diff -up flac-1.3.2/configure.ac.cflags flac-1.3.2/configure.ac

--- flac-1.3.2/configure.ac.cflags	2017-01-02 14:02:15.663046237 +0100

+++ flac-1.3.2/configure.ac	2017-01-02 14:04:20.718046015 +0100

@@ -390,7 +390,7 @@ if test "x$debug" = xtrue; then

 else

 	CPPFLAGS="-DNDEBUG $CPPFLAGS"

 	CFLAGS=$(echo "$CFLAGS" | sed 's/-O2//')

-	CFLAGS="-O3 -funroll-loops $CFLAGS"

+	CFLAGS="$user_cflags"

 fi

 XIPH_GCC_VERSION

@@ -400,7 +400,6 @@ if test x$ac_cv_c_compiler_gnu = xyes ;

 	CXXFLAGS="$CXXFLAGS -Wall -Wextra -Wcast-align -Wshadow -Wwrite-strings -Wctor-dtor-privacy -Wnon-virtual-dtor -Wreorder -Wsign-promo -Wundef " # -Wcast-qual -Wbad-function-cast -Wwrite-strings -Woverloaded-virtual -Wmissing-declarations

 	XIPH_ADD_CFLAGS([-Wdeclaration-after-statement])

-	XIPH_ADD_CFLAGS([-D_FORTIFY_SOURCE=2])

 	AC_LANG_PUSH([C++])

 	XIPH_ADD_CXXFLAGS([-Weffc++])

@@ -426,10 +425,6 @@ if test x$ac_cv_c_compiler_gnu = xyes ;

 		XIPH_ADD_CFLAGS([-fno-inline-small-functions])

 		fi

-	if test "x$asm_optimisation$sse_os" = "xyesyes" ; then

-		XIPH_ADD_CFLAGS([-msse2])

-		fi

-

 	fi

 case "$host_os" in