8288683: C2: And node gets wrong type due to not adding it back to the worklist in CCP

Reviewed-by: roland, thartmann
This commit is contained in:
Christian Hagedorn 2022-06-27 11:32:13 +00:00
parent 7e13cdb799
commit 784a0f0496
3 changed files with 110 additions and 0 deletions

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@ -1861,6 +1861,24 @@ void PhaseCCP::analyze() {
}
}
}
push_and(worklist, n, m);
}
}
}
}
// AndI/L::Value() optimizes patterns similar to (v << 2) & 3 to zero if they are bitwise disjoint.
// Add the AndI/L nodes back to the worklist to re-apply Value() in case the shift value changed.
void PhaseCCP::push_and(Unique_Node_List& worklist, const Node* parent, const Node* use) const {
uint use_op = use->Opcode();
if ((use_op == Op_LShiftI || use_op == Op_LShiftL)
&& use->in(2) == parent) { // is shift value (right-hand side of LShift)
for (DUIterator_Fast imax, i = use->fast_outs(imax); i < imax; i++) {
Node* and_node = use->fast_out(i);
uint and_node_op = and_node->Opcode();
if ((and_node_op == Op_AndI || and_node_op == Op_AndL)
&& and_node->bottom_type() != type(and_node)) {
worklist.push(and_node);
}
}
}

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@ -568,6 +568,8 @@ class PhaseCCP : public PhaseIterGVN {
// Non-recursive. Use analysis to transform single Node.
virtual Node *transform_once( Node *n );
void push_and(Unique_Node_List& worklist, const Node* parent, const Node* use) const;
public:
PhaseCCP( PhaseIterGVN *igvn ); // Compute conditional constants
NOT_PRODUCT( ~PhaseCCP(); )

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@ -0,0 +1,90 @@
/*
* Copyright (c) 2022, 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 8288683
* @library /test/lib
* @summary Test that And nodes are added to the CCP worklist if they have an LShift as input.
* @run main/othervm -Xbatch compiler.c2.TestAndShiftZeroCCP
*/
package compiler.c2;
import jdk.test.lib.Asserts;
public class TestAndShiftZeroCCP {
static int iFld = 0xfffff;
public static void main(String[] strArr) {
for (int i = 0; i < 10000; i++) {
Asserts.assertEQ(testAndI(), 224);
Asserts.assertEQ(testAndL(), 224L);
Asserts.assertEQ(testAndLConvI2L(), 224L);
}
}
static int testAndI() {
int x = 10;
int y = iFld;
int z = 3;
int q;
for (int i = 62; i < 70; ++i) {
q = y << i;
for (int j = 0; j < 8; j++) {
z += i;
}
z = q & 0xff;
}
return z;
}
static long testAndL() {
long x = 10;
long y = iFld;
long z = 3;
long q;
for (int i = 62; i < 70; ++i) {
q = y << i;
for (int j = 0; j < 8; j++) {
z += i;
}
z = q & 0xff;
}
return z;
}
static long testAndLConvI2L() {
long x = 10;
long y = iFld;
long z = 3;
long q;
for (int i = 62; i < 70; ++i) {
q = y << i;
for (int j = 0; j < 8; j++) {
z += i;
}
z = q & 0xff;
}
return z;
}
}