--- a/hotspot/src/cpu/aarch64/vm/c1_LIRGenerator_aarch64.cpp Tue Jun 20 17:00:07 2017 +0800
+++ b/hotspot/src/cpu/aarch64/vm/c1_LIRGenerator_aarch64.cpp Tue Jun 20 13:44:43 2017 +0000
@@ -598,12 +598,12 @@
} else {
assert (x->op() == Bytecodes::_imul, "expect imul");
if (right.is_constant()) {
- int c = right.get_jint_constant();
- if (! is_power_of_2(c) && ! is_power_of_2(c + 1) && ! is_power_of_2(c - 1)) {
+ jint c = right.get_jint_constant();
+ if (c > 0 && c < max_jint && (is_power_of_2(c) || is_power_of_2(c - 1) || is_power_of_2(c + 1))) {
+ right_arg->dont_load_item();
+ } else {
// Cannot use constant op.
- right.load_item();
- } else {
- right.dont_load_item();
+ right_arg->load_item();
}
} else {
right.load_item();
--- a/hotspot/src/cpu/arm/vm/c1_LIRGenerator_arm.cpp Tue Jun 20 17:00:07 2017 +0800
+++ b/hotspot/src/cpu/arm/vm/c1_LIRGenerator_arm.cpp Tue Jun 20 13:44:43 2017 +0000
@@ -923,8 +923,8 @@
} else {
left_arg->load_item();
if (x->op() == Bytecodes::_imul && right_arg->is_constant()) {
- int c = right_arg->get_jint_constant();
- if (c > 0 && (is_power_of_2(c) || is_power_of_2(c - 1) || is_power_of_2(c + 1))) {
+ jint c = right_arg->get_jint_constant();
+ if (c > 0 && c < max_jint && (is_power_of_2(c) || is_power_of_2(c - 1) || is_power_of_2(c + 1))) {
right_arg->dont_load_item();
} else {
right_arg->load_item();
--- a/hotspot/src/cpu/x86/vm/c1_LIRGenerator_x86.cpp Tue Jun 20 17:00:07 2017 +0800
+++ b/hotspot/src/cpu/x86/vm/c1_LIRGenerator_x86.cpp Tue Jun 20 13:44:43 2017 +0000
@@ -234,8 +234,8 @@
}
-bool LIRGenerator::strength_reduce_multiply(LIR_Opr left, int c, LIR_Opr result, LIR_Opr tmp) {
- if (tmp->is_valid()) {
+bool LIRGenerator::strength_reduce_multiply(LIR_Opr left, jint c, LIR_Opr result, LIR_Opr tmp) {
+ if (tmp->is_valid() && c > 0 && c < max_jint) {
if (is_power_of_2(c + 1)) {
__ move(left, tmp);
__ shift_left(left, log2_intptr(c + 1), left);
@@ -603,8 +603,8 @@
bool use_constant = false;
bool use_tmp = false;
if (right_arg->is_constant()) {
- int iconst = right_arg->get_jint_constant();
- if (iconst > 0) {
+ jint iconst = right_arg->get_jint_constant();
+ if (iconst > 0 && iconst < max_jint) {
if (is_power_of_2(iconst)) {
use_constant = true;
} else if (is_power_of_2(iconst - 1) || is_power_of_2(iconst + 1)) {
--- a/hotspot/src/share/vm/c1/c1_LIRGenerator.cpp Tue Jun 20 17:00:07 2017 +0800
+++ b/hotspot/src/share/vm/c1/c1_LIRGenerator.cpp Tue Jun 20 13:44:43 2017 +0000
@@ -545,11 +545,11 @@
case Bytecodes::_imul:
{
- bool did_strength_reduce = false;
+ bool did_strength_reduce = false;
if (right->is_constant()) {
- int c = right->as_jint();
- if (is_power_of_2(c)) {
+ jint c = right->as_jint();
+ if (c > 0 && is_power_of_2(c)) {
// do not need tmp here
__ shift_left(left_op, exact_log2(c), result_op);
did_strength_reduce = true;
--- a/hotspot/src/share/vm/c1/c1_LIRGenerator.hpp Tue Jun 20 17:00:07 2017 +0800
+++ b/hotspot/src/share/vm/c1/c1_LIRGenerator.hpp Tue Jun 20 13:44:43 2017 +0000
@@ -313,7 +313,7 @@
// is_strictfp is only needed for mul and div (and only generates different code on i486)
void arithmetic_op(Bytecodes::Code code, LIR_Opr result, LIR_Opr left, LIR_Opr right, bool is_strictfp, LIR_Opr tmp, CodeEmitInfo* info = NULL);
// machine dependent. returns true if it emitted code for the multiply
- bool strength_reduce_multiply(LIR_Opr left, int constant, LIR_Opr result, LIR_Opr tmp);
+ bool strength_reduce_multiply(LIR_Opr left, jint constant, LIR_Opr result, LIR_Opr tmp);
void store_stack_parameter (LIR_Opr opr, ByteSize offset_from_sp_in_bytes);
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/compiler/c1/MultiplyByMaxInt.java Tue Jun 20 13:44:43 2017 +0000
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2017, 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 8181872
+ *
+ * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions
+ * -XX:CompileThreshold=100 -XX:+TieredCompilation -XX:TieredStopAtLevel=1
+ * -XX:-BackgroundCompilation -XX:CompileCommand=dontinline,compiler.c1.MultiplyByMaxInt::test
+ * compiler.c1.MultiplyByMaxInt
+ * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:-BackgroundCompilation
+ * -XX:CompileThreshold=100 -XX:+TieredCompilation -XX:TieredStopAtLevel=3
+ * -XX:CompileCommand=dontinline,compiler.c1.MultiplyByMaxInt::test
+ * compiler.c1.MultiplyByMaxInt
+ */
+package compiler.c1;
+
+public class MultiplyByMaxInt {
+ static int test(int x) {
+ int loops = (x >>> 4) & 7;
+ while (loops-- > 0) {
+ x = (x * 2147483647) % 16807;
+ }
+ return x;
+ }
+
+ public static void main(String[] args) {
+ for (int i = 0; i < 20000; i++) {
+ test(i);
+ }
+ }
+}