Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  *

  */

 #include "precompiled.hpp"

 #include "memory/allocation.inline.hpp"

 #include "opto/addnode.hpp"

 #include "opto/cfgnode.hpp"

 #include "opto/machnode.hpp"

 #include "opto/matcher.hpp"

 #include "opto/mathexactnode.hpp"

 #include "opto/subnode.hpp"

 MathExactNode::MathExactNode(Node* ctrl, Node* n1, Node* n2) : MultiNode(3) {

   init_req(0, ctrl);

   init_req(1, n1);

   init_req(2, n2);

 }

 BoolNode* MathExactNode::bool_node() const {

   Node* flags = flags_node();

   BoolNode* boolnode = flags->unique_out()->as_Bool();

   assert(boolnode != NULL, "must have BoolNode");

   return boolnode;

 }

 IfNode* MathExactNode::if_node() const {

   BoolNode* boolnode = bool_node();

   IfNode* ifnode = boolnode->unique_out()->as_If();

   assert(ifnode != NULL, "must have IfNode");

   return ifnode;

 }

 Node* MathExactNode::control_node() const {

   IfNode* ifnode = if_node();

   return ifnode->in(0);

 }

 Node* MathExactNode::non_throwing_branch() const {

   IfNode* ifnode = if_node();

   if (bool_node()->_test._test == BoolTest::overflow) {

     return ifnode->proj_out(0);

   }

   return ifnode->proj_out(1);

 }

 Node* AddExactINode::match(const ProjNode* proj, const Matcher* m) {

   uint ideal_reg = proj->ideal_reg();

   RegMask rm;

   if (proj->_con == result_proj_node) {

     rm = m->mathExactI_result_proj_mask();

   } else {

     assert(proj->_con == flags_proj_node, "must be result or flags");

     assert(ideal_reg == Op_RegFlags, "sanity");

     rm = m->mathExactI_flags_proj_mask();

   }

   return new (m->C) MachProjNode(this, proj->_con, rm, ideal_reg);

 }

 // If the MathExactNode won't overflow we have to replace the

 // FlagsProjNode and ProjNode that is generated by the MathExactNode

 Node* MathExactNode::no_overflow(PhaseGVN *phase, Node* new_result) {

   PhaseIterGVN *igvn = phase->is_IterGVN();

   if (igvn) {

     ProjNode* result = result_node();

     ProjNode* flags = flags_node();

     if (result != NULL) {

       igvn->replace_node(result, new_result);

     }

     if (flags != NULL) {

       BoolNode* boolnode = bool_node();

       switch (boolnode->_test._test) {

         case BoolTest::overflow:

           // if the check is for overflow - never taken

           igvn->replace_node(boolnode, phase->intcon(0));

           break;

         case BoolTest::no_overflow:

           // if the check is for no overflow - always taken

           igvn->replace_node(boolnode, phase->intcon(1));

           break;

         default:

           fatal("Unexpected value of BoolTest");

           break;

       }

       flags->del_req(0);

     }

   }

   return new_result;

 }

 Node *AddExactINode::Ideal(PhaseGVN *phase, bool can_reshape) {

   Node *arg1 = in(1);

   Node *arg2 = in(2);

   const Type* type1 = phase->type(arg1);

   const Type* type2 = phase->type(arg2);

   if (type1 != Type::TOP && type1->singleton() &&

       type2 != Type::TOP && type2->singleton()) {

     jint val1 = arg1->get_int();

     jint val2 = arg2->get_int();

     jint result = val1 + val2;

     // Hacker's Delight 2-12 Overflow if both arguments have the opposite sign of the result

     if ( (((val1 ^ result) & (val2 ^ result)) >= 0)) {

       Node* con_result = ConINode::make(phase->C, result);

       return no_overflow(phase, con_result);

     }

     return NULL;

   }

   if (type1 == TypeInt::ZERO) { // (Add 0 x) == x

     Node* add_result = new (phase->C) AddINode(arg1, arg2);

     return no_overflow(phase, add_result);

   }

   if (type2 == TypeInt::ZERO) { // (Add x 0) == x

     Node* add_result = new (phase->C) AddINode(arg1, arg2);

     return no_overflow(phase, add_result);

   }

   if (type2->singleton()) {

     return NULL; // no change - keep constant on the right

   }

   if (type1->singleton()) {

     // Make it x + Constant - move constant to the right

     swap_edges(1, 2);

     return this;

   }

   if (arg2->is_Load()) {

     return NULL; // no change - keep load on the right

   }

   if (arg1->is_Load()) {

     // Make it x + Load - move load to the right

     swap_edges(1, 2);

     return this;

   }

   if (arg1->_idx > arg2->_idx) {

     // Sort the edges

     swap_edges(1, 2);

     return this;

   }

   return NULL;

 }