re PR testsuite/63175 (FAIL: gcc.dg/vect/costmodel/ppc/costmodel-bb-slp-9a.c…

re PR testsuite/63175 (FAIL: gcc.dg/vect/costmodel/ppc/costmodel-bb-slp-9a.c scan-tree-dump-times slp2" basic block vectorized using SLP" 1)

2015-02-27  Richard Biener  <rguenther@suse.de>

	PR middle-end/63175
	* builtins.c (get_object_alignment_2): Make sure to re-apply
	the ANDed mask after recursing to its operand gets us a new
	misalignment bit position.

From-SVN: r221043

gcc/ChangeLog

+2015-02-27  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/63175
+	* builtins.c (get_object_alignment_2): Make sure to re-apply
+	the ANDed mask after recursing to its operand gets us a new
+	misalignment bit position.
+
 2015-02-26  Jan Hubicka  <hubicka@ucw.cz>
 	    Martin Liska  <mliska@suse.cz>
 

gcc/builtins.c

@@ -359,13 +359,15 @@ get_object_alignment_2 (tree exp, unsigned int *alignp,
       tree addr = TREE_OPERAND (exp, 0);
       unsigned ptr_align;
       unsigned HOST_WIDE_INT ptr_bitpos;
+      unsigned HOST_WIDE_INT ptr_bitmask = ~0;
 
+      /* If the address is explicitely aligned, handle that.  */
       if (TREE_CODE (addr) == BIT_AND_EXPR
 	  && TREE_CODE (TREE_OPERAND (addr, 1)) == INTEGER_CST)
 	{
-	  align = (TREE_INT_CST_LOW (TREE_OPERAND (addr, 1))
-		    & -TREE_INT_CST_LOW (TREE_OPERAND (addr, 1)));
-	  align *= BITS_PER_UNIT;
+	  ptr_bitmask = TREE_INT_CST_LOW (TREE_OPERAND (addr, 1));
+	  ptr_bitmask *= BITS_PER_UNIT;
+	  align = ptr_bitmask & -ptr_bitmask;
 	  addr = TREE_OPERAND (addr, 0);
 	}
 
@@ -373,6 +375,9 @@ get_object_alignment_2 (tree exp, unsigned int *alignp,
 	= get_pointer_alignment_1 (addr, &ptr_align, &ptr_bitpos);
       align = MAX (ptr_align, align);
 
+      /* Re-apply explicit alignment to the bitpos.  */
+      ptr_bitpos &= ptr_bitmask;
+
       /* The alignment of the pointer operand in a TARGET_MEM_REF
 	 has to take the variable offset parts into account.  */
       if (TREE_CODE (exp) == TARGET_MEM_REF)