LLVM - Perl bindings to the Low Level Virtual Machine
use LLVM; # create a new LLVM context and a module named "synopsis" my $mod = LLVM::Module -> new("synopsis"); # create a new function type that takes 2 ints and returns one int my $intt = LLVM::Type -> int(32); my $funt = LLVM::Type -> func($intt, $intt, $intt); # add a new function to the module with the just-created type my $fun = $mod -> add_func("add", $funt); # set function's parameters names my $params = $fun -> func_params; $params -> [0] -> name("x"); $params -> [1] -> name("y"); # create a new instruction builder my $bld = LLVM::Builder -> new; # create a new entry block for the "add" function and position the # builder at its end my $blk = $fun -> func_append("entry"); $bld -> position_at_end($blk); # create an "add" intruction and use its return value as function return my $tmp = $bld -> add($params -> [0], $params -> [1], "tmp"); $bld -> ret($tmp); # dump the LLVM IR to stderr $mod -> dump;
The output should look like this:
; ModuleID = 'synopsis' define i32 @add(i32 %x, i32 %y) { entry: %tmp = add i32 %x, %y ret i32 %tmp }
Once the module is created, a number of optimizations can be applied:
# create a new LLVM::PassManager my $mgr = LLVM::PassManager -> new; # schedule a couple of passes $mgr -> add("FunctionInlining"); $mgr -> add("GlobalDCE"); # run the pass manager on the module $mgr -> run($mod);
And finally the module can be compiled in-memory and executed:
# create the arguments for the function call my $arg1 = LLVM::GenericValue -> int($intt, 5); my $arg2 = LLVM::GenericValue -> int($intt, 10); # create an execution engine for the module my $eng = LLVM::ExecutionEngine -> new($mod); # call the function "add" and print the result my $result = $eng -> run_func($fun, $arg1, $arg2); say $result -> to_int;
Or compiled to object code:
# get the first target available my $target = LLVM::Target -> targets -> [0]; # create a target machine my $tm = LLVM::TargetMachine -> create( $target, 'x86_64-linux-gnu', 'penryn', ['64bit'] ); # emit the object code to disk $tm -> emit($mod, 'synopsis.o', 1);
The Low-Level Virtual Machine (LLVM) is a collection of libraries and tools that make it easy to build compilers, optimizers, Just-In-Time code generators, and many other compiler-related programs. This module provides Perl bindings to the LLVM API.
Note: LLVM v3.1 is required to build this distribution.
Alessandro Ghedini <alexbio@cpan.org>
Copyright 2012 Alessandro Ghedini.
This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.
See http://dev.perl.org/licenses/ for more information.
To install LLVM, copy and paste the appropriate command in to your terminal.
cpanm
cpanm LLVM
CPAN shell
perl -MCPAN -e shell install LLVM
For more information on module installation, please visit the detailed CPAN module installation guide.