add invariant load

add related test

llvm/core.py

@@ -1866,13 +1866,17 @@ class Builder(object):
         check_is_value(ptr)
         return _make_value(_core.LLVMBuildFree(self.ptr, ptr.ptr))
 
-    def load(self, ptr, name="", align=0, volatile=False):
+    def load(self, ptr, name="", align=0, volatile=False, invariant=False):
         check_is_value(ptr)
         inst = _make_value(_core.LLVMBuildLoad(self.ptr, ptr.ptr, name))
         if align:
             _core.LLVMLdSetAlignment(inst.ptr, align)
         if volatile:
             inst.set_volatile(volatile)
+        if invariant:
+            mod = self.basic_block.function.module
+            md = MetaData.get(mod, []) # empty metadata node
+            inst.set_metadata('invariant.load', md)
         return inst
 
     def store(self, value, ptr, align=0, volatile=False):

test/metadata.py

@@ -23,6 +23,20 @@ class TestMetaData(unittest.TestCase):
 
         self.assertIn('!nontemporal', str(loadinst))
 
+    def test_meta_load_invariant(self):
+        module = Module.new('test_meta_load_invariant')
+        func = module.add_function(Type.function(Type.void(), []),
+                                   name='test_load_invariant')
+        bldr = Builder.new(func.append_basic_block('entry'))
+        addr = Constant.int(Type.int(), 0xdeadbeef)
+        loadinst = bldr.load(bldr.inttoptr(addr, Type.pointer(Type.int(8))),
+                             invariant=True)
+
+        bldr.ret_void()
+        module.verify()
+
+        self.assertIn('!invariant.load', str(loadinst))
+
 if __name__ == '__main__':
     unittest.main()