Exemple #1
0
class GenerateLLVM(object):

    def __init__(self, name='module'):
        # Perform the basic LLVM initialization.  You need the following parts:
        #
        #    1.  A top-level Module object
        #    2.  A Function instance in which to insert code
        #    3.  A Builder instance to generate instructions
        #
        # Note: For project 5, we don't have any user-defined
        # functions so we're just going to emit all LLVM code into a top
        # level function void main() { ... }.   This will get changed later.

        self.module = Module(name)
        # self.function = Function(self.module,
        #                         FunctionType(void_type, []),
        #                         name='main')

        # self.block = self.function.append_basic_block('entry')
        self.block = None
        # self.builder = IRBuilder(self.block)
        self.builder = None

        # Dictionary that holds all of the global variable/function
        # declarations.
        # Any declaration in the Gone source code is going to get an entry here
        # self.vars = {}
        self.globals = {}
        self.locals = {}

        # Dictionary that holds all of the temporary variables created in
        # the intermediate code.   For example, if you had an expression
        # like this:
        #
        #      a = b + c*d
        #
        # The corresponding intermediate code might look like this:
        #
        #      ('load_int', 'b', 'int_1')
        #      ('load_int', 'c', 'int_2')
        #      ('load_int', 'd', 'int_3')
        #      ('mul_int', 'int_2','int_3','int_4')
        #      ('add_int', 'int_1','int_4','int_5')
        #      ('store_int', 'int_5', 'a')
        #
        # The self.temp dictionary below is used to map names such as 'int_1',
        # 'int_2' to their corresponding LLVM values.  Essentially, every time
        # you make anything in LLVM, it gets stored here.
        self.temps = {}

        # Initialize the runtime library functions (see below)
        self.declare_runtime_library()

        self.last_branch = None

    def start_function(self, name, rettypename, parmtypenames):
        rettype = typemap[rettypename]
        parmtypes = [typemap[pname] for pname in parmtypenames]
        # Type.function(rettype, parmtypes, False)
        func_type = FunctionType(rettype, parmtypes)

        # Create the function for which we're generating code
        # Function.new(self.module, func_type, name)
        self.function = Function(self.module, func_type, name=name)

        # Make the builder and entry block
        self.block = self.function.append_basic_block("entry")
        self.builder = IRBuilder(self.block)

        # Make the exit block
        self.exit_block = self.function.append_basic_block("exit")

        # Clear the local vars and temps
        self.locals = {}
        self.temps = {}

        # Make the return variable
        if rettype is not void_type:
            self.locals['return'] = self.builder.alloca(rettype, name="return")

        # Put an entry in the globals
        self.globals[name] = self.function

    def new_basic_block(self, name=''):
        self.builder = IRBuilder(self.block.instructions)
        return self.function.append_basic_block(name)

    def declare_runtime_library(self):
        # Certain functions such as I/O and string handling are often easier
        # to implement in an external C library.  This method should make
        # the LLVM declarations for any runtime functions to be used
        # during code generation.    Please note that runtime function
        # functions are implemented in C in a separate file gonert.c

        self.runtime = {}

        # Declare printing functions
        self.runtime['_print_int'] = Function(self.module,
                                              FunctionType(
                                                  void_type, [int_type]),
                                              name="_print_int")

        self.runtime['_print_float'] = Function(self.module,
                                                FunctionType(
                                                    void_type, [float_type]),
                                                name="_print_float")

        self.runtime['_print_bool'] = Function(self.module,
                                               FunctionType(
                                                   void_type, [int_type]),
                                               name="_print_bool")

    def generate_code(self, ircode):
        # Given a sequence of SSA intermediate code tuples, generate LLVM
        # instructions using the current builder (self.builder).  Each
        # opcode tuple (opcode, args) is dispatched to a method of the
        # form self.emit_opcode(args)

        for opcode, *args in ircode:
            if hasattr(self, 'emit_' + opcode):
                getattr(self, 'emit_' + opcode)(*args)
            else:
                print('Warning: No emit_' + opcode + '() method')

        # Add a return statement.  Note, at this point, we don't really have
        # user-defined functions so this is a bit of hack--it may be removed
        # later.
        # self.builder.ret_void()

    def terminate(self):
        # Add a return statement. This connects the last block to the exit
        # block.
        # The return statement is then emitted
        if self.last_branch != self.block:
            self.builder.branch(self.exit_block)
        self.builder.position_at_end(self.exit_block)

        if 'return' in self.locals:
            self.builder.ret(self.builder.load(self.locals['return']))
        else:
            self.builder.ret_void()

    def add_block(self, name):
        # Add a new block to the existing function
        return self.function.append_basic_block(name)

    def set_block(self, block):
        # Sets the current block for adding more code
        self.block = block
        self.builder.position_at_end(block)

    def cbranch(self, testvar, true_block, false_block):
        self.builder.cbranch(self.temps[testvar], true_block, false_block)

    def branch(self, next_block):
        if self.last_branch != self.block:
            self.builder.branch(next_block)
        self.last_branch = self.block
    # ----------------------------------------------------------------------
    # Opcode implementation.   You must implement the opcodes.  A few
    # sample opcodes have been given to get you started.
    # ----------------------------------------------------------------------

    # Creation of literal values.  Simply define as LLVM constants.
    def emit_literal_int(self, value, target):
        self.temps[target] = Constant(int_type, value)

    def emit_literal_float(self, value, target):
        self.temps[target] = Constant(float_type, value)

    def emit_literal_bool(self, value, target):
        self.temps[target] = Constant(bool_type, value)

    # def emit_literal_string(self, value, target):
    #     self.temps[target] = Constant(string_type, value)

    # Allocation of variables.  Declare as global variables and set to
    # a sensible initial value.
    def emit_alloc_int(self, name):
        var = self.builder.alloca(int_type, name=name)
        var.initializer = Constant(int_type, 0)
        self.locals[name] = var

    def emit_alloc_float(self, name):
        var = self.builder.alloca(float_type, name=name)
        var.initializer = Constant(float_type, 0)
        self.locals[name] = var

    def emit_alloc_bool(self, name):
        var = self.builder.alloca(bool_type, name=name)
        var.initializer = Constant(bool_type, 0)
        self.locals[name] = var

    def emit_global_int(self, name):
        var = GlobalVariable(self.module, int_type, name=name)
        var.initializer = Constant(int_type, 0)
        self.globals[name] = var

    def emit_global_float(self, name):
        var = GlobalVariable(self.module, float_type, name=name)
        var.initializer = Constant(float_type, 0)
        self.globals[name] = var

    def emit_global_bool(self, name):
        var = GlobalVariable(self.module, bool_type, name=name)
        var.initializer = Constant(bool_type, 0)
        self.globals[name] = var

    # def emit_alloc_string(self, name):
    #     var = GlobalVariable(self.module, string_type, name=name)
    #     var.initializer = Constant(string_type, "")
    #     self.vars[name] = var

    # Load/store instructions for variables.  Load needs to pull a
    # value from a global variable and store in a temporary. Store
    # goes in the opposite direction.
    def lookup_var(self, name):
        if name in self.locals:
            return self.locals[name]
        else:
            return self.globals[name]

    def emit_load_int(self, name, target):
        # print('LOADINT %s, %s' % (name, target))
        # print('GLOBALS %s' % self.globals)
        # print('LOCALS %s' % self.locals)
        self.temps[target] = self.builder.load(self.lookup_var(name), target)

    def emit_load_float(self, name, target):
        self.temps[target] = self.builder.load(self.lookup_var(name), target)

    def emit_load_bool(self, name, target):
        self.temps[target] = self.builder.load(self.lookup_var(name), target)

    def emit_store_int(self, source, target):
        self.builder.store(self.temps[source], self.lookup_var(target))

    def emit_store_float(self, source, target):
        self.builder.store(self.temps[source], self.lookup_var(target))

    def emit_store_bool(self, source, target):
        self.builder.store(self.temps[source], self.lookup_var(target))

    # Binary + operator
    def emit_add_int(self, left, right, target):
        self.temps[target] = self.builder.add(
            self.temps[left], self.temps[right], target)

    def emit_add_float(self, left, right, target):
        self.temps[target] = self.builder.fadd(
            self.temps[left], self.temps[right], target)

    # Binary - operator
    def emit_sub_int(self, left, right, target):
        self.temps[target] = self.builder.sub(
            self.temps[left], self.temps[right], target)

    def emit_sub_float(self, left, right, target):
        self.temps[target] = self.builder.fsub(
            self.temps[left], self.temps[right], target)

    # Binary * operator
    def emit_mul_int(self, left, right, target):
        self.temps[target] = self.builder.mul(
            self.temps[left], self.temps[right], target)

    def emit_mul_float(self, left, right, target):
        self.temps[target] = self.builder.fmul(
            self.temps[left], self.temps[right], target)

    # Binary / operator
    def emit_div_int(self, left, right, target):
        self.temps[target] = self.builder.sdiv(
            self.temps[left], self.temps[right], target)

    def emit_div_float(self, left, right, target):
        self.temps[target] = self.builder.fdiv(
            self.temps[left], self.temps[right], target)

    # Unary + operator
    def emit_uadd_int(self, source, target):
        self.temps[target] = self.builder.add(
            Constant(int_type, 0),
            self.temps[source],
            target)

    def emit_uadd_float(self, source, target):
        self.temps[target] = self.builder.fadd(
            Constant(float_type, 0.0),
            self.temps[source],
            target)

    # Unary - operator
    def emit_usub_int(self, source, target):
        self.temps[target] = self.builder.sub(
            Constant(int_type, 0),
            self.temps[source],
            target)

    def emit_usub_float(self, source, target):
        self.temps[target] = self.builder.fsub(
            Constant(float_type, 0.0),
            self.temps[source],
            target)

    # Binary < operator
    def emit_lt_int(self, left, right, target):
        self.temps[target] = self.builder.icmp_signed(
            '<', self.temps[left], self.temps[right], target)

    def emit_lt_float(self, left, right, target):
        self.temps[target] = self.builder.fcmp_ordered(
            '<', self.temps[left], self.temps[right], target)

    # Binary <= operator
    def emit_le_int(self, left, right, target):
        self.temps[target] = self.builder.icmp_signed(
            '<=', self.temps[left], self.temps[right], target)

    def emit_le_float(self, left, right, target):
        self.temps[target] = self.builder.fcmp_ordered(
            '<=', self.temps[left], self.temps[right], target)

    # Binary > operator
    def emit_gt_int(self, left, right, target):
        self.temps[target] = self.builder.icmp_signed(
            '>', self.temps[left], self.temps[right], target)

    def emit_gt_float(self, left, right, target):
        self.temps[target] = self.builder.fcmp_ordered(
            '>', self.temps[left], self.temps[right], target)

    # Binary >= operator
    def emit_ge_int(self, left, right, target):
        self.temps[target] = self.builder.icmp_signed(
            '>=', self.temps[left], self.temps[right], target)

    def emit_ge_float(self, left, right, target):
        self.temps[target] = self.builder.fcmp_ordered(
            '>=', self.temps[left], self.temps[right], target)

    # Binary == operator
    def emit_eq_int(self, left, right, target):
        self.temps[target] = self.builder.icmp_signed(
            '==', self.temps[left], self.temps[right], target)

    def emit_eq_bool(self, left, right, target):
        self.temps[target] = self.builder.icmp_signed(
            '==', self.temps[left], self.temps[right], target)

    def emit_eq_float(self, left, right, target):
        self.temps[target] = self.builder.fcmp_ordered(
            '==', self.temps[left], self.temps[right], target)

    # Binary != operator
    def emit_ne_int(self, left, right, target):
        self.temps[target] = self.builder.icmp_signed(
            '!=', self.temps[left], self.temps[right], target)

    def emit_ne_bool(self, left, right, target):
        self.temps[target] = self.builder.icmp_signed(
            '!=', self.temps[left], self.temps[right], target)

    def emit_ne_float(self, left, right, target):
        self.temps[target] = self.builder.fcmp_ordered(
            '!=', self.temps[left], self.temps[right], target)

    # Binary && operator
    def emit_and_bool(self, left, right, target):
        self.temps[target] = self.builder.and_(
            self.temps[left], self.temps[right], target)

    # Binary || operator
    def emit_or_bool(self, left, right, target):
        self.temps[target] = self.builder.or_(
            self.temps[left], self.temps[right], target)

    # Unary ! operator
    def emit_not_bool(self, source, target):
        self.temps[target] = self.builder.icmp_signed(
            '==', self.temps[source], Constant(bool_type, 0), target)
    # Print statements

    def emit_print_int(self, source):
        self.builder.call(self.runtime['_print_int'], [self.temps[source]])

    def emit_print_float(self, source):
        self.builder.call(self.runtime['_print_float'], [self.temps[source]])

    def emit_print_bool(self, source):
        self.builder.call(self.runtime['_print_bool'], [
                          self.builder.zext(self.temps[source], int_type)])

    # Extern function declaration.
    def emit_extern_func(self, name, rettypename, *parmtypenames):
        rettype = typemap[rettypename]
        parmtypes = [typemap[pname] for pname in parmtypenames]
        func_type = FunctionType(rettype, parmtypes)
        self.globals[name] = Function(self.module, func_type, name=name)

    # Call an external function.
    def emit_call_func(self, funcname, *args):
        target = args[-1]
        func = self.globals[funcname]
        argvals = [self.temps[name] for name in args[:-1]]
        self.temps[target] = self.builder.call(func, argvals)

    # Function parameter declarations.  Must create as local variables
    def emit_parm_int(self, name, num):
        var = self.builder.alloca(int_type, name=name)
        self.builder.store(self.function.args[num], var)
        self.locals[name] = var

    def emit_parm_float(self, name, num):
        var = self.builder.alloca(float_type, name=name)
        self.builder.store(self.function.args[num], var)
        self.locals[name] = var

    def emit_parm_bool(self, name, num):
        var = self.builder.alloca(bool_type, name=name)
        self.builder.store(self.function.args[num], var)
        self.locals[name] = var

    # Return statements
    def emit_return_int(self, source):
        self.builder.store(self.temps[source], self.locals['return'])
        self.branch(self.exit_block)

    def emit_return_float(self, source):
        self.builder.store(self.temps[source], self.locals['return'])
        self.branch(self.exit_block)

    def emit_return_bool(self, source):
        self.builder.store(self.temps[source], self.locals['return'])
        self.branch(self.exit_block)

    def emit_return_void(self):
        self.branch(self.exit_block)
Exemple #2
0
# Copy the argument to a local variable.  For reasons, that are 
# complicated, we copy the function argument to a local variable
# allocated on the stack (this makes mutations of the variable
# easier when looping).

n_var = builder.alloca(IntType(32), name='n')
builder.store(f_func.args[0], n_var)

# Allocate the result variable
total_var = builder.alloca(IntType(32), name='total')
builder.store(Constant(IntType(32), 0), total_var)

# Make a new basic-block for the loop test
loop_test_block = f_func.append_basic_block('looptest')
builder.branch(loop_test_block)
builder.position_at_end(loop_test_block)

# Perform the comparison
testvar = builder.icmp_signed('>', builder.load(n_var), Constant(IntType(32), 0))

# Make three blocks
loop_body_block = f_func.append_basic_block('loopbody')
loop_exit_block = f_func.append_basic_block('loopexit')

# Branch based on the test var
builder.cbranch(testvar, loop_body_block, loop_exit_block)

builder.position_at_end(loop_body_block)
tmp = builder.add(builder.load(total_var), builder.load(n_var))
builder.store(tmp, total_var)
tmp2 = builder.sub(builder.load(n_var), Constant(IntType(32), 1))
Exemple #3
0
class GenerateLLVM(object):
    def __init__(self):
        # Perform the basic LLVM initialization.  You need the following parts:
        #
        #    1.  A top-level Module object
        #    2.  A Function instance in which to insert code
        #    3.  A Builder instance to generate instructions
        #
        # Note: For project 5, we don't have any user-defined
        # functions so we're just going to emit all LLVM code into a top
        # level function void main() { ... }.   This will get changed later.

        self.module = Module('module')
        self.function = Function(self.module,
                                 FunctionType(void_type, []),
                                 name='main')

        self.block = self.function.append_basic_block('entry')
        self.builder = IRBuilder(self.block)

        # Dictionary that holds all of the global variable/function declarations.
        # Any declaration in the Gone source code is going to get an entry here
        self.vars = ChainMap()

        # Dictionary that holds all of the temporary registers created in
        # the intermediate code.
        self.temps = {}

        self.blocks = { }

        self.funcs = { }


        self.current_func = None

        # Initialize the runtime library functions (see below)
        self.declare_runtime_library()


    def declare_runtime_library(self):
        # Certain functions such as I/O and string handling are often easier
        # to implement in an external C library.  This method should make
        # the LLVM declarations for any runtime functions to be used
        # during code generation.    Please note that runtime function
        # functions are implemented in C in a separate file gonert.c

        self.runtime = {}

        # Declare printing functions
        self.runtime['_print_int'] = Function(self.module,
                                              FunctionType(void_type, [int_type]),
                                              name="_print_int")

        self.runtime['_print_float'] = Function(self.module,
                                                FunctionType(void_type, [float_type]),
                                                name="_print_float")

        self.runtime['_print_byte'] = Function(self.module,
                                                FunctionType(void_type, [byte_type]),
                                                name="_print_byte")

    def generate_code(self, ircode):
        # Given a sequence of SSA intermediate code tuples, generate LLVM
        # instructions using the current builder (self.builder).  Each
        # opcode tuple (opcode, args) is dispatched to a method of the
        # form self.emit_opcode(args)

        # first collect all the blocks
        for instr in ircode:
            if instr[0] == 'BLK':
                self.blocks[instr[1]] = self.function.append_basic_block(instr[1])


        for opcode, *args in ircode:
            if hasattr(self, 'emit_'+opcode):
                getattr(self, 'emit_'+opcode)(*args)
            else:
                print('Warning: No emit_'+opcode+'() method')

        # Add a return statement.  Note, at this point, we don't really have
        # user-defined functions so this is a bit of hack--it may be removed later.
        self.builder.ret_void()

    # ----------------------------------------------------------------------
    # Opcode implementation.   You must implement the opcodes.  A few
    # sample opcodes have been given to get you started.
    # ----------------------------------------------------------------------

    def emit_FUNCTION_END(self, f_name):

        if not self.block.is_terminated:
            self.builder.branch(self.return_block)

        self.builder.position_at_end(self.return_block)
        self.builder.ret(self.builder.load(self.return_var))


    def emit_FUNCTION(self, f_name, arguments, return_type):
        arguments = eval(arguments)
        argtypes = list(map(lambda z: z[0], arguments))

        f_func = Function(self.module,
                          FunctionType(
                            type_lookup[return_type],
                            argtypes
                          ),
                          name=f_name)
        self.current_func = f_func

        self.block = self.current_func.append_basic_block('entry')

        self.return_block = self.current_func.append_basic_block('return')
        self.return_var = self.builder.alloca(type_lookup[return_type], name='return')
        self.funcs[f_name] = self.current_func

    def emit_CALL(self, f_name, sources, target):
        #import pdb
        #pdb.set_trace()
        f = self.funcs[f_name]
        self.temps[target] = self.builder.call(f,
            [self.temps[r] for r in eval(sources)]
        )

    def emit_RETURN(self, var):
        self.builder.ret(self.vars[var])


    # Creation of literal values.  Simply define as LLVM constants.
    def emit_MOVI(self, value, target):
        self.temps[target] = Constant(int_type, value)

    def emit_MOVF(self, value, target):
        self.temps[target] = Constant(float_type, value)

    def emit_MOVB(self, value, target):
        self.temps[target] = Constant(byte_type, value)

    # Allocation of variables.  Declare as global variables and set to
    # a sensible initial value.
    def emit_VARI(self, name):
        var = GlobalVariable(self.module, int_type, name=name)
        var.initializer = Constant(int_type, 0)
        self.vars[name] = var

    def emit_VARF(self, name):
        var = GlobalVariable(self.module, float_type, name=name)
        var.initializer = Constant(float_type, 0)
        self.vars[name] = var

    def emit_VARB(self, name):
        var = GlobalVariable(self.module, byte_type, name=name)
        var.initializer = Constant(byte_type, 0)
        self.vars[name] = var

    def emit_ALLOCI(self, name):
        var = self.builder.alloca(IntType(32), name=name)
        self.builder.store(Constant(int_type, 0), var)
        self.vars[name] = var

    # Load/store instructions for variables.  Load needs to pull a
    # value from a global variable and store in a temporary. Store
    # goes in the opposite direction.
    def emit_LOADI(self, name, target):
        self.temps[target] = self.builder.load(self.vars[name], target)

    emit_LOADB = emit_LOADI
    emit_LOADF = emit_LOADI

    def emit_STOREI(self, source, target):
        self.builder.store(self.temps[source], self.vars[target])

    emit_STOREF = emit_STOREI
    emit_STOREB = emit_STOREI

    # Binary + operator
    def emit_ADDI(self, left, right, target):
        self.temps[target] = self.builder.add(self.temps[left], self.temps[right], target)

    # Binary + operator
    def emit_ADDF(self, left, right, target):
        self.temps[target] = self.builder.fadd(self.temps[left], self.temps[right], target)

    # Binary - operator
    def emit_SUBI(self, left, right, target):
        self.temps[target] = self.builder.sub(self.temps[left], self.temps[right], target)

    def emit_SUBF(self, left, right, target):
        self.temps[target] = self.builder.fsub(self.temps[left], self.temps[right], target)

    # Binary * operator
    def emit_MULI(self, left, right, target):
        self.temps[target] = self.builder.mul(self.temps[left], self.temps[right], target)

    def emit_MULF(self, left, right, target):
        self.temps[target] = self.builder.fmul(self.temps[left], self.temps[right], target)

    # Binary / operator
    def emit_DIVI(self, left, right, target):
        self.temps[target] = self.builder.sdiv(self.temps[left], self.temps[right], target)

    def emit_DIVF(self, left, right, target):
        self.temps[target] = self.builder.fdiv(self.temps[left], self.temps[right], target)

    def emit_AND(self, left, right, target):
        self.temps[target] = self.builder.and_(self.temps[left], self.temps[right], target)

    def emit_OR(self, left, right, target):
        self.temps[target] = self.builder.or_(self.temps[left], self.temps[right], target)

    def emit_CMPF(self, op, left, right, target):
        temp = self.builder.fcmp_ordered(op, self.temps[left], self.temps[right], 'temp')
        self.temps[target] = self.builder.zext(temp, int_type)

    def emit_CMPI(self, op, left, right, target):
        temp = self.builder.icmp_signed(op, self.temps[left], self.temps[right], 'temp')
        self.temps[target] = self.builder.zext(temp, int_type)

    def cast_to_int(self, value):
        return self.builder.zext(value, int_type)

    def cast_to_byte(self, value):
        return self.builder.trunc(value, IntType(1))

    # Print statements
    def emit_PRINTI(self, source):
        self.builder.call(self.runtime['_print_int'], [self.cast_to_int(self.temps[source])])

    def emit_PRINTF(self, source):
        self.builder.call(self.runtime['_print_float'], [self.temps[source]])

    def emit_PRINTB(self, source):
        self.builder.call(self.runtime['_print_byte'], [self.temps[source]])


    # conditionals and branches

    def emit_CJMP(self, target, true_branch, false_branch):
        self.builder.cbranch(self.cast_to_byte(self.temps[target]), self.blocks[true_branch], self.blocks[false_branch])

    def emit_JMP(self, target):
        self.builder.branch(self.blocks[target])

    def emit_BLK(self, target):
        self.builder.position_at_end(self.blocks[target])
Exemple #4
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    def _build_wrapper(self, library, name):
        """
        The LLVM IRBuilder code to create the gufunc wrapper.
        The *library* arg is the CodeLibrary to which the wrapper should
        be added.  The *name* arg is the name of the wrapper function being
        created.
        """
        intp_t = self.context.get_value_type(types.intp)
        fnty = self._wrapper_function_type()

        wrapper_module = library.create_ir_module('_gufunc_wrapper')
        func_type = self.call_conv.get_function_type(self.fndesc.restype,
                                                     self.fndesc.argtypes)
        fname = self.fndesc.llvm_func_name
        func = ir.Function(wrapper_module, func_type, name=fname)

        func.attributes.add("alwaysinline")
        wrapper = ir.Function(wrapper_module, fnty, name)
        # The use of weak_odr linkage avoids the function being dropped due
        # to the order in which the wrappers and the user function are linked.
        wrapper.linkage = 'weak_odr'
        arg_args, arg_dims, arg_steps, arg_data = wrapper.args
        arg_args.name = "args"
        arg_dims.name = "dims"
        arg_steps.name = "steps"
        arg_data.name = "data"

        builder = IRBuilder(wrapper.append_basic_block("entry"))
        loopcount = builder.load(arg_dims, name="loopcount")
        pyapi = self.context.get_python_api(builder)

        # Unpack shapes
        unique_syms = set()
        for grp in (self.sin, self.sout):
            for syms in grp:
                unique_syms |= set(syms)

        sym_map = {}
        for syms in self.sin:
            for s in syms:
                if s not in sym_map:
                    sym_map[s] = len(sym_map)

        sym_dim = {}
        for s, i in sym_map.items():
            sym_dim[s] = builder.load(
                builder.gep(arg_dims,
                            [self.context.get_constant(types.intp, i + 1)]))

        # Prepare inputs
        arrays = []
        step_offset = len(self.sin) + len(self.sout)
        for i, (typ, sym) in enumerate(
                zip(self.signature.args, self.sin + self.sout)):
            ary = GUArrayArg(self.context, builder, arg_args, arg_steps, i,
                             step_offset, typ, sym, sym_dim)
            step_offset += len(sym)
            arrays.append(ary)

        bbreturn = builder.append_basic_block('.return')

        # Prologue
        self.gen_prologue(builder, pyapi)

        # Loop
        with cgutils.for_range(builder, loopcount, intp=intp_t) as loop:
            args = [a.get_array_at_offset(loop.index) for a in arrays]
            innercall, error = self.gen_loop_body(builder, pyapi, func, args)
            # If error, escape
            cgutils.cbranch_or_continue(builder, error, bbreturn)

        builder.branch(bbreturn)
        builder.position_at_end(bbreturn)

        # Epilogue
        self.gen_epilogue(builder, pyapi)

        builder.ret_void()

        # Link
        library.add_ir_module(wrapper_module)
        library.add_linking_library(self.library)