Adding missing files

llvm/control_flow.py

+import llvmlite.ir as ir
+
+
+class Loop:
+    def __init__(self, builder, start_val, stop_val, step_val=1, loop_name='loop', phi_name="_phi"):
+        self.builder = builder
+        self.start_val = start_val
+        self.stop_val = stop_val
+        self.step_val = step_val
+        self.loop_name = loop_name
+        self.phi_name = phi_name
+
+    def __enter__(self):
+        self.loop_end, self.after, phi = self._for_loop(self.start_val, self.stop_val, self.step_val, self.loop_name,
+                                                        self.phi_name)
+        return phi
+
+    def _for_loop(self, start_val, stop_val, step_val, loop_name, phi_name):
+        # TODO size of int??? unisgned???
+        integer = ir.IntType(64)
+
+        # Loop block
+        pre_loop_bb = self.builder.block
+        loop_bb = self.builder.append_basic_block(name='loop_' + loop_name)
+
+        self.builder.branch(loop_bb)
+
+        # Insert an explicit fall through from the current block to loop_bb
+        self.builder.position_at_start(loop_bb)
+
+        # Add phi
+        phi = self.builder.phi(integer, name=phi_name)
+        phi.add_incoming(start_val, pre_loop_bb)
+
+        loop_end_bb = self.builder.append_basic_block(name=loop_name + "_end_bb")
+        self.builder.position_at_start(loop_end_bb)
+
+        next_var = self.builder.add(phi, step_val, name=loop_name + '_next_it')
+        cond = self.builder.icmp_unsigned('<', next_var, stop_val, name=loop_name + "_cond")
+
+        after_bb = self.builder.append_basic_block(name=loop_name + "_after_bb")
+
+        self.builder.cbranch(cond, loop_bb, after_bb)
+        phi.add_incoming(next_var, loop_end_bb)
+
+        self.builder.position_at_end(loop_bb)
+
+        return loop_end_bb, after_bb, phi
+
+    def __exit__(self, exc_type, exc, exc_tb):
+        self.builder.branch(self.loop_end)
+        self.builder.position_at_end(self.after)