diff --git a/lib/builtins/assembly.h b/lib/builtins/assembly.h
new file mode 100644
index 0000000..78efe3a
--- /dev/null
+++ b/lib/builtins/assembly.h
@@ -0,0 +1,146 @@
+/* ===-- assembly.h - compiler-rt assembler support macros -----------------===
+ *
+ *                     The LLVM Compiler Infrastructure
+ *
+ * This file is dual licensed under the MIT and the University of Illinois Open
+ * Source Licenses. See LICENSE.TXT for details.
+ *
+ * ===----------------------------------------------------------------------===
+ *
+ * This file defines macros for use in compiler-rt assembler source.
+ * This file is not part of the interface of this library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+#ifndef COMPILERRT_ASSEMBLY_H
+#define COMPILERRT_ASSEMBLY_H
+
+#if defined(__POWERPC__) || defined(__powerpc__) || defined(__ppc__)
+#define SEPARATOR @
+#else
+#define SEPARATOR ;
+#endif
+
+#if defined(__APPLE__)
+#define HIDDEN(name) .private_extern name
+#define LOCAL_LABEL(name) L_##name
+// tell linker it can break up file at label boundaries
+#define FILE_LEVEL_DIRECTIVE .subsections_via_symbols
+#define SYMBOL_IS_FUNC(name)
+#elif defined(__ELF__)
+#define HIDDEN(name) .hidden name
+#define LOCAL_LABEL(name) .L_##name
+#define FILE_LEVEL_DIRECTIVE
+#if defined(__arm__)
+#define SYMBOL_IS_FUNC(name) .type name,%function
+#else
+#define SYMBOL_IS_FUNC(name) .type name,@function
+#endif
+#else
+#define HIDDEN_DIRECTIVE(name)
+#define LOCAL_LABEL(name) .L ## name
+#define SYMBOL_IS_FUNC(name)                                                   \
+  .def name SEPARATOR                                                          \
+    .scl 3 SEPARATOR                                                           \
+    .type 32 SEPARATOR                                                         \
+  .endef
+#define FILE_LEVEL_DIRECTIVE
+#endif
+
+#if defined(__arm__)
+#ifndef __ARM_ARCH
+#if defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) ||                     \
+    defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) ||                    \
+    defined(__ARM_ARCH_7EM__)
+#define __ARM_ARCH 7
+#endif
+#endif
+
+#ifndef __ARM_ARCH
+#if defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) ||                     \
+    defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) ||                    \
+    defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6ZM__)
+#define __ARM_ARCH 6
+#endif
+#endif
+
+#ifndef __ARM_ARCH
+#if defined(__ARM_ARCH_5__) || defined(__ARM_ARCH_5T__) ||                     \
+    defined(__ARM_ARCH_5TE__) || defined(__ARM_ARCH_5TEJ__)
+#define __ARM_ARCH 5
+#endif
+#endif
+
+#ifndef __ARM_ARCH
+#define __ARM_ARCH 4
+#endif
+
+#if defined(__ARM_ARCH_4T__) || __ARM_ARCH >= 5
+#define ARM_HAS_BX
+#endif
+#if !defined(__ARM_FEATURE_CLZ) &&                                             \
+    (__ARM_ARCH >= 6 || (__ARM_ARCH == 5 && !defined(__ARM_ARCH_5__)))
+#define __ARM_FEATURE_CLZ
+#endif
+
+#ifdef ARM_HAS_BX
+#define JMP(r) bx r
+#define JMPc(r, c) bx##c r
+#else
+#define JMP(r) mov pc, r
+#define JMPc(r, c) mov##c pc, r
+#endif
+#endif
+
+#define GLUE2(a, b) a##b
+#define GLUE(a, b) GLUE2(a, b)
+#define SYMBOL_NAME(name) GLUE(__USER_LABEL_PREFIX__, name)
+
+#ifdef VISIBILITY_HIDDEN
+#define DECLARE_SYMBOL_VISIBILITY(name)                                        \
+  HIDDEN(SYMBOL_NAME(name)) SEPARATOR
+#else
+#define DECLARE_SYMBOL_VISIBILITY(name)
+#endif
+
+#define DEFINE_COMPILERRT_FUNCTION(name)                                       \
+  FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
+  .globl SYMBOL_NAME(name) SEPARATOR                                           \
+  SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
+  DECLARE_SYMBOL_VISIBILITY(name)                                              \
+  SYMBOL_NAME(name):
+
+#define DEFINE_COMPILERRT_PRIVATE_FUNCTION(name)                               \
+  FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
+  .globl SYMBOL_NAME(name) SEPARATOR                                           \
+  SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
+  HIDDEN(SYMBOL_NAME(name)) SEPARATOR                                          \
+  SYMBOL_NAME(name):
+
+#define DEFINE_COMPILERRT_PRIVATE_FUNCTION_UNMANGLED(name)                     \
+  .globl name SEPARATOR                                                        \
+  SYMBOL_IS_FUNC(name) SEPARATOR                                               \
+  HIDDEN(name) SEPARATOR                                                       \
+  name:
+
+#define DEFINE_COMPILERRT_FUNCTION_ALIAS(name, target)                         \
+  .globl SYMBOL_NAME(name) SEPARATOR                                           \
+  SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
+  .set SYMBOL_NAME(name), SYMBOL_NAME(target) SEPARATOR
+
+#if defined(__ARM_EABI__)
+#define DEFINE_AEABI_FUNCTION_ALIAS(aeabi_name, name)                          \
+  DEFINE_COMPILERRT_FUNCTION_ALIAS(aeabi_name, name)
+#else
+#define DEFINE_AEABI_FUNCTION_ALIAS(aeabi_name, name)
+#endif
+
+#ifdef __ELF__
+#define END_COMPILERRT_FUNCTION(name)                                          \
+  .size SYMBOL_NAME(name), . - SYMBOL_NAME(name)
+#else
+#define END_COMPILERRT_FUNCTION(name)
+#endif
+
+#endif /* COMPILERRT_ASSEMBLY_H */