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8240905: assert(mem == (Node*)1 || mem == mem2) failed: multiple Memo…

…ries being matched at once?

Stop recursion if there are multiple loads with different memory inputs in the tree.

Reviewed-by: kvn, vlivanov
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TobiHartmann committed Mar 24, 2020
1 parent d01f671 commit ca85500615c56e5890b72fab7c76d817eb2a76b3
@@ -1359,7 +1359,8 @@ MachNode *Matcher::match_tree( const Node *n ) {
s->_kids[1] = NULL;
s->_leaf = (Node*)n;
// Label the input tree, allocating labels from top-level arena
Label_Root( n, s, n->in(0), mem );
Node* root_mem = mem;
Label_Root(n, s, n->in(0), root_mem);
if (C->failing()) return NULL;

// The minimum cost match for the whole tree is found at the root State
@@ -1473,8 +1474,9 @@ static bool match_into_reg( const Node *n, Node *m, Node *control, int i, bool s
// Store and the Load must have identical Memories (as well as identical
// pointers). Since the Matcher does not have anything for Memory (and
// does not handle DAGs), I have to match the Memory input myself. If the
// Tree root is a Store, I require all Loads to have the identical memory.
Node *Matcher::Label_Root( const Node *n, State *svec, Node *control, const Node *mem){
// Tree root is a Store or if there are multiple Loads in the tree, I require
// all Loads to have the identical memory.
Node* Matcher::Label_Root(const Node* n, State* svec, Node* control, Node*& mem) {
// Since Label_Root is a recursive function, its possible that we might run
// out of stack space. See bugs 6272980 & 6227033 for more info.
LabelRootDepth++;
@@ -1498,6 +1500,11 @@ Node *Matcher::Label_Root( const Node *n, State *svec, Node *control, const Node
if( m->is_Load() ) {
if( input_mem == NULL ) {
input_mem = m->in(MemNode::Memory);
if (mem == (Node*)1) {
// Save this memory to bail out if there's another memory access
// to a different memory location in the same tree.
mem = input_mem;
}
} else if( input_mem != m->in(MemNode::Memory) ) {
input_mem = NodeSentinel;
}
@@ -1521,16 +1528,16 @@ Node *Matcher::Label_Root( const Node *n, State *svec, Node *control, const Node
// the current tree. If it finds any, that value is matched as a
// register operand. If not, then the normal matching is used.
if( match_into_reg(n, m, control, i, is_shared(m)) ||
//
// Stop recursion if this is LoadNode and the root of this tree is a
// StoreNode and the load & store have different memories.
// Stop recursion if this is a LoadNode and there is another memory access
// to a different memory location in the same tree (for example, a StoreNode
// at the root of this tree or another LoadNode in one of the children).
((mem!=(Node*)1) && m->is_Load() && m->in(MemNode::Memory) != mem) ||
// Can NOT include the match of a subtree when its memory state
// is used by any of the other subtrees
(input_mem == NodeSentinel) ) {
// Print when we exclude matching due to different memory states at input-loads
if (PrintOpto && (Verbose && WizardMode) && (input_mem == NodeSentinel)
&& !((mem!=(Node*)1) && m->is_Load() && m->in(MemNode::Memory) != mem)) {
&& !((mem!=(Node*)1) && m->is_Load() && m->in(MemNode::Memory) != mem)) {
tty->print_cr("invalid input_mem");
}
// Switch to a register-only opcode; this value must be in a register
@@ -1542,7 +1549,7 @@ Node *Matcher::Label_Root( const Node *n, State *svec, Node *control, const Node
if( control == NULL && m->in(0) != NULL && m->req() > 1 )
control = m->in(0); // Pick up control
// Else match as a normal part of the match tree.
control = Label_Root(m,s,control,mem);
control = Label_Root(m, s, control, mem);
if (C->failing()) return NULL;
}
}
@@ -131,7 +131,7 @@ class Matcher : public PhaseTransform {
GrowableArray<Node_Notes*>* _old_node_note_array;

// Node labeling iterator for instruction selection
Node *Label_Root( const Node *n, State *svec, Node *control, const Node *mem );
Node* Label_Root(const Node* n, State* svec, Node* control, Node*& mem);

Node *transform( Node *dummy );

@@ -0,0 +1,122 @@
/*
* Copyright (c) 2020, 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.
*/

/*
* @test
* @bug 8240905
* @summary Test matching of instructions that have multiple memory inputs.
* @run main/othervm -Xbatch -XX:-TieredCompilation
* compiler.codegen.TestMultiMemInstructionMatching
*/

package compiler.codegen;

public class TestMultiMemInstructionMatching {

static volatile int iFldV = 42;
static volatile long lFldV = 42;
static int iFld = 42;
static long lFld = 42;

// Integer versions

static int test_blsiI_rReg_mem_1() {
return (0 - iFldV) & iFldV;
}

static int test_blsiI_rReg_mem_2() {
int sub = (0 - iFld);
iFldV++;
return sub & iFld;
}

static int test_blsrI_rReg_mem_1() {
return (iFldV - 1) & iFldV;
}

static int test_blsrI_rReg_mem_2() {
int sub = (iFld - 1);
iFldV++;
return sub & iFld;
}

static int test_blsmskI_rReg_mem_1() {
return (iFldV - 1) ^ iFldV;
}

static int test_blsmskI_rReg_mem_2() {
int sub = (iFld - 1);
iFldV++;
return sub ^ iFld;
}

// Long versions

static long test_blsiL_rReg_mem_1() {
return (0 - lFldV) & lFldV;
}

static long test_blsiL_rReg_mem_2() {
long sub = (0 - lFld);
lFldV++;
return sub & lFld;
}

static long test_blsrL_rReg_mem_1() {
return (lFldV - 1) & lFldV;
}

static long test_blsrL_rReg_mem_2() {
long sub = (lFld - 1);
lFldV++;
return sub & lFld;
}

static long test_blsmskL_rReg_mem_1() {
return (lFldV - 1) ^ lFldV;
}

static long test_blsmskL_rReg_mem_2() {
long sub = (lFld - 1);
lFldV++;
return sub ^ lFld;
}

public static void main(String[] args) {
for (int i = 0;i < 100_000;++i) {
test_blsiI_rReg_mem_1();
test_blsiI_rReg_mem_2();
test_blsrI_rReg_mem_1();
test_blsrI_rReg_mem_2();
test_blsmskI_rReg_mem_1();
test_blsmskI_rReg_mem_2();

test_blsiL_rReg_mem_1();
test_blsiL_rReg_mem_2();
test_blsrL_rReg_mem_1();
test_blsrL_rReg_mem_2();
test_blsmskL_rReg_mem_1();
test_blsmskL_rReg_mem_2();
}
}
}

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