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/*
* 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.
*/
package compiler.c2.irTests;
import jdk.test.lib.Asserts;
import compiler.lib.ir_framework.*;
/*
* @test
* @bug 8267265
* @summary Test that Ideal transformations of DivLNode* are being performed as expected.
* @library /test/lib /
* @run driver compiler.c2.irTests.DivLNodeIdealizationTests
*/
public class DivLNodeIdealizationTests {
public static void main(String[] args) {
TestFramework.run();
}
@Run(test = {"constant", "identity", "identityAgain", "identityThird",
"retainDenominator", "divByNegOne", "divByPow2And",
"divByPow2And1", "divByPow2", "divByNegPow2"})
public void runMethod() {
long a = RunInfo.getRandom().nextLong();
a = (a == 0) ? 1 : a;
long b = RunInfo.getRandom().nextLong();
b = (b == 0) ? 1 : b;
long min = Long.MIN_VALUE;
long max = Long.MAX_VALUE;
assertResult(0, 0, true);
assertResult(a, b, false);
assertResult(min, min, false);
assertResult(max, max, false);
}
@DontCompile
public void assertResult(long a, long b, boolean shouldThrow) {
try {
Asserts.assertEQ(a / a, constant(a));
Asserts.assertFalse(shouldThrow, "Expected an exception to be thrown.");
}
catch (ArithmeticException e) {
Asserts.assertTrue(shouldThrow, "Did not expected an exception to be thrown.");
}
try {
Asserts.assertEQ((a * b) / b, retainDenominator(a, b));
Asserts.assertFalse(shouldThrow, "Expected an exception to be thrown.");
}
catch (ArithmeticException e) {
Asserts.assertTrue(shouldThrow, "Did not expected an exception to be thrown.");
}
try {
Asserts.assertEQ(a / (b / b), identityThird(a, b));
Asserts.assertFalse(shouldThrow, "Expected an exception to be thrown.");
}
catch (ArithmeticException e) {
Asserts.assertTrue(shouldThrow, "Did not expected an exception to be thrown.");
}
Asserts.assertEQ(a / 1 , identity(a));
Asserts.assertEQ(a / (13 / 13), identityAgain(a));
Asserts.assertEQ(a / -1 , divByNegOne(a));
Asserts.assertEQ((a & -4) / 2 , divByPow2And(a));
Asserts.assertEQ((a & -2) / 2 , divByPow2And1(a));
Asserts.assertEQ(a / 8 , divByPow2(a));
Asserts.assertEQ(a / -8 , divByNegPow2(a));
}
@Test
@IR(failOn = {IRNode.DIV})
@IR(counts = {IRNode.DIV_BY_ZERO_TRAP, "1"})
// Checks x / x => 1
public long constant(long x) {
return x / x;
}
@Test
@IR(failOn = {IRNode.DIV})
// Checks x / 1 => x
public long identity(long x) {
return x / 1L;
}
@Test
@IR(failOn = {IRNode.DIV})
// Checks x / (c / c) => x
public long identityAgain(long x) {
return x / (13L / 13L);
}
@Test
@IR(failOn = {IRNode.DIV})
@IR(counts = {IRNode.DIV_BY_ZERO_TRAP, "1"})
// Checks x / (y / y) => x
public long identityThird(long x, long y) {
return x / (y / y);
}
@Test
@IR(counts = {IRNode.MUL_L, "1",
IRNode.DIV_L, "1",
IRNode.DIV_BY_ZERO_TRAP, "1"
})
public long retainDenominator(long x, long y) {
return (x * y) / y;
}
@Test
@IR(failOn = {IRNode.DIV})
@IR(counts = {IRNode.SUB, "1"})
// Checks x / -1 => 0 - x
public long divByNegOne(long x) {
return x / -1L;
}
@Test
@IR(failOn = {IRNode.DIV})
@IR(counts = {IRNode.AND, "1",
IRNode.RSHIFT, "1",
})
// Checks (x & -(2^c0)) / 2^c1 => (x >> c1) & (2^c0 >> c1) => (x >> c1) & c3 where 2^c0 > |2^c1| "and" c3 = 2^c0 >> c1
// Having a large enough and in the dividend removes the need to account for
// rounding when converting to shifts and multiplies as in divByPow2()
public long divByPow2And(long x) {
return (x & -4L) / 2L;
}
@Test
@IR(failOn = {IRNode.DIV, IRNode.AND})
@IR(counts = {IRNode.RSHIFT, "1"})
// Checks (x & -(2^c0)) / 2^c0 => x >> c0
// If the negative of the constant within the & equals the divisor then
// the and can be removed as it only affects bits that will be shifted off
public long divByPow2And1(long x) {
return (x & -2L) / 2L;
}
@Test
@IR(failOn = {IRNode.DIV})
@IR(counts = {IRNode.URSHIFT, "1",
IRNode.RSHIFT, "2",
IRNode.ADD, "1",
})
// Checks x / 2^c0 => x + ((x >>)ith negative numbers. Since x may be negative
// in this method, an additional add, logical right shift, and signed shift
// are needed to account for rounding.
public long divByPow2(long x) {
return x / 8L;
}
@Test
@IR(failOn = {IRNode.DIV})
@IR(counts = {IRNode.URSHIFT, "1",
IRNode.RSHIFT, "2",
IRNode.ADD, "1",
IRNode.SUB, "1",
})
// Checks x / -(2^c0) =>0 - (x + ((x >> (32-1)) >>> (32 - c0)) >> c0) => 0 - (x + ((x >> 31) >>> c1) >> c0) where c1 = 32 - c0
// Similar to divByPow2() except a negative divisor turns positive.
// After the transformations, 0 is subtracted by the whole expression
// to account for the negative.
public long divByNegPow2(long x) {
return x / -8L;
}
}
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