implemented some missing libm functions too
diff --git a/aos/build/libgcc-additions/libgcc-additions.gypi b/aos/build/libgcc-additions/libgcc-additions.gypi
index 8090f7c..afa81f6 100644
--- a/aos/build/libgcc-additions/libgcc-additions.gypi
+++ b/aos/build/libgcc-additions/libgcc-additions.gypi
@@ -27,6 +27,8 @@
         '_bswapdi2.o',
         '<(compiler-rt)/lib/floatundisf.c',
         '<(compiler-rt)/lib/floatundidf.c',
+
+        'libm.c',
       ],
     },
   ],