re PR tree-optimization/43188 ("error: alignment of array elements is greater than element size")

2010-02-26  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/43188
	* tree-vect-stmts.c (get_vectype_for_scalar_type): Do not build
	vector types of over-aligned element type.

	* gcc.c-torture/compile/pr43188.c: New testcase.

From-SVN: r157088

gcc/ChangeLog

+2010-02-26  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/43188
+	* tree-vect-stmts.c (get_vectype_for_scalar_type): Do not build
+	vector types of over-aligned element type.
+
 2010-02-26  Uros Bizjak  <ubizjak@gmail.com>
 
 	PR target/43175

gcc/testsuite/ChangeLog

+2010-02-26  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/43188
+	* gcc.c-torture/compile/pr43188.c: New testcase.
+
 2010-02-26  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR target/43175

gcc/testsuite/gcc.c-torture/compile/pr43188.c

+int *__attribute__((__aligned__(16))) *p;
+
+int main (void)
+{
+  return **p;
+}

gcc/tree-vect-stmts.c

@@ -4405,13 +4405,18 @@ tree
 get_vectype_for_scalar_type (tree scalar_type)
 {
   enum machine_mode inner_mode = TYPE_MODE (scalar_type);
-  int nbytes = GET_MODE_SIZE (inner_mode);
+  unsigned int nbytes = GET_MODE_SIZE (inner_mode);
   int nunits;
   tree vectype;
 
   if (nbytes == 0 || nbytes >= UNITS_PER_SIMD_WORD (inner_mode))
     return NULL_TREE;
 
+  /* We can't build a vector type of elements with alignment bigger than
+     their size.  */
+  if (nbytes < TYPE_ALIGN_UNIT (scalar_type))
+    return NULL_TREE;
+
   /* FORNOW: Only a single vector size per mode (UNITS_PER_SIMD_WORD)
      is expected.  */
   nunits = UNITS_PER_SIMD_WORD (inner_mode) / nbytes;