when building for arm as thumb2 code, also request assembly as thumb

all assembly is now thumb2-compatible. on existing targets this is at
best a size optimization, but it will also facilitate porting to
thumb2-isa-only arm variants.

diff --git a/configure b/configure
index 81e90f790336e5d22cf16924f3f146c2e68e2cb8..c2db298ce95f71afce00efae02e8f164ec47271b 100755 (executable)
--- a/configure
+++ b/configure
@@ -602,6 +602,10 @@ trycppif __ILP32__ "$t" && ARCH=x32
 fi
 
 if test "$ARCH" = "arm" ; then
+if trycppif __thumb2__ "$t" ; then
+tryflag CFLAGS_AUTO -Wa,-mimplicit-it=always
+tryflag CFLAGS_AUTO -Wa,-mthumb
+fi
 trycppif __ARMEB__ "$t" && SUBARCH=${SUBARCH}eb
 trycppif __ARM_PCS_VFP "$t" && SUBARCH=${SUBARCH}hf
 # Versions of clang up until at least 3.8 have the wrong constraint codes