Mercurial > hg > truffle

comparison src/share/vm/opto/mathexactnode.cpp @ 12323:c9ccd7b85f20

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
8024924: Intrinsify java.lang.Math.addExact Reviewed-by: kvn, twisti
author rbackman
date Fri, 27 Sep 2013 08:39:19 +0200
parents
children 4a2acfb16e97
comparison
equal deleted inserted replaced
12322:72b7e96c1922 12323:c9ccd7b85f20
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/machnode.hpp"
29 #include "opto/mathexactnode.hpp"
30 #include "opto/matcher.hpp"
31 #include "opto/subnode.hpp"
32
33 MathExactNode::MathExactNode(Node* ctrl, Node* n1, Node* n2) : MultiNode(3) {
34 init_req(0, ctrl);
35 init_req(1, n1);
36 init_req(2, n2);
37 }
38
39 Node* AddExactINode::match(const ProjNode* proj, const Matcher* m) {
40 uint ideal_reg = proj->ideal_reg();
41 RegMask rm;
42 if (proj->_con == result_proj_node) {
43 rm = m->mathExactI_result_proj_mask();
44 } else {
45 assert(proj->_con == flags_proj_node, "must be result or flags");
46 assert(ideal_reg == Op_RegFlags, "sanity");
47 rm = m->mathExactI_flags_proj_mask();
48 }
49 return new (m->C) MachProjNode(this, proj->_con, rm, ideal_reg);
50 }
51
52 // If the MathExactNode won't overflow we have to replace the
53 // FlagsProjNode and ProjNode that is generated by the MathExactNode
54 Node* MathExactNode::no_overflow(PhaseGVN *phase, Node* new_result) {
55 PhaseIterGVN *igvn = phase->is_IterGVN();
56 if (igvn) {
57 ProjNode* result = result_node();
58 ProjNode* flags = flags_node();
59
60 if (result != NULL) {
61 igvn->replace_node(result, new_result);
62 }
63
64 if (flags != NULL) {
65 BoolNode* bolnode = (BoolNode *) flags->unique_out();
66 switch (bolnode->_test._test) {
67 case BoolTest::overflow:
68 // if the check is for overflow - never taken
69 igvn->replace_node(bolnode, phase->intcon(0));
70 break;
71 case BoolTest::no_overflow:
72 // if the check is for no overflow - always taken
73 igvn->replace_node(bolnode, phase->intcon(1));
74 break;
75 default:
76 fatal("Unexpected value of BoolTest");
77 break;
78 }
79 flags->del_req(0);
80 }
81 }
82 return new_result;
83 }
84
85 Node *AddExactINode::Ideal(PhaseGVN *phase, bool can_reshape) {
86 Node *arg1 = in(1);
87 Node *arg2 = in(2);
88
89 const Type* type1 = phase->type(arg1);
90 const Type* type2 = phase->type(arg2);
91
92 if (type1 != Type::TOP && type1->singleton() &&
93 type2 != Type::TOP && type2->singleton()) {
94 jint val1 = arg1->get_int();
95 jint val2 = arg2->get_int();
96 jint result = val1 + val2;
97 // Hacker's Delight 2-12 Overflow if both arguments have the opposite sign of the result
98 if ( (((val1 ^ result) & (val2 ^ result)) >= 0)) {
99 Node* con_result = ConINode::make(phase->C, result);
100 return no_overflow(phase, con_result);
101 }
102 return NULL;
103 }
104
105 if (type1 == TypeInt::ZERO) { // (Add 0 x) == x
106 Node* add_result = new (phase->C) AddINode(arg1, arg2);
107 return no_overflow(phase, add_result);
108 }
109
110 if (type2 == TypeInt::ZERO) { // (Add x 0) == x
111 Node* add_result = new (phase->C) AddINode(arg1, arg2);
112 return no_overflow(phase, add_result);
113 }
114
115 if (type2->singleton()) {
116 return NULL; // no change - keep constant on the right
117 }
118
119 if (type1->singleton()) {
120 // Make it x + Constant - move constant to the right
121 swap_edges(1, 2);
122 return this;
123 }
124
125 if (arg2->is_Load()) {
126 return NULL; // no change - keep load on the right
127 }
128
129 if (arg1->is_Load()) {
130 // Make it x + Load - move load to the right
131 swap_edges(1, 2);
132 return this;
133 }
134
135 if (arg1->_idx > arg2->_idx) {
136 // Sort the edges
137 swap_edges(1, 2);
138 return this;
139 }
140
141 return NULL;
142 }
143