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 "opto/opaquenode.hpp"
27 #include "opto/phaseX.hpp"
28
29 //=============================================================================
30 // Do not allow value-numbering
31 uint Opaque1Node::hash() const { return NO_HASH; }
32 uint Opaque1Node::cmp( const Node &n ) const {
33 return (&n == this); // Always fail except on self
34 }
35
36 //------------------------------Identity---------------------------------------
37 // If _major_progress, then more loop optimizations follow. Do NOT remove
38 // the opaque Node until no more loop ops can happen. Note the timing of
39 // _major_progress; it's set in the major loop optimizations THEN comes the
40 // call to IterGVN and any chance of hitting this code. Hence there's no
41 // phase-ordering problem with stripping Opaque1 in IGVN followed by some
42 // more loop optimizations that require it.
43 Node *Opaque1Node::Identity( PhaseTransform *phase ) {
44 return phase->C->major_progress() ? this : in(1);
45 }
46
47 //=============================================================================
48 // A node to prevent unwanted optimizations. Allows constant folding. Stops
49 // value-numbering, most Ideal calls or Identity functions. This Node is
50 // specifically designed to prevent the pre-increment value of a loop trip
51 // counter from being live out of the bottom of the loop (hence causing the
52 // pre- and post-increment values both being live and thus requiring an extra
53 // temp register and an extra move). If we "accidentally" optimize through
54 // this kind of a Node, we'll get slightly pessimal, but correct, code. Thus
55 // it's OK to be slightly sloppy on optimizations here.
56
57 // Do not allow value-numbering
58 uint Opaque2Node::hash() const { return NO_HASH; }
59 uint Opaque2Node::cmp( const Node &n ) const {
60 return (&n == this); // Always fail except on self
61 }
62
63
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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 "opto/loopnode.hpp"
27 #include "opto/opaquenode.hpp"
28 #include "opto/phaseX.hpp"
29
30 //=============================================================================
31 // Do not allow value-numbering
32 uint Opaque1Node::hash() const { return NO_HASH; }
33 uint Opaque1Node::cmp(const Node &n) const {
34 return (&n == this); // Always fail except on self
35 }
36
37 //------------------------------Identity---------------------------------------
38 // If _major_progress, then more loop optimizations follow. Do NOT remove
39 // the opaque Node until no more loop ops can happen. Note the timing of
40 // _major_progress; it's set in the major loop optimizations THEN comes the
41 // call to IterGVN and any chance of hitting this code. Hence there's no
42 // phase-ordering problem with stripping Opaque1 in IGVN followed by some
43 // more loop optimizations that require it.
44 Node *Opaque1Node::Identity(PhaseTransform *phase) {
45 return phase->C->major_progress() ? this : in(1);
46 }
47
48 Node *Opaque1Node::Ideal(PhaseGVN *phase, bool can_reshape) {
49 if (!phase->C->major_progress() && outcnt() > 0) {
50 assert(can_reshape, "loop opts over but not IGVN?");
51 if (raw_out(0)->Opcode() == Op_CmpI) {
52 Node* cmp = raw_out(0);
53 if (cmp->in(1)->Opcode() == Op_AddI) {
54 Node *add = cmp->in(1);
55 if (add->in(1)->is_Phi()) {
56 Node* phi = add->in(1);
57 if (phi->in(0)->is_CountedLoop()) {
58 CountedLoopNode* cl = phi->in(0)->as_CountedLoop();
59 if (cl->phi() == phi) {
60 // If this opaque node feeds into the limit condition of
61 // a CountedLoop, we need to process the Phi node for
62 // the induction variable: the range of values taken by
63 // the Phi is known now and so its type is also known.
64 phase->is_IterGVN()->_worklist.push(phi);
65 }
66 }
67 }
68 }
69 Node* in1 = cmp->in(1);
70 for (uint i = 0; i < in1->outcnt(); i++) {
71 if (in1->raw_out(i)->Opcode() == Op_CastII) {
72 Node* castii = in1->raw_out(i);
73 if (castii->in(0) != NULL && castii->in(0)->in(0) != NULL && castii->in(0)->in(0)->is_If()) {
74 Node* ifnode = castii->in(0)->in(0);
75 if (ifnode->in(1) != NULL && ifnode->in(1)->in(1) == cmp) {
76 // Reprocess a CastII node that may depend on this
77 // opaque node value in case it's inexact and we can do
78 // a better job of setting its type.
79 phase->is_IterGVN()->_worklist.push(castii);
80 }
81 }
82 }
83 }
84 }
85 }
86 return NULL;
87 }
88
89 //=============================================================================
90 // A node to prevent unwanted optimizations. Allows constant folding. Stops
91 // value-numbering, most Ideal calls or Identity functions. This Node is
92 // specifically designed to prevent the pre-increment value of a loop trip
93 // counter from being live out of the bottom of the loop (hence causing the
94 // pre- and post-increment values both being live and thus requiring an extra
95 // temp register and an extra move). If we "accidentally" optimize through
96 // this kind of a Node, we'll get slightly pessimal, but correct, code. Thus
97 // it's OK to be slightly sloppy on optimizations here.
98
99 // Do not allow value-numbering
100 uint Opaque2Node::hash() const { return NO_HASH; }
101 uint Opaque2Node::cmp( const Node &n ) const {
102 return (&n == this); // Always fail except on self
103 }
104
105
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