/ 
LLVM-0.03
River stage zero No dependents
/ LLVM

NAME

LLVM - Perl bindings to the Low Level Virtual Machine

VERSION

version 0.03

SYNOPSIS

use LLVM;

# create a new LLVM context and a module named "synopsis"
my $ctx = LLVM::Context -> new;
my $mod = LLVM::Module -> new($ctx, "synopsis");

# create a new function type that takes 2 ints and returns one int
my $intt = LLVM::Type -> int($ctx, 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] -> set_name("x");
$params -> [1] -> set_name("y");

# create a new entry block for the "add" function and its builder
my $blk = $fun -> func_append($ctx, "entry");
my $bld = LLVM::Builder -> new($ctx, $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 -> function_inlining;
$mgr -> global_dce;

# 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;

DESCRIPTION

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 that this module is currently built and tested against LLVM v3.1, but chances are that it builds against older versions too.

AUTHOR

Alessandro Ghedini <alexbio@cpan.org>

LICENSE AND COPYRIGHT

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.