Contents

• PostgreSQL popcount function for data type bit(n).
  • usage
  • benchmarks
  • results
  • generate lookup table
  • check for POPCNT hardware support

PostgreSQL popcount function for data type bit(n).

Provides popcount, popcount32, popcount64, popcountAsm, popcountAsm64 and popcount256 functions to PostgreSQL.

usage

Requires pg_config installed.

sh make install make installcheck

benchmarks

Make sure the extension is installed CREATE EXTENSION popcount;.

```sh ./helper/generate_db_postgres.sh -a 512 ./benchmark/postgres.sh [-s popcount -t 10 -a 512 --units --color]

./helper/generate_db_mysql.sh -d

option | values | comment --- | --- | --- -s | popcount, popcount32, popcount64, popcountAsm, popcountAsm64, popcount256 | 8bit lookup table, 32bit hamming weight, 64bit hamming weight, 32 bit intrinsic function, 64 bit intrinsic function, unrolled assembly instruction. -t | integer | Number of trials. -a | integer | Bit alignment length. --units | - | Whether time units should be printed or not. --color | - | Colorize output.

results

generate lookup table

sh gcc -o ./helper/lookup_table_generator.o ./helper/lookup_table_generator.c ./helper/lookup_table_generator.o -n 256

check for POPCNT hardware support

sh gcc -o ./helper/popcnt_support.o ./helper/popcnt_support.c ./helper/popcnt_support.o