(convert_move): When emit multiword conversion, force FROM into a new

pseudo-reg if it overlaps TO.

From-SVN: r8593

1 files changed, 6 insertions, 0 deletions

diff --git a/gcc/expr.c b/gcc/expr.c
index 4c2ac54..f109293 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -916,6 +916,12 @@ convert_move (to, from, unsignedp)
       /* No special multiword conversion insn; do it by hand.  */
       start_sequence ();
 
+      /* Since we will turn this into a no conflict block, we must ensure
+	 that the source does not overlap the target.  */
+
+      if (reg_overlap_mentioned_p (to, from))
+	from = force_reg (from_mode, from);
+
       /* Get a copy of FROM widened to a word, if necessary.  */
       if (GET_MODE_BITSIZE (from_mode) < BITS_PER_WORD)
 	lowpart_mode = word_mode;