SubHelper {
aoqi@0: public:
aoqi@0:   typedef typename OverflowOp::TypeClass TypeClass;
aoqi@0:   typedef typename TypeClass::NativeType NativeType;
aoqi@0: 
aoqi@0:   static bool will_overflow(NativeType value1, NativeType value2) {
aoqi@0:     NativeType result = value1 - value2;
aoqi@0:     // hacker's delight 2-12 overflow iff the arguments have different signs and
aoqi@0:     // the sign of the result is different than the sign of arg1
aoqi@0:     if (((value1 ^ value2) & (value1 ^ result)) >= 0) {
aoqi@0:       return false;
aoqi@0:     }
aoqi@0:     return true;
aoqi@0:   }
aoqi@0: 
aoqi@0:   static bool can_overflow(const Type* type1, const Type* type2) {
aoqi@0:     if (type2 == TypeClass::ZERO) {
aoqi@0:       return false;
aoqi@0:     }
aoqi@0:     return true;
aoqi@0:   }
aoqi@0: };
aoqi@0: 
aoqi@0: template <typename OverflowOp>
aoqi@0: class MulHelper {
aoqi@0: public:
aoqi@0:   typedef typename OverflowOp::TypeClass TypeClass;
aoqi@0: 
aoqi@0:   static bool can_overflow(const Type* type1, const Type* type2) {
aoqi@0:     if (type1 == TypeClass::ZERO || type2 == TypeClass::ZERO) {
aoqi@0:       return false;
aoqi@0:     } else if (type1 == TypeClass::ONE || type2 == TypeClass::ONE) {
aoqi@0:       return false;
aoqi@0:     }
aoqi@0:     return true;
aoqi@0:   }
aoqi@0: };
aoqi@0: 
aoqi@0: bool OverflowAddINode::will_overflow(jint v1, jint v2) const {
aoqi@0:   return AddHelper<OverflowAddINode>::will_overflow(v1, v2);
aoqi@0: }
aoqi@0: 
aoqi@0: bool OverflowSubINode::will_overflow(jint v1, jint v2) const {
aoqi@0:   return SubHelper<OverflowSubINode>::will_overflow(v1, v2);
aoqi@0: }
aoqi@0: 
aoqi@0: bool OverflowMulINode::will_overflow(jint v1, jint v2) const {
aoqi@0:     jlong result = (jlong) v1 * (jlong) v2;
aoqi@0:     if ((jint) result == result) {
aoqi@0:       return false;
aoqi@0:     }
aoqi@0:     return true;
aoqi@0: }
aoqi@0: 
aoqi@0: bool OverflowAddLNode::will_overflow(jlong v1, jlong v2) const {
aoqi@0:   return AddHelper<OverflowAddLNode>::will_overflow(v1, v2);
aoqi@0: }
aoqi@0: 
aoqi@0: bool OverflowSubLNode::will_overflow(jlong v1, jlong v2) const {
aoqi@0:   return SubHelper<OverflowSubLNode>::will_overflow(v1, v2);
aoqi@0: }
aoqi@0: 
aoqi@0: bool OverflowMulLNode::will_overflow(jlong val1, jlong val2) const {
aoqi@0:     jlong result = val1 * val2;
aoqi@0:     jlong ax = (val1 < 0 ? -val1 : val1);
aoqi@0:     jlong ay = (val2 < 0 ? -val2 : val2);
aoqi@0: 
aoqi@0:     bool overflow = false;
aoqi@0:     if ((ax | ay) & CONST64(0xFFFFFFFF00000000)) {
aoqi@0:       // potential overflow if any bit in upper 32 bits are set
aoqi@0:       if ((val1 == min_jlong && val2 == -1) || (val2 == min_jlong && val1 == -1)) {
aoqi@0:         // -1 * Long.MIN_VALUE will overflow
aoqi@0:         overflow = true;
aoqi@0:       } else if (val2 != 0 && (result / val2 != val1)) {
aoqi@0:         overflow = true;
aoqi@0:       }
aoqi@0:     }
aoqi@0: 
aoqi@0:     return overflow;
aoqi@0: }
aoqi@0: 
aoqi@0: bool OverflowAddINode::can_overflow(const Type* t1, const Type* t2) const {
aoqi@0:   return AddHelper<OverflowAddINode>::can_overflow(t1, t2);
aoqi@0: }
aoqi@0: 
aoqi@0: bool OverflowSubINode::can_overflow(const Type* t1, const Type* t2) const {
aoqi@0:   if (in(1) == in(2)) {
aoqi@0:     return false;
aoqi@0:   }
aoqi@0:   return SubHelper<OverflowSubINode>::can_overflow(t1, t2);
aoqi@0: }
aoqi@0: 
aoqi@0: bool OverflowMulINode::can_overflow(const Type* t1, const Type* t2) const {
aoqi@0:   return MulHelper<OverflowMulINode>::can_overflow(t1, t2);
aoqi@0: }
aoqi@0: 
aoqi@0: bool OverflowAddLNode::can_overflow(const Type* t1, const Type* t2) const {
aoqi@0:   return AddHelper<OverflowAddLNode>::can_overflow(t1, t2);
aoqi@0: }
aoqi@0: 
aoqi@0: bool OverflowSubLNode::can_overflow(const Type* t1, const Type* t2) const {
aoqi@0:   if (in(1) == in(2)) {
aoqi@0:     return false;
aoqi@0:   }
aoqi@0:   return SubHelper<OverflowSubLNode>::can_overflow(t1, t2);
aoqi@0: }
aoqi@0: 
aoqi@0: bool OverflowMulLNode::can_overflow(const Type* t1, const Type* t2) const {
aoqi@0:   return MulHelper<OverflowMulLNode>::can_overflow(t1, t2);
aoqi@0: }
aoqi@0: 
aoqi@0: const Type* OverflowNode::sub(const Type* t1, const Type* t2) const {
aoqi@0:   fatal(err_msg_res("sub() should not be called for '%s'", NodeClassNames[this->Opcode()]));
aoqi@0:   return TypeInt::CC;
aoqi@0: }
aoqi@0: 
aoqi@0: template <typename OverflowOp>
aoqi@0: struct IdealHelper {
aoqi@0:   typedef typename OverflowOp::TypeClass TypeClass; // TypeInt, TypeLong
aoqi@0:   typedef typename TypeClass::NativeType NativeType;
aoqi@0: 
aoqi@0:   static Node* Ideal(const OverflowOp* node, PhaseGVN* phase, bool can_reshape) {
aoqi@0:     Node* arg1 = node->in(1);
aoqi@0:     Node* arg2 = node->in(2);
aoqi@0:     const Type* type1 = phase->type(arg1);
aoqi@0:     const Type* type2 = phase->type(arg2);
aoqi@0: 
aoqi@0:     if (type1 == NULL || type2 == NULL) {
aoqi@0:       return NULL;
aoqi@0:     }
aoqi@0: 
aoqi@0:     if (type1 != Type::TOP && type1->singleton() &&
aoqi@0:         type2 != Type::TOP && type2->singleton()) {
aoqi@0:       NativeType val1 = TypeClass::as_self(type1)->get_con();
aoqi@0:       NativeType val2 = TypeClass::as_self(type2)->get_con();
aoqi@0:       if (node->will_overflow(val1, val2) == false) {
aoqi@0:         Node* con_result = ConINode::make(phase->C, 0);
aoqi@0:         return con_result;
aoqi@0:       }
aoqi@0:       return NULL;
aoqi@0:     }
aoqi@0:     return NULL;
aoqi@0:   }
aoqi@0: 
aoqi@0:   static const Type* Value(const OverflowOp* node, PhaseTransform* phase) {
aoqi@0:     const Type *t1 = phase->type( node->in(1) );
aoqi@0:     const Type *t2 = phase->type( node->in(2) );
aoqi@0:     if( t1 == Type::TOP ) return Type::TOP;
aoqi@0:     if( t2 == Type::TOP ) return Type::TOP;
aoqi@0: 
aoqi@0:     const TypeClass* i1 = TypeClass::as_self(t1);
aoqi@0:     const TypeClass* i2 = TypeClass::as_self(t2);
aoqi@0: 
aoqi@0:     if (i1 == NULL || i2 == NULL) {
aoqi@0:       return TypeInt::CC;
aoqi@0:     }
aoqi@0: 
aoqi@0:     if (t1->singleton() && t2->singleton()) {
aoqi@0:       NativeType val1 = i1->get_con();
aoqi@0:       NativeType val2 = i2->get_con();
aoqi@0:       if (node->will_overflow(val1, val2)) {
aoqi@0:         return TypeInt::CC;
aoqi@0:       }
aoqi@0:       return TypeInt::ZERO;
aoqi@0:     } else if (i1 != TypeClass::TYPE_DOMAIN && i2 != TypeClass::TYPE_DOMAIN) {
aoqi@0:       if (node->will_overflow(i1->_lo, i2->_lo)) {
aoqi@0:         return TypeInt::CC;
aoqi@0:       } else if (node->will_overflow(i1->_lo, i2->_hi)) {
aoqi@0:         return TypeInt::CC;
aoqi@0:       } else if (node->will_overflow(i1->_hi, i2->_lo)) {
aoqi@0:         return TypeInt::CC;
aoqi@0:       } else if (node->will_overflow(i1->_hi, i2->_hi)) {
aoqi@0:         return TypeInt::CC;
aoqi@0:       }
aoqi@0:       return TypeInt::ZERO;
aoqi@0:     }
aoqi@0: 
aoqi@0:     if (!node->can_overflow(t1, t2)) {
aoqi@0:       return TypeInt::ZERO;
aoqi@0:     }
aoqi@0:     return TypeInt::CC;
aoqi@0:   }
aoqi@0: };
aoqi@0: 
aoqi@0: Node* OverflowINode::Ideal(PhaseGVN* phase, bool can_reshape) {
aoqi@0:   return IdealHelper<OverflowINode>::Ideal(this, phase, can_reshape);
aoqi@0: }
aoqi@0: 
aoqi@0: Node* OverflowLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
aoqi@0:   return IdealHelper<OverflowLNode>::Ideal(this, phase, can_reshape);
aoqi@0: }
aoqi@0: 
aoqi@0: const Type* OverflowINode::Value(PhaseTransform* phase) const {
aoqi@0:   return IdealHelper<OverflowINode>::Value(this, phase);
aoqi@0: }
aoqi@0: 
aoqi@0: const Type* OverflowLNode::Value(PhaseTransform* phase) const {
aoqi@0:   return IdealHelper<OverflowLNode>::Value(this, phase);
aoqi@0: }
aoqi@0: