1 /*
2  * Copyright (c) 2017-2019, NVIDIA CORPORATION.  All rights reserved.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  *
16  */
17 
18 #include <stdint.h>
19 
20 int64_t
__mth_i_kpopcnt(uint64_t u64)21 __mth_i_kpopcnt(uint64_t u64)
22 {
23   uint64_t r64;
24 
25 #if     defined(TARGET_X8664)
26   asm("popcnt %1, %0"
27      : "=r"(r64)
28      : "r"(u64)
29      :
30      );
31 #elif   defined(TARGET_LINUX_POWER)
32     asm("popcntd    %0, %1"
33        : "=r"(r64)
34        : "r"(u64)
35        :
36        );
37 #else
38   static const uint64_t u5s = 0x5555555555555555ul;
39   static const uint64_t u3s = 0x3333333333333333ul;
40   static const uint64_t u7s = 0x0707070707070707ul;
41   static const uint64_t u1s = 0x0101010101010101ul;
42   r64 = u64;
43   r64 = (r64 & u5s) + (r64 >> 1 & u5s);
44   r64 = (r64 & u3s) + (r64 >> 2 & u3s);
45   r64 = (r64 & u7s) + (r64 >> 4 & u7s);
46   r64 *= u1s;
47   r64 >>= 56;
48 #endif
49 
50   return r64;
51 }
52