.. index:: single: FAQ; keep intermediate .. _faq-keep-intermediate: How to keep HLS intermediate files generated by Mercurium? ========================================================== Mercurium generates an intermediate C++ HLS source file for each FPGA task defined in the source code. Those files are used by AIT to generate the FPGA bitstream, and removed after the invocation. To keep the Mercurium intermediate files, there is the ``-k`` option. It will keep the C/C++ intermediate files for the native compiler and the C++ HLS files for AIT. Usage example: .. code:: bash fpgacc --ompss --bitstream-generation -k src/dotproduct.c -o dotproduct \ --Wf,--board=zedboard .. note:: HLS source files are not generated if ``--bitstream-generation`` option is not used in Mercurium call **Edit the HLS intermediate files and call AIT** It is not recommended, but under some circumstances one would need to edit the HLS intermediate files before the AIT call. The following steps shows how to do so. 1. We call Mercurium with the desired options and two extra flags: - ``-k`` which keeps the intermediate files generated by the compiler. - ``--verbose`` which enables the verbose mode of the compiler. This is needed to gather the AIT command call that Mercurium executes. We could add an unsupported argument in the AIT flags to make it abort, as we do not want the bitstream before the modifications. For example, we could add the ``--abort`` flag to ``--Wf`` option of Mercurium. Example of Mercurium call and generated output: .. code:: bash [user@machine] $ fpgacc --ompss -k --verbose --bitstream-generation --Wf,-b=zcu102,--hwruntime=som,--abort foo.c -o foo Loading compiler phases for profile 'fpgacc' Compiler phases for profile 'fpgacc' loaded in 0.02 seconds Compiling file 'foo.c' gcc -E -D_OPENMP=200805 -D_OMPSS=1 -I/home/user/opt/ompss/git/nanox/include/nanox -include nanos.h -include nanos_omp.h -include nanos-fpga.h -std=gnu99 -D_MCC -D_MERCURIUM -o /tmp/fpgacc_zHMisA foo.c File 'foo.c' preprocessed in 0.01 seconds Parsing file 'foo.c' ('/tmp/fpgacc_zHMisA') File 'foo.c' ('/tmp/fpgacc_zHMisA') parsed in 0.02 seconds Nanos++ prerun Early compiler phases pipeline executed in 0.00 seconds File 'foo.c' ('/tmp/fpgacc_zHMisA') semantically analyzed in 0.01 seconds Checking parse tree consistency Parse tree consistency verified in 0.00 seconds Freeing parse tree Parse tree freed in 0.00 seconds Checking integrity of nodecl tree Nodecl integrity verified in 0.00 seconds foo.c:1:13: info: unless 'no_copy_deps' is specified, the default in OmpSs is now 'copy_deps' foo.c:1:13: info: this diagnostic is only shown for the first task found foo.c:2:13: info: adding task function 'foo' for device 'fpga' Nanos++ phase foo.c:10:3: info: call to task function 'foo' foo.c:2:13: info: task function declared here FPGA bitstream generation phase analysis - ON Compiler phases pipeline executed in 0.01 seconds Prettyprinted into file 'fpgacc_foo.c' in 0.00 seconds Performing native compilation of 'fpgacc_foo.c' into 'foo.o' gcc -std=gnu99 -c -o foo.o fpgacc_foo.c File 'foo.c' ('fpgacc_foo.c') natively compiled in 0.02 seconds objdump -w -h foo.o 1> /tmp/fpgacc_d9sKiY gcc -o foo -std=gnu99 foo.o -Xlinker --enable-new-dtags -L/home/user/opt/ompss/git/nanox/lib/performance -Xlinker -rpath -Xlinker /home/user/opt/ompss/git/nanox/lib/performance -Xlinker --no-as-needed -lnanox-ompss -lnanox-c -lnanox -lpthread -lrt -lnanox-fpga-api Link performed in 0.04 seconds ait -b=zcu102 --hwruntime=som --abort --wrapper_version=7 -n=foo usage: ait -b BOARD -n NAME ait error: unrecognized arguments: --abort. Try 'ait -h' for more information. Link fpga failed Removing temporary filename '/tmp/fpgacc_d9sKiY' Removing temporary filename 'foo.o' Removing temporary filename '/tmp/fpgacc_zHMisA' 2. Now the intermediate files are available and we could edit them as desired. In the example, ``7288177970:1:foo_hls_automatic_mcxx.cpp`` is available: .. code:: bash [user@machine] $ ls -l total 44 -rw-r--r-- 1 user user 3735 Jun 5 10:27 7288177970:1:foo_hls_automatic_mcxx.cpp -rwxr-xr-x 1 user user 17568 Jun 5 10:27 foo -rw-r--r-- 1 user user 235 Jun 4 15:17 foo.c -rw-r--r-- 1 user user 13460 Jun 5 10:27 fpgacc_foo.c 3. After modifying the HLS intermediate files, the AIT call that Mercurium usually performs has to be executed. In the verbose output of the first step, there is one line with the invoked call. This call has to be repeated, removing the extra options added to make AIT abort (if any). In the example, the ``--abort`` option has to be removed and the AIT command to invoke will be: .. code:: bash [user@machine] $ ait -b=zcu102 --hwruntime=som --wrapper_version=7 -n=foo Using xilinx backend Checking vendor support for selected board ...