add -frounding-math to build
diff --git a/configure b/configure
index df1d301..4ef6ccc 100755
--- a/configure
+++ b/configure
@@ -192,6 +192,7 @@
 || tryflag CFLAGS_C99FSE -fno-builtin
 tryflag CFLAGS_C99FSE -fexcess-precision=standard \
 || tryflag CFLAGS_C99FSE -ffloat-store
+tryflag CFLAGS_C99FSE -frounding-math
 
 #
 # Setup basic default CFLAGS: debug, optimization, and -pipe