66 lines
3 KiB
Markdown
66 lines
3 KiB
Markdown
# HW3: LLVMlite backend
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Quick Start:
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1. open the folder in VSCode
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2. start an OCaml sandbox terminal
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3. run `make test` from the command line
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4. open `bin/backend.ml`
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See the general toolchain and project instructions on the course web site. The
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course web pages have a link to the html version of the homework instructions.
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Using ``oatc``
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--------------
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oatc acts like the clang compiler. Given several .ll, .c, and .o
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files, it will compile the .ll files to .s files (using the cs131
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backend) and then combine the results with the .c and .o files to
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produce an executable named a.out. You can also compile the .ll files
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using clang instead of the cs131 backend, which can be useful for
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testing purposes.
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* To run the automated test harness do:
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./oatc --test
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* To compile ll files using the 131 backend:
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./oatc path/to/foo.ll
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- creates output/foo.s backend assembly code
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- creates output/foo.o assembled object file
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- creates a.out linked executable
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NOTE: by default the .s and .o files are created in a directory
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called output, and the filenames are chosen so that multiple runs of
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the compiler will not overwrite previous outputs. foo.ll will be
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compiled first to foo.s then foo\_1.s, foo\_2.s, etc.
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* To compile ll files using the clang backend:
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./oatc --clang path/to/foo.ll
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* Useful flags:
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| Flag | Description |
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| --print-ll | echoes the ll program to the terminal |
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| --print-x86 | echoes the resulting .s file to the terminal |
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| --interpret-ll | runs the ll file through the reference interpreter and outputs the results to the console |
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| --execute-x86 | runs the resulting a.out file natively (applies to either the 131 backend or clang-compiled code) |
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| -v | generates verbose output, showing which commands are used for linking, etc. |
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| -op ``<dirname>`` | change the output path [DEFAULT=output] |
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| -o | change the generated executable's name [DEFAULT=a.out] |
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| -S | stop after generating .s files |
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| -c | stop after generating .o files |
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| -h or --help | display the list of options |
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* Example uses:
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Run the test case llprograms/factrect.ll using the 131 backend:
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./oatc --execute-x86 llprograms/factrect.ll
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--------------------------------------------------------------- Executing: a.out
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* a.out returned 120
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