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2 changes: 1 addition & 1 deletion src/hotspot/share/opto/loopPredicate.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -469,7 +469,7 @@ class Invariance : public StackObj {
// loop, it was marked invariant but n is only invariant if
// it depends only on that test. Otherwise, unless that test
// is out of the loop, it's not invariant.
if (n->is_CFG() || n->depends_only_on_test() || n->in(0) == nullptr || !_phase->is_member(_lpt, n->in(0))) {
if (n->is_CFG() || (n->depends_only_on_test() && _phase->igvn().no_dependent_zero_check(n)) || n->in(0) == nullptr || !_phase->is_member(_lpt, n->in(0))) {
_invariant.set(n->_idx); // I am a invariant too
}
}
Expand Down
Original file line number Diff line number Diff line change
@@ -0,0 +1,89 @@
/*
* Copyright (c) 2024, 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 8331717
* @summary C2: Crash with SIGFPE
*
* @run main/othervm -XX:CompileCommand=compileonly,*TestLoopPredicationDivZeroCheck*::* -XX:-TieredCompilation -Xbatch TestLoopPredicationDivZeroCheck
*/

public class TestLoopPredicationDivZeroCheck {
static int iArr[] = new int[100];
static volatile long lFld;
static int iFld;

public static void main(String[] strArr) {
for (int i = 0; i < 10000; i++) {
test();
}
for (int i = 0; i < 10000; i++) {
test2();
}
}

/*
* The division 2 / i4 requires a non-zero check. As the result is an array access, it will be the input to a range
* check. Loop predication will try to move the range check and the division to right before the loop as the division
* appears to be invariant (i4 is always 0). However, the division is not truly invariant as it requires the zero
* check for i4 that can throw an exception. The bug fixed in 8331717 caused the division to still be moved before the
* for loop with the range check.
*/
static void test() {
int i1 = 0;

for (int i4 : iArr) {
i4 = i1;
try {
iArr[0] = 1 / i4;
i4 = iArr[2 / i4];
} catch (ArithmeticException a_e) {
}
}
}

/*
* Loop predication will try to move 3 / y (input to the range check for bArr[x / 30]) before its containing for loop
* but it may not as y must be zero-checked. The same problem as above occurred before the fix in 8331717.
*/
static void test2() {
int x = 0;
int y = iFld;
long lArr[] = new long[400];
boolean bArr[] = new boolean[400];
for (int i = 0; i < 10000; i++) {
for (int j = 1; j < 13; j++) {
for (int k = 1; k < 2; k++) {
lFld = 0;
lArr[1] = 7;
try {
x = 3 / y;
} catch (ArithmeticException a_e) {
}
bArr[x / 30] = true;
}
}
}
}
}