re PR tree-optimization/49478 (ice in expand_widen_pattern_expr with -O3)

        PR tree-optimization/49478
        * tree-vect-loop.c (vectorizable_reduction): Handle DOT_PROD_EXPR
        with constant operand.

From-SVN: r175255

gcc/ChangeLog

+2011-06-21  Ira Rosen  <ira.rosen@linaro.org>
+
+	PR tree-optimization/49478
+	* tree-vect-loop.c (vectorizable_reduction): Handle DOT_PROD_EXPR
+	with constant operand.
+
 2011-06-21  Richard Guenther  <rguenther@suse.de>
 
 	* ipa-inline-transform.c (inline_transform): Fix typo.

gcc/testsuite/ChangeLog

+2011-06-21  Ira Rosen  <ira.rosen@linaro.org>
+
+	PR tree-optimization/49478
+	* gcc.dg/vect/pr49478.c
+
 2011-06-21  Richard Guenther  <rguenther@suse.de>
 
 	PR tree-optimization/49483

gcc/testsuite/gcc.dg/vect/pr49478.c

+/* { dg-do compile } */
+/* { dg-require-effective-target vect_int } */
+
+#include <stdarg.h>
+
+#define N 64
+
+unsigned char X[N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__))) = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63};
+
+unsigned int
+foo (int len) {
+  int i;
+  unsigned int result = 0;
+  unsigned short prod;
+
+  for (i=0; i<len; i++) {
+    prod = X[i] * 15;
+    result += prod;
+  }
+  return result;
+}
+
+/* { dg-final { cleanup-tree-dump "vect" } } */
+

gcc/tree-vect-loop.c

@@ -4591,6 +4591,25 @@ vectorizable_reduction (gimple stmt, gimple_stmt_iterator *gsi,
       return false;
     }
 
+  /* In case of widenning multiplication by a constant, we update the type
+     of the constant to be the type of the other operand.  We check that the
+     constant fits the type in the pattern recognition pass.  */
+  if (code == DOT_PROD_EXPR
+      && !types_compatible_p (TREE_TYPE (ops[0]), TREE_TYPE (ops[1])))
+    {
+      if (TREE_CODE (ops[0]) == INTEGER_CST)
+        ops[0] = fold_convert (TREE_TYPE (ops[1]), ops[0]);
+      else if (TREE_CODE (ops[1]) == INTEGER_CST)
+        ops[1] = fold_convert (TREE_TYPE (ops[0]), ops[1]);
+      else
+        {
+          if (vect_print_dump_info (REPORT_DETAILS))
+            fprintf (vect_dump, "invalid types in dot-prod");
+
+          return false;
+        }
+    }
+
   if (!vec_stmt) /* transformation not required.  */
     {
       if (!vect_model_reduction_cost (stmt_info, epilog_reduc_code, ncopies))