45 lines
1.5 KiB
Python
Executable file
45 lines
1.5 KiB
Python
Executable file
#!/usr/bin/env python
|
|
|
|
# Import the llvm-py modules.
|
|
from llvm import *
|
|
from llvm.core import *
|
|
|
|
# Create an (empty) module.
|
|
my_module = Module.new('my_module')
|
|
|
|
# All the types involved here are "int"s. This type is represented
|
|
# by an object of the llvm.core.Type class:
|
|
ty_int = Type.int() # by default 32 bits
|
|
|
|
# We need to represent the class of functions that accept two integers
|
|
# and return an integer. This is represented by an object of the
|
|
# function type (llvm.core.FunctionType):
|
|
ty_func = Type.function(ty_int, [ty_int, ty_int])
|
|
|
|
# Now we need a function named 'sum' of this type. Functions are not
|
|
# free-standing (in llvm-py); it needs to be contained in a module.
|
|
f_sum = my_module.add_function(ty_func, "sum")
|
|
|
|
# Let's name the function arguments as 'a' and 'b'.
|
|
f_sum.args[0].name = "a"
|
|
f_sum.args[1].name = "b"
|
|
|
|
# Our function needs a "basic block" -- a set of instructions that
|
|
# end with a terminator (like return, branch etc.). By convention
|
|
# the first block is called "entry".
|
|
bb = f_sum.append_basic_block("entry")
|
|
|
|
# Let's add instructions into the block. For this, we need an
|
|
# instruction builder:
|
|
builder = Builder.new(bb)
|
|
|
|
# OK, now for the instructions themselves. We'll create an add
|
|
# instruction that returns the sum as a value, which we'll use
|
|
# a ret instruction to return.
|
|
tmp = builder.add(f_sum.args[0], f_sum.args[1], "tmp")
|
|
builder.ret(tmp)
|
|
|
|
# We've completed the definition now! Let's see the LLVM assembly
|
|
# language representation of what we've created:
|
|
print(my_module)
|
|
|