expr.c (clear_storage): Validate CONST0_RTX extant.

        * expr.c (clear_storage): Validate CONST0_RTX extant.  Special case
        complex modes.

From-SVN: r92615

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index db26b3a7db19772fb88f342faa66b33825fc872f..4e9c2834539763960934769d1bad20571566b656 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2004-12-25  Richard Henderson  <rth@redhat.com>
+
+       * expr.c (clear_storage): Validate CONST0_RTX extant.  Special case
+       complex modes.
+
 2004-12-25  Zdenek Dvorak  <dvorakz@suse.cz>
 
        PR rtl-optimization/19078

diff --git a/gcc/expr.c b/gcc/expr.c
index f602306d3e52bcfaae0cd66e33563533f95457df..6782feb0bfc230309aad51e9dd2c9f20ddcbd107 100644 (file)
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -159,6 +159,7 @@ static void emit_single_push_insn (enum machine_mode, rtx, tree);
 #endif
 static void do_tablejump (rtx, enum machine_mode, rtx, rtx, rtx);
 static rtx const_vector_from_tree (tree);
+static void write_complex_part (rtx, rtx, bool);
 
 /* Record for each mode whether we can move a register directly to or
    from an object of that mode in memory.  If we can't, we won't try
@@ -2405,30 +2406,48 @@ store_by_pieces_2 (rtx (*genfun) (rtx, ...), enum machine_mode mode,
 rtx
 clear_storage (rtx object, rtx size)
 {
-  rtx retval = 0;
-  unsigned int align = (MEM_P (object) ? MEM_ALIGN (object)
-                       : GET_MODE_ALIGNMENT (GET_MODE (object)));
+  enum machine_mode mode = GET_MODE (object);
+  unsigned int align;
 
   /* If OBJECT is not BLKmode and SIZE is the same size as its mode,
      just move a zero.  Otherwise, do this a piece at a time.  */
-  if (GET_MODE (object) != BLKmode
+  if (mode != BLKmode
       && GET_CODE (size) == CONST_INT
-      && INTVAL (size) == (HOST_WIDE_INT) GET_MODE_SIZE (GET_MODE (object)))
-    emit_move_insn (object, CONST0_RTX (GET_MODE (object)));
-  else
+      && INTVAL (size) == (HOST_WIDE_INT) GET_MODE_SIZE (mode))
     {
-      if (size == const0_rtx)
-       ;
-      else if (GET_CODE (size) == CONST_INT
-         && CLEAR_BY_PIECES_P (INTVAL (size), align))
-       clear_by_pieces (object, INTVAL (size), align);
-      else if (clear_storage_via_clrmem (object, size, align))
-       ;
-      else
-       retval = clear_storage_via_libcall (object, size);
+      rtx zero = CONST0_RTX (mode);
+      if (zero != NULL)
+       {
+         emit_move_insn (object, zero);
+         return NULL;
+       }
+
+      if (COMPLEX_MODE_P (mode))
+       {
+         zero = CONST0_RTX (GET_MODE_INNER (mode));
+         if (zero != NULL)
+           {
+             write_complex_part (object, zero, 0);
+             write_complex_part (object, zero, 1);
+             return NULL;
+           }
+       }
     }
 
-  return retval;
+  if (size == const0_rtx)
+    return NULL;
+
+  align = MEM_ALIGN (object);
+
+  if (GET_CODE (size) == CONST_INT
+      && CLEAR_BY_PIECES_P (INTVAL (size), align))
+    clear_by_pieces (object, INTVAL (size), align);
+  else if (clear_storage_via_clrmem (object, size, align))
+    ;
+  else
+    return clear_storage_via_libcall (object, size);
+
+  return NULL;
 }
 
 /* A subroutine of clear_storage.  Expand a clrmem pattern;