regexp

Regular Expression Matching example hardware description

This is an example in which some ColumnReaders are used to read a column with UTF8 strings. The config string for the columns is therefore "listprim(8)", to generate an interface to a non-nullable list of non-nullable 8-bit wide elements.

The design instantiates N of these ColumnReaders, attached to N regular expression matching units, that can all work in parallel.

N depends on the platform, how much room there is in the FPGA, etc. Currently, for AWS EC2 F1 instances N=16 and for CAPI SNAP on a ADKU3 N=8.

The ColumnReaders are attached to our internal bus arbiter/interconnect, but we inserted an axi_read_converter to convert the bsize (Burst Size) signal properly to match the AWS Shell requirement of setting this to 2^6=64 bytes fixed burst beat size. This is because the ColumnReaders bus data width is 32-bits. axi_read_converter also converts our internal bus burst lengths to AXI specification. Furthermore, it includes a read response FIFO as we don't want to lock up the arbiter dumping bursts into the ColumnReaders, which are less wide.

Design files description

Hardware implementation:

File	Description
hardware/animals/*.vhd	The regular expression matchers generated using VHDRE. They all match to some names of pet animals.
hardware/arrow_regexp.vhd	The top-level for this platform-independent design.
hardware/arrow_regexp_unit.vhd	One regular expression matching unit which is instantiated N times to work in parallel.
hardware/arrow_regexp_pkg.vhd	The package for this example containing some constants and definitions.

Software implementation:

File	Description
software/src/regexp.cc	The main file for this example
software/src/regex-usercore.cc	The implementation of some convenience function of this specific application
software/src/regex-usercore.h	Header for previous item

Build

1. First build and install, on the host machine:

• The platform agnostic runtime library.
• The platform-specific run-time library.

2. Build the example on the host machine.

Proceed to build this application:

$ cd examples/regexp
$ mkdir build
$ cd build
$ cmake ..
$ make

3. Run the example:

./regexp

• Note: you probably need sudo rights for most platforms:

Optional parameters:

./regexp <no. strings> <no. repeats> <experiment mask> <num. threads>