8299179: ArrayFill with store on backedge needs to reduce length by 1

Reviewed-by: thartmann, kvn
This commit is contained in:
Emanuel Peter 2023-01-12 07:23:19 +00:00
parent af8d3fb21a
commit d716ec5d30
3 changed files with 429 additions and 0 deletions
src/hotspot/share/opto
test/hotspot/jtreg/compiler/loopopts

@ -4381,6 +4381,19 @@ bool PhaseIdealLoop::intrinsify_fill(IdealLoopTree* lpt) {
Node* len = new SubINode(head->limit(), head->init_trip());
_igvn.register_new_node_with_optimizer(len);
// If the store is on the backedge, it is not executed in the last
// iteration, and we must subtract 1 from the len.
Node* backedge = head->loopexit()->proj_out(1);
if (store->in(0) == backedge) {
len = new SubINode(len, _igvn.intcon(1));
_igvn.register_new_node_with_optimizer(len);
#ifndef PRODUCT
if (TraceOptimizeFill) {
tty->print_cr("ArrayFill store on backedge, subtract 1 from len.");
}
#endif
}
BasicType t = store->as_Mem()->memory_type();
bool aligned = false;
if (offset != NULL && head->init_trip()->is_Con()) {
@ -4483,5 +4496,12 @@ bool PhaseIdealLoop::intrinsify_fill(IdealLoopTree* lpt) {
_igvn.replace_node(n, C->top());
}
#ifndef PRODUCT
if (TraceOptimizeFill) {
tty->print("ArrayFill call ");
call->dump();
}
#endif
return true;
}

@ -0,0 +1,178 @@
/*
* 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.
*
*/
super public class TestBackedgeLoadArrayFill
{
public Method "<init>":"()V"
stack 2 locals 1
{
aload_0;
invokespecial Method java/lang/Object."<init>":"()V";
return;
}
static Method test_101:"()V"
stack 20 locals 20
{
// test_002 in jasm: using try-catch
ldc 6;
istore_0; // i = 6
ldc 25;
newarray int;
astore_1; // arr = new int[25]
HEAD:
aload_1;
iload_0;
iconst_1;
iastore; // arr[i] = 1
// second block - the only one -> head block can be copied: one before, one on backedge
try t0;
aload_1;
iload_0;
aload_1;
iload_0;
iaload;
iastore; // arr[i] = arr[i]
goto FINALLY;
endtry t0;
catch t0 java/lang/Exception;
pop; // exception
FINALLY:
iinc 0, 1; // i++
iload_0;
ldc 21;
if_icmplt HEAD; // if i < 21
// write array
aload_1;
putstatic Field TestBackedgeLoadArrayFillMain.intA:"[I";
return;
}
static Method test_102:"()V"
stack 20 locals 20
{
// test_002 in jasm: without try-catch
ldc 5;
istore_0; // i = 5
ldc 25;
newarray int;
astore_1; // arr = new int[25]
HEAD:
aload_1;
iload_0;
iconst_1;
iastore; // arr[i] = 1
goto SECOND;
// second block - the only one -> head block can be copied: one before, one on backedge
// must have some material before inc, else it is partial peeled away
// And if we set -XX:-PartialPeelLoop, then the counted loop is never detected
SECOND:
aload_1;
iload_0;
aload_1;
iload_0;
iaload;
iastore; // arr[i] = arr[i]
iinc 0, 1; // i++
iload_0;
ldc 21;
if_icmplt HEAD; // if i < 21
// write array
aload_1;
putstatic Field TestBackedgeLoadArrayFillMain.intA:"[I";
return;
}
static Method test_103:"()V"
stack 20 locals 20
{
// test_002 in jasm: without try-catch, and second array
ldc 7;
istore_0; // i = 7
ldc 25;
newarray int;
astore_1; // arr = new int[25]
ldc 25;
newarray int;
astore_2; // arr2 = new int[25]
HEAD:
aload_1;
iload_0;
iconst_1;
iastore; // arr[i] = 1
goto SECOND;
// second block - the only one -> head block can be copied: one before, one on backedge
SECOND:
// we can also do the identity read-write on another array - it just has to eventually disappear
aload_2;
iload_0;
aload_2;
iload_0;
iaload;
iastore; // arr2[i] = arr2[i]
iinc 0, 1; // i++
iload_0;
ldc 21;
if_icmplt HEAD; // if i < 21
// write array
aload_1;
putstatic Field TestBackedgeLoadArrayFillMain.intA:"[I";
return;
}
static Method test_104:"()V"
stack 20 locals 20
{
ldc 9;
istore_0; // i = 9
ldc 25;
newarray int;
astore_1; // arr = new int[25]
HEAD:
aload_1;
iload_0;
iconst_1;
iastore; // arr[i] = 1
goto SECOND;
// second block - the only one -> head block can be copied: one before, one on backedge
SECOND:
// CFG leads to partial peel -> load moved into loop body, then intrinsified
iload_0;
ldc 2;
irem;
ifeq SKIP;
SKIP:
iinc 0, 1; // i++
iload_0;
ldc 21;
if_icmplt HEAD; // if i < 21
// write array
aload_1;
putstatic Field TestBackedgeLoadArrayFillMain.intA:"[I";
return;
}
}

@ -0,0 +1,231 @@
/*
* 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.
*
*/
/*
* @test
* @bug 8299179
* @summary ArrayFill: if store is on backedge, last iteration is not to be executed.
* @library /test/lib
* @compile TestBackedgeLoadArrayFill.jasm
* @run main/othervm
* -XX:CompileCommand=compileonly,TestBackedgeLoadArrayFill*::test*
* -XX:-TieredCompilation -Xcomp -XX:+OptimizeFill
* TestBackedgeLoadArrayFillMain
* @run main/othervm
* -XX:CompileCommand=compileonly,TestBackedgeLoadArrayFill*::test*
* -XX:-TieredCompilation -Xcomp -XX:+OptimizeFill
* -XX:LoopUnrollLimit=1
* TestBackedgeLoadArrayFillMain
*/
import jdk.test.lib.Asserts;
public class TestBackedgeLoadArrayFillMain {
static long[] longA;
static int[] intA;
static short[] shortA;
static byte[] byteA;
static class Data {
long longValue;
int intValue;
short shortValue;
byte byteValue;
Data(int value) {
longValue = (long) value;
intValue = (int) value;
shortValue = (short) value;
longValue = (byte) value;
}
}
public static long longSum() {
long s = 0;
for (long v : longA) { s += v; }
return s;
}
public static int intSum() {
int s = 0;
for (int v : intA) { s += v; }
return s;
}
public static short shortSum() {
short s = 0;
for (short v : shortA) { s += v; }
return s;
}
public static byte byteSum() {
byte s = 0;
for (byte v : byteA) { s += v; }
return s;
}
static void test_001() {
// long seems not yet supported
int i = 6;
long arr[] = new long[22];
do {
arr[i] = 1;
try {
arr[i] = arr[i];
} catch (Exception e) {
}
} while (++i < 20);
longA = arr;
}
static void test_002() {
// jint_fill
int i = 6;
int arr[] = new int[22];
do {
arr[i] = 1;
try {
arr[i] = arr[i];
} catch (Exception e) {
}
} while (++i < 20);
intA = arr;
}
static void test_003() {
// jshort_fill
int i = 6;
short arr[] = new short[22];
do {
// first block of loop: copied before loop, and onto backedge -> store on backedge
arr[i] = 1;
// second block of loop
try {
arr[i] = arr[i];
} catch (Exception e) {
}
} while (++i < 20);
shortA = arr;
}
static void test_004() {
// jbyte_fill
int i = 6;
byte arr[] = new byte[22];
do {
arr[i] = 1;
try {
arr[i] = arr[i];
} catch (Exception e) {
}
} while (++i < 20);
byteA = arr;
}
static void test_005() {
// Note: currently unrolled, not intrinsified (unless -XX:LoopUnrollLimit=1)
int arr[] = new int[22];
for (int i = 6; i < 20; i++) {
arr[i] = 1;
}
intA = arr;
}
static void test_006() {
// Note: currently unrolled, not intrinsified (unless -XX:LoopUnrollLimit=1)
// Load in normal body, because not moved to backedge during parsing.
int i = 6;
int arr[] = new int[22];
do {
arr[i] = 1;
} while (++i < 20);
intA = arr;
}
static void test_007() {
int i = 6;
int arr[] = new int[22];
do {
// still not on backedge [7,20) partial peel
arr[i] = 1;
try { int x = arr[i]; } catch (Exception e) {}
} while (++i < 20);
intA = arr;
}
static void test_008(Data data) {
// Because of conditional in loop, at first not intrinsified, and also not unrolled.
// After unswitching both loops are intrinsified.
// I stole this idea from TestOptimizeFillWithStripMinedLoop.java
int i = 6;
int arr[] = new int[22];
do {
arr[i] = (data == null) ? 1 : data.intValue;
} while (++i < 20);
intA = arr;
}
static void test_009() {
// Cast to int leads to "missing use of index", not intrinsified
int arr[] = new int[22];
for (long i = 6; i < 20; i++) {
arr[(int)i] = 1;
}
intA = arr;
}
public static void main(String[] strArr) {
test_001();
Asserts.assertEQ(longSum(), (long)14);
test_002();
Asserts.assertEQ(intSum(), 14);
test_003();
Asserts.assertEQ(shortSum(), (short)14);
test_004();
Asserts.assertEQ(byteSum(), (byte)14);
test_005();
Asserts.assertEQ(intSum(), 14);
test_006();
Asserts.assertEQ(intSum(), 14);
test_007();
Asserts.assertEQ(intSum(), 14);
test_008(new Data(1));
Asserts.assertEQ(intSum(), 14);
test_008(null);
Asserts.assertEQ(intSum(), 14);
test_009();
Asserts.assertEQ(intSum(), 14);
TestBackedgeLoadArrayFill t = new TestBackedgeLoadArrayFill();
t.test_101();
Asserts.assertEQ(intSum(), 15);
t.test_102();
Asserts.assertEQ(intSum(), 16);
t.test_103();
Asserts.assertEQ(intSum(), 14);
t.test_104();
Asserts.assertEQ(intSum(), 12);
}
}