936546dcbc
Eliminate the separate 'len' variable from the loops, and also use the 4 byte instruction. This shaves off a few more cycles. Even though this routine that uses the special SSE 4.2 instructions is much faster than a generic routine, it's still a hot spot, so let's make it as fast as possible. Change the configure test to not test _mm_crc32_u64. That variant is only available in the 64-bit x86-64 architecture, not in 32-bit x86. Modify pg_comp_crc32c_sse42 so that it only uses _mm_crc32_u64 on x86-64. With these changes, the SSE accelerated CRC-32C implementation can also be used on 32-bit x86 systems. This also fixes the 32-bit MSVC build.
PostgreSQL Database Management System ===================================== This directory contains the source code distribution of the PostgreSQL database management system. PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings. PostgreSQL has many language interfaces, many of which are listed here: http://www.postgresql.org/download See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at http://www.postgresql.org/download/. For more information look at our web site located at http://www.postgresql.org/.