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Fix PR tree-optimization/49478

Message ID BANLkTimYuAQPw+oJfUbM97QGEUuKCq-8GA@mail.gmail.com
State Accepted
Headers show

Commit Message

Ira Rosen June 21, 2011, 12:07 p.m. UTC 
Hi,

This patch adds a missing support of widening multiplication by a
constant in case of DOT_PROD_EXPR: the type of the constant operand
should be set according to the other operand.

Bootstrapped and tested on powerpc64-suse-linux.
Committed.

Ira

ChangeLog:

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

testsuite/ChangeLog:

   PR tree-optimization/49478
   * gcc.dg/vect/pr49478.c
diff mbox

Patch

Index: testsuite/gcc.dg/vect/pr49478.c
===================================================================
--- testsuite/gcc.dg/vect/pr49478.c     (revision 0)
+++ testsuite/gcc.dg/vect/pr49478.c     (revision 0)
@@ -0,0 +1,24 @@ 
+/* { 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" } } */
+
Index: tree-vect-loop.c
===================================================================
--- tree-vect-loop.c    (revision 175252)
+++ tree-vect-loop.c    (working copy)
@@ -4591,6 +4591,25 @@  vectorizable_reduction (gimple stmt, gimple_stmt_i
       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.  */