* expr.c (move_by_pieces): Set alignment for move to minimum of

        MOVE_MAX_PIECES mode alignment and the largest non-slow mode
        alignment, but not less than the original alignment.
        (move_by_pieces_ninsns): Same.
        (can_store_by_pieces): Similar for store with STORE_MAX_PIECES.
        (store_by_pieces_1): Same.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@85875 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 66 insertions, 13 deletions

diff --git a/gcc/expr.c b/gcc/expr.c
index 282bb9af57d..7d216aeb318 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -925,9 +925,22 @@ move_by_pieces (rtx to, rtx from, unsigned HOST_WIDE_INT len,
 	data.to_addr = copy_addr_to_reg (to_addr);
     }
 
-  if (! SLOW_UNALIGNED_ACCESS (word_mode, align)
-      || align > MOVE_MAX * BITS_PER_UNIT || align >= BIGGEST_ALIGNMENT)
-    align = MOVE_MAX * BITS_PER_UNIT;
+  tmode = mode_for_size (MOVE_MAX_PIECES * BITS_PER_UNIT, MODE_INT, 1);
+  if (align >= GET_MODE_ALIGNMENT (tmode))
+    align = GET_MODE_ALIGNMENT (tmode);
+  else
+    {
+      enum machine_mode xmode;
+
+      for (tmode = GET_CLASS_NARROWEST_MODE (MODE_INT), xmode = tmode;
+	   tmode != VOIDmode;
+	   xmode = tmode, tmode = GET_MODE_WIDER_MODE (tmode))
+	if (GET_MODE_SIZE (tmode) > MOVE_MAX_PIECES
+	    || SLOW_UNALIGNED_ACCESS (tmode, align))
+	  break;
+
+      align = MAX (align, GET_MODE_ALIGNMENT (xmode));
+    }
 
   /* First move what we can in the largest integer mode, then go to
      successively smaller modes.  */
@@ -992,14 +1005,28 @@ move_by_pieces_ninsns (unsigned HOST_WIDE_INT l, unsigned int align,
 		       unsigned int max_size)
 {
   unsigned HOST_WIDE_INT n_insns = 0;
+  enum machine_mode tmode;
 
-  if (! SLOW_UNALIGNED_ACCESS (word_mode, align)
-      || align > MOVE_MAX * BITS_PER_UNIT || align >= BIGGEST_ALIGNMENT)
-    align = MOVE_MAX * BITS_PER_UNIT;
+  tmode = mode_for_size (MOVE_MAX_PIECES * BITS_PER_UNIT, MODE_INT, 1);
+  if (align >= GET_MODE_ALIGNMENT (tmode))
+    align = GET_MODE_ALIGNMENT (tmode);
+  else
+    {
+      enum machine_mode tmode, xmode;
+
+      for (tmode = GET_CLASS_NARROWEST_MODE (MODE_INT), xmode = tmode;
+	   tmode != VOIDmode;
+	   xmode = tmode, tmode = GET_MODE_WIDER_MODE (tmode))
+	if (GET_MODE_SIZE (tmode) > MOVE_MAX_PIECES
+	    || SLOW_UNALIGNED_ACCESS (tmode, align))
+	  break;
+
+      align = MAX (align, GET_MODE_ALIGNMENT (xmode));
+    }
 
   while (max_size > 1)
     {
-      enum machine_mode mode = VOIDmode, tmode;
+      enum machine_mode mode = VOIDmode;
       enum insn_code icode;
 
       for (tmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
@@ -1999,9 +2026,22 @@ can_store_by_pieces (unsigned HOST_WIDE_INT len,
   if (! STORE_BY_PIECES_P (len, align))
     return 0;
 
-  if (! SLOW_UNALIGNED_ACCESS (word_mode, align)
-      || align > MOVE_MAX * BITS_PER_UNIT || align >= BIGGEST_ALIGNMENT)
-    align = MOVE_MAX * BITS_PER_UNIT;
+  tmode = mode_for_size (STORE_MAX_PIECES * BITS_PER_UNIT, MODE_INT, 1);
+  if (align >= GET_MODE_ALIGNMENT (tmode))
+    align = GET_MODE_ALIGNMENT (tmode);
+  else
+    {
+      enum machine_mode xmode;
+
+      for (tmode = GET_CLASS_NARROWEST_MODE (MODE_INT), xmode = tmode;
+	   tmode != VOIDmode;
+	   xmode = tmode, tmode = GET_MODE_WIDER_MODE (tmode))
+	if (GET_MODE_SIZE (tmode) > STORE_MAX_PIECES
+	    || SLOW_UNALIGNED_ACCESS (tmode, align))
+	  break;
+
+      align = MAX (align, GET_MODE_ALIGNMENT (xmode));
+    }
 
   /* We would first store what we can in the largest integer mode, then go to
      successively smaller modes.  */
@@ -2201,9 +2241,22 @@ store_by_pieces_1 (struct store_by_pieces *data ATTRIBUTE_UNUSED,
 	data->to_addr = copy_addr_to_reg (to_addr);
     }
 
-  if (! SLOW_UNALIGNED_ACCESS (word_mode, align)
-      || align > MOVE_MAX * BITS_PER_UNIT || align >= BIGGEST_ALIGNMENT)
-    align = MOVE_MAX * BITS_PER_UNIT;
+  tmode = mode_for_size (STORE_MAX_PIECES * BITS_PER_UNIT, MODE_INT, 1);
+  if (align >= GET_MODE_ALIGNMENT (tmode))
+    align = GET_MODE_ALIGNMENT (tmode);
+  else
+    {
+      enum machine_mode xmode;
+
+      for (tmode = GET_CLASS_NARROWEST_MODE (MODE_INT), xmode = tmode;
+	   tmode != VOIDmode;
+	   xmode = tmode, tmode = GET_MODE_WIDER_MODE (tmode))
+	if (GET_MODE_SIZE (tmode) > STORE_MAX_PIECES
+	    || SLOW_UNALIGNED_ACCESS (tmode, align))
+	  break;
+
+      align = MAX (align, GET_MODE_ALIGNMENT (xmode));
+    }
 
   /* First store what we can in the largest integer mode, then go to
      successively smaller modes.  */