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
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. */
