enable 3dnow optimizations by default

configure.in

@@ -196,15 +196,10 @@ if test x$sse_os = xtrue ; then
 AC_DEFINE(FLAC__SSE_OS)
 fi
 
-AC_ARG_ENABLE(3dnow,
-[  --enable-3dnow                 Enable 3DNOW! support],
-[case "${enableval}" in
-	yes) use_3dnow=true ;;
-	no)  use_3dnow=false ;;
-	*) AC_MSG_ERROR(bad value ${enableval} for --enable-3dnow) ;;
-esac],[use_3dnow=false])
-AM_CONDITIONAL(FLaC__USE_3DNOW, test x$use_3dnow = xtrue)
-if test x$use_3dnow = xtrue ; then
+use_3dnow=yes
+AC_ARG_ENABLE(3dnow, [  --disable-3dnow                 Disable 3DNOW! optimizations], use_3dnow=no, use_3dnow=yes)
+AM_CONDITIONAL(FLaC__USE_3DNOW, test x$use_3dnow = xyes)
+if test x$use_3dnow = xyes ; then
 AC_DEFINE(FLAC__USE_3DNOW)
 fi
 

src/libFLAC/Makefile.lite

@@ -29,7 +29,7 @@ else
 ifeq ($(SOLARIS_BUILD),yes)
 DEFINES = -DFLAC__NO_NASM -DFLAC__ALIGN_MALLOC_DATA
 else
-DEFINES = -DFLAC__CPU_IA32 -DFLAC__HAS_NASM -DFLAC__ALIGN_MALLOC_DATA
+DEFINES = -DFLAC__CPU_IA32 -DFLAC__USE_3DNOW -DFLAC__HAS_NASM -DFLAC__ALIGN_MALLOC_DATA
 endif
 endif
 INCLUDES = -I./include -I$(topdir)/include