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/*
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
public class Main {
// TODO: make this work when b/26700769 is done.
//
// CHECK-START-X86_64: int Main.bits32(int) disassembly (after)
// CHECK-DAG: popcnt
//
// CHECK-START-X86_64: int Main.bits32(int) disassembly (after)
// CHECK-NOT: call
private static int bits32(int x) {
return Integer.bitCount(x);
}
// TODO: make this work when b/26700769 is done.
//
// CHECK-START-X86_64: int Main.bits64(long) disassembly (after)
// CHECK-DAG: popcnt
//
// CHECK-START-X86_64: int Main.bits64(long) disassembly (after)
// CHECK-NOT: call
private static int bits64(long x) {
return Long.bitCount(x);
}
public static void main(String args[]) {
expectEquals32(bits32(0x00000000), 0);
expectEquals32(bits32(0x00000001), 1);
expectEquals32(bits32(0x10000000), 1);
expectEquals32(bits32(0x10000001), 2);
expectEquals32(bits32(0x00000003), 2);
expectEquals32(bits32(0x70000000), 3);
expectEquals32(bits32(0x000F0000), 4);
expectEquals32(bits32(0x00001111), 4);
expectEquals32(bits32(0x11110000), 4);
expectEquals32(bits32(0x11111111), 8);
expectEquals32(bits32(0x12345678), 13);
expectEquals32(bits32(0x9ABCDEF0), 19);
expectEquals32(bits32(0xFFFFFFFF), 32);
for (int i = 0; i < 32; i++) {
expectEquals32(bits32(1 << i), 1);
}
expectEquals64(bits64(0x0000000000000000L), 0);
expectEquals64(bits64(0x0000000000000001L), 1);
expectEquals64(bits64(0x1000000000000000L), 1);
expectEquals64(bits64(0x1000000000000001L), 2);
expectEquals64(bits64(0x0000000000000003L), 2);
expectEquals64(bits64(0x7000000000000000L), 3);
expectEquals64(bits64(0x000F000000000000L), 4);
expectEquals64(bits64(0x0000000011111111L), 8);
expectEquals64(bits64(0x1111111100000000L), 8);
expectEquals64(bits64(0x1111111111111111L), 16);
expectEquals64(bits64(0x123456789ABCDEF1L), 33);
expectEquals64(bits64(0xFFFFFFFFFFFFFFFFL), 64);
for (int i = 0; i < 64; i++) {
expectEquals64(bits64(1L << i), 1);
}
System.out.println("passed");
}
private static void expectEquals32(int expected, int result) {
if (expected != result) {
throw new Error("Expected: " + expected + ", found: " + result);
}
}
private static void expectEquals64(long expected, long result) {
if (expected != result) {
throw new Error("Expected: " + expected + ", found: " + result);
}
}
}
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