Index: lib/builtins/extendhfsf2.c
===================================================================
--- lib/builtins/extendhfsf2.c
+++ lib/builtins/extendhfsf2.c
@@ -12,9 +12,15 @@
 #define DST_SINGLE
 #include "fp_extend_impl.inc"
 
+#ifdef _MSC_VER
+#define __NOINLINE __declspec(noinline)
+#else
+#define __NOINLINE __attribute__((noinline))
+#endif
+
 // Use a forwarding definition and noinline to implement a poor man's alias,
 // as there isn't a good cross-platform way of defining one.
-COMPILER_RT_ABI __attribute__((noinline)) float __extendhfsf2(uint16_t a) {
+COMPILER_RT_ABI __NOINLINE float __extendhfsf2(uint16_t a) {
     return __extendXfYf2__(a);
 }
 
Index: lib/builtins/int_lib.h
===================================================================
--- lib/builtins/int_lib.h
+++ lib/builtins/int_lib.h
@@ -35,7 +35,7 @@
 # define COMPILER_RT_ABI __attribute__((pcs("aapcs")))
 #else
 # define ARM_EABI_FNALIAS(aeabi_name, name)
-# if defined(__arm__) && defined(_WIN32)
+# if defined(__arm__) && defined(_WIN32) && !defined(_MSC_VER)
 #   define COMPILER_RT_ABI __attribute__((pcs("aapcs")))
 # else
 #   define COMPILER_RT_ABI
Index: lib/builtins/int_util.h
===================================================================
--- lib/builtins/int_util.h
+++ lib/builtins/int_util.h
@@ -19,16 +19,24 @@
 #ifndef INT_UTIL_H
 #define INT_UTIL_H
 
+#ifdef _MSC_VER
+#define __NORETURN(x) __declspec(noreturn) x
+#define __UNUSED
+#else
+#define __NORETURN(x) x __attribute__((noreturn))
+#define __UNUSED __attribute__((unused))
+#endif
+
 /** \brief Trigger a program abort (or panic for kernel code). */
 #define compilerrt_abort() compilerrt_abort_impl(__FILE__, __LINE__, \
                                                  __func__)
 
-void compilerrt_abort_impl(const char *file, int line,
-                           const char *function) __attribute__((noreturn));
+__NORETURN(void compilerrt_abort_impl(const char *file, int line,
+                           const char *function));
 
 #define COMPILE_TIME_ASSERT(expr) COMPILE_TIME_ASSERT1(expr, __COUNTER__)
 #define COMPILE_TIME_ASSERT1(expr, cnt) COMPILE_TIME_ASSERT2(expr, cnt)
 #define COMPILE_TIME_ASSERT2(expr, cnt) \
-    typedef char ct_assert_##cnt[(expr) ? 1 : -1] __attribute__((unused))
+    typedef char ct_assert_##cnt[(expr) ? 1 : -1] __UNUSED
 
 #endif /* INT_UTIL_H */
Index: lib/builtins/truncsfhf2.c
===================================================================
--- lib/builtins/truncsfhf2.c
+++ lib/builtins/truncsfhf2.c
@@ -11,9 +11,15 @@
 #define DST_HALF
 #include "fp_trunc_impl.inc"
 
+#ifdef _MSC_VER
+#define __NOINLINE __declspec(noinline)
+#else
+#define __NOINLINE __attribute__((noinline))
+#endif
+
 // Use a forwarding definition and noinline to implement a poor man's alias,
 // as there isn't a good cross-platform way of defining one.
-COMPILER_RT_ABI __attribute__((noinline)) uint16_t __truncsfhf2(float a) {
+COMPILER_RT_ABI __NOINLINE uint16_t __truncsfhf2(float a) {
     return __truncXfYf2__(a);
 }