Merge in trunk.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/wide-int@204436 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 10 insertions, 2 deletions

diff --git a/gcc/loop-iv.c b/gcc/loop-iv.c
index 60d5043d67a..6b5f82b16b1 100644
--- a/gcc/loop-iv.c
+++ b/gcc/loop-iv.c
@@ -436,7 +436,9 @@ iv_subreg (struct rtx_iv *iv, enum machine_mode mode)
       && !iv->first_special)
     {
       rtx val = get_iv_value (iv, const0_rtx);
-      val = lowpart_subreg (mode, val, iv->extend_mode);
+      val = lowpart_subreg (mode, val,
+			    iv->extend == IV_UNKNOWN_EXTEND
+			    ? iv->mode : iv->extend_mode);
 
       iv->base = val;
       iv->extend = IV_UNKNOWN_EXTEND;
@@ -476,8 +478,14 @@ iv_extend (struct rtx_iv *iv, enum iv_extend_code extend, enum machine_mode mode
       && !iv->first_special)
     {
       rtx val = get_iv_value (iv, const0_rtx);
+      if (iv->extend_mode != iv->mode
+	  && iv->extend != IV_UNKNOWN_EXTEND
+	  && iv->extend != extend)
+	val = lowpart_subreg (iv->mode, val, iv->extend_mode);
       val = simplify_gen_unary (iv_extend_to_rtx_code (extend), mode,
-				val, iv->extend_mode);
+				val,
+				iv->extend == extend
+				? iv->extend_mode : iv->mode);
       iv->base = val;
       iv->extend = IV_UNKNOWN_EXTEND;
       iv->mode = iv->extend_mode = mode;