re PR rtl-optimization/21041 (ICE: output_operand: Cannot decompose address)

	PR rtl-optimization/21041
	* reload.c (find_reloads_subreg_address): Replace paradoxical
	subreg of MEM by widened access only if the resulting memory
	is properly aligned, even on !STRICT_ALIGNMENT targets.

	PR rtl-optimization/21041
	* gcc.dg/pr21041.c: New test.

From-SVN: r108760

gcc/ChangeLog

+2005-12-18  Ulrich Weigand  <uweigand@de.ibm.com>
+
+	PR rtl-optimization/21041
+	* reload.c (find_reloads_subreg_address): Replace paradoxical
+	subreg of MEM by widened access only if the resulting memory
+	is properly aligned, even on !STRICT_ALIGNMENT targets.
+
 2005-12-18  Andreas Krebbel  <krebbel1@de.ibm.com>
 
 	* tree-cfg.c (tree_flow_call_edges_add): Check for empty basic blocks.

gcc/reload.c

@@ -5911,7 +5911,7 @@ find_reloads_subreg_address (rtx x, int force_replace, int opnum,
 	      /* If this was a paradoxical subreg that we replaced, the
 		 resulting memory must be sufficiently aligned to allow
 		 us to widen the mode of the memory.  */
-	      if (outer_size > inner_size && STRICT_ALIGNMENT)
+	      if (outer_size > inner_size)
 		{
 		  rtx base;
 

gcc/testsuite/ChangeLog

+2005-12-18  Ulrich Weigand  <uweigand@de.ibm.com>
+
+	PR rtl-optimization/21041
+	* gcc.dg/pr21041.c: New test.
+
 2005-12-18  Andreas Krebbel  <krebbel1@de.ibm.com>
 
 	* gcc.dg/20051201-1.c: New test.

gcc/testsuite/gcc.dg/pr21041.c

+
+/* { dg-do compile { target fpic } } */
+/* { dg-options "-O2 -fPIC" } */
+
+struct args
+{
+  short int matrix[8][8];
+  char **current;
+};
+
+int test (struct args *args, char *init, int a, int b)
+{
+  int i, j, k;
+
+  if (!args || a > b || a < 0)
+    return -1;
+
+  for (i = 0; i < 2; i++)
+    {
+      char *dest = *args->current;
+      char *p = dest;
+
+      for (j = 0; j < 8; j++)
+        *p++ = *init++;
+
+      for (k = 0; k < 8; k++)
+        {
+          short int *blockvals = &args->matrix[k][0];
+          dest[0] += blockvals[0];
+          dest[1] += blockvals[1];
+          dest[2] += blockvals[2];
+          dest[3] += blockvals[3];
+          dest[4] += blockvals[4];
+          dest[5] += blockvals[5];
+          dest[6] += blockvals[6];
+          dest[7] += blockvals[7];
+       }
+    }
+
+  return 1;
+}
+