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8320330: Improve implementation of RShift Value

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Reviewed-by: thartmann, chagedorn
This commit is contained in:
Jasmine Karthikeyan 2023-11-27 14:44:08 +00:00 committed by Tobias Hartmann
parent a40d8d97e8
commit 4977922a3f
3 changed files with 214 additions and 11 deletions
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39
src/hotspot/share/opto/mulnode.cpp
View File

@ -1297,15 +1297,12 @@ const Type* RShiftINode::Value(PhaseGVN* phase) const {
if (t1 == Type::BOTTOM || t2 == Type::BOTTOM)
return TypeInt::INT;
if (t2 == TypeInt::INT)
return TypeInt::INT;
const TypeInt *r1 = t1->is_int(); // Handy access
const TypeInt *r2 = t2->is_int(); // Handy access
// If the shift is a constant, just shift the bounds of the type.
// For example, if the shift is 31, we just propagate sign bits.
if (r2->is_con()) {
if (!r1->is_con() && r2->is_con()) {
uint shift = r2->get_con();
shift &= BitsPerJavaInteger-1; // semantics of Java shifts
// Shift by a multiple of 32 does nothing:
@ -1327,8 +1324,19 @@ const Type* RShiftINode::Value(PhaseGVN* phase) const {
return ti;
}
if( !r1->is_con() || !r2->is_con() )
if (!r1->is_con() || !r2->is_con()) {
// If the left input is non-negative the result must also be non-negative, regardless of what the right input is.
if (r1->_lo >= 0) {
return TypeInt::make(0, r1->_hi, MAX2(r1->_widen, r2->_widen));
}
// Conversely, if the left input is negative then the result must be negative.
if (r1->_hi <= -1) {
return TypeInt::make(r1->_lo, -1, MAX2(r1->_widen, r2->_widen));
}
return TypeInt::INT;
}
// Signed shift right
return TypeInt::make(r1->get_con() >> (r2->get_con() & 31));
@ -1359,15 +1367,12 @@ const Type* RShiftLNode::Value(PhaseGVN* phase) const {
if (t1 == Type::BOTTOM || t2 == Type::BOTTOM)
return TypeLong::LONG;
if (t2 == TypeInt::INT)
return TypeLong::LONG;
const TypeLong *r1 = t1->is_long(); // Handy access
const TypeInt *r2 = t2->is_int (); // Handy access
// If the shift is a constant, just shift the bounds of the type.
// For example, if the shift is 63, we just propagate sign bits.
if (r2->is_con()) {
if (!r1->is_con() && r2->is_con()) {
uint shift = r2->get_con();
shift &= (2*BitsPerJavaInteger)-1; // semantics of Java shifts
// Shift by a multiple of 64 does nothing:
@ -1389,7 +1394,21 @@ const Type* RShiftLNode::Value(PhaseGVN* phase) const {
return tl;
}
return TypeLong::LONG; // Give up
if (!r1->is_con() || !r2->is_con()) {
// If the left input is non-negative the result must also be non-negative, regardless of what the right input is.
if (r1->_lo >= 0) {
return TypeLong::make(0, r1->_hi, MAX2(r1->_widen, r2->_widen));
}
// Conversely, if the left input is negative then the result must be negative.
if (r1->_hi <= -1) {
return TypeLong::make(r1->_lo, -1, MAX2(r1->_widen, r2->_widen));
}
return TypeLong::LONG;
}
return TypeLong::make(r1->get_con() >> (r2->get_con() & 63));
}
//=============================================================================

92
test/hotspot/jtreg/compiler/c2/irTests/RShiftINodeIdealizationTests.java Normal file
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@ -0,0 +1,92 @@
/*
* Copyright (c) 2023, 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 8320330
* @summary Test that RShiftINode optimizations are being performed as expected.
* @library /test/lib /
* @run driver compiler.c2.irTests.RShiftINodeIdealizationTests
*/
public class RShiftINodeIdealizationTests {
public static void main(String[] args) {
TestFramework.run();
}
@Run(test = { "test1", "test2", "test3", "test4" })
public void runMethod() {
int a = RunInfo.getRandom().nextInt();
int b = RunInfo.getRandom().nextInt();
int c = RunInfo.getRandom().nextInt();
int d = RunInfo.getRandom().nextInt();
int min = Integer.MIN_VALUE;
int max = Integer.MAX_VALUE;
assertResult(a, 0);
assertResult(a, b);
assertResult(b, a);
assertResult(c, d);
assertResult(d, c);
assertResult(min, max);
assertResult(max, min);
assertResult(min, min);
assertResult(max, max);
}
@DontCompile
public void assertResult(int x, int y) {
Asserts.assertEQ((x >> y) >= 0 ? 0 : 1, test1(x, y));
Asserts.assertEQ(((x & 127) >> y) >= 0 ? 0 : 1, test2(x, y));
Asserts.assertEQ(((-(x & 127) - 1) >> y) >= 0 ? 0 : 1, test3(x, y));
Asserts.assertEQ((x >> 30) > 4 ? 0 : 1, test4(x, y));
}
@Test
@IR(counts = { IRNode.RSHIFT, "1" })
public int test1(int x, int y) {
return (x >> y) >= 0 ? 0 : 1;
}
@Test
@IR(failOn = { IRNode.RSHIFT })
public int test2(int x, int y) {
return ((x & 127) >> y) >= 0 ? 0 : 1;
}
@Test
@IR(failOn = { IRNode.RSHIFT })
public int test3(int x, int y) {
return ((-(x & 127) - 1) >> y) >= 0 ? 0 : 1;
}
@Test
@IR(failOn = { IRNode.RSHIFT })
public int test4(int x, int y) {
return (x >> 30) > 4 ? 0 : 1;
}
}

92
test/hotspot/jtreg/compiler/c2/irTests/RShiftLNodeIdealizationTests.java Normal file
View File

@ -0,0 +1,92 @@
/*
* Copyright (c) 2023, 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 8320330
* @summary Test that RShiftLNode optimizations are being performed as expected.
* @library /test/lib /
* @run driver compiler.c2.irTests.RShiftLNodeIdealizationTests
*/
public class RShiftLNodeIdealizationTests {
public static void main(String[] args) {
TestFramework.run();
}
@Run(test = { "test1", "test2", "test3", "test4" })
public void runMethod() {
long a = RunInfo.getRandom().nextLong();
long b = RunInfo.getRandom().nextLong();
long c = RunInfo.getRandom().nextLong();
long d = RunInfo.getRandom().nextLong();
long min = Long.MIN_VALUE;
long max = Long.MAX_VALUE;
assertResult(a, 0);
assertResult(a, b);
assertResult(b, a);
assertResult(c, d);
assertResult(d, c);
assertResult(min, max);
assertResult(max, min);
assertResult(min, min);
assertResult(max, max);
}
@DontCompile
public void assertResult(long x, long y) {
Asserts.assertEQ((x >> y) >= 0 ? 0L : 1L, test1(x, y));
Asserts.assertEQ(((x & 127) >> y) >= 0 ? 0L : 1L, test2(x, y));
Asserts.assertEQ(((-(x & 127) - 1) >> y) >= 0 ? 0L : 1L, test3(x, y));
Asserts.assertEQ((x >> 62) > 4 ? 0L : 1L, test4(x, y));
}
@Test
@IR(counts = { IRNode.RSHIFT, "1" })
public long test1(long x, long y) {
return (x >> y) >= 0 ? 0 : 1;
}
@Test
@IR(failOn = { IRNode.RSHIFT })
public long test2(long x, long y) {
return ((x & 127) >> y) >= 0 ? 0L : 1L;
}
@Test
@IR(failOn = { IRNode.RSHIFT })
public long test3(long x, long y) {
return ((-(x & 127) - 1) >> y) >= 0 ? 0L : 1L;
}
@Test
@IR(failOn = { IRNode.RSHIFT })
public long test4(long x, long y) {
return (x >> 62) > 4 ? 0L : 1L;
}
}