re PR middle-end/23467 (alignment of member doesn't always carry over to alignment of struct.)

gcc:
        PR middle-end/23467
        * stor-layout.c (finalize_type_size): Dont override
        existing alignment with a smaller alignment from the mode.
testsuite:
        PR middle-end/23467
        * gcc.c-torture/execute/pr23467.c: New test.

From-SVN: r103394

gcc/ChangeLog

+2005-08-23  J"orn Rennecke <joern.rennecke@st.com>
+
+	PR middle-end/23467
+	* stor-layout.c (finalize_type_size): Dont override
+	existing alignment with a smaller alignment from the mode.
+
 2005-08-23  Sebastian Pop  <pop@cri.ensmp.fr>
 
 	* lambda-code.c (lambda_vector_lexico_pos): Moved...

gcc/stor-layout.c

@@ -1407,8 +1407,15 @@ finalize_type_size (tree type)
 	      && TREE_CODE (type) != QUAL_UNION_TYPE
 	      && TREE_CODE (type) != ARRAY_TYPE)))
     {
-      TYPE_ALIGN (type) = GET_MODE_ALIGNMENT (TYPE_MODE (type));
-      TYPE_USER_ALIGN (type) = 0;
+      unsigned mode_align = GET_MODE_ALIGNMENT (TYPE_MODE (type));
+
+      /* Don't override a larger alignment requirement coming from a user
+	 alignment of one of the fields.  */
+      if (mode_align >= TYPE_ALIGN (type))
+	{
+	  TYPE_ALIGN (type) = mode_align;
+	  TYPE_USER_ALIGN (type) = 0;
+	}
     }
 
   /* Do machine-dependent extra alignment.  */

gcc/testsuite/ChangeLog

+2005-08-23  J"orn Rennecke <joern.rennecke@st.com>
+
+	PR middle-end/23467
+	* gcc.c-torture/execute/pr23467.c: New test.
+
 2005-08-23  Jakub Jelinek  <jakub@redhat.com>
 
 	PR tree-optimization/22043

gcc/testsuite/gcc.c-torture/execute/pr23467.c

+struct s1
+{
+  int __attribute__ ((aligned (8))) a;
+};
+
+struct
+{
+  char c;
+  struct s1 m;
+} v;
+
+int
+main (void)
+{
+  if ((int)&v.m & 7)
+    abort ();
+  exit (0);
+}