1 files changed, 77 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-u16.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-u16.c
new file mode 100644
index 00000000000..03db7e0b6a6
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-u16.c
@@ -0,0 +1,77 @@
+/* { dg-require-effective-target vect_int } */
+
+#include <stdarg.h>
+#include "tree-vect.h"
+
+#define N 64
+
+#define DOT1 43680
+#define DOT2 43680
+
+unsigned short X[N] __attribute__ ((__aligned__(16)));
+unsigned short Y[N] __attribute__ ((__aligned__(16)));
+
+/* short->short->int dot product. 
+   Not detected as a dot-product pattern.
+   Not vectorized due to presence of type-conversions. */
+unsigned int
+foo1(int len) {
+  int i;
+  unsigned int result = 0;
+  unsigned short prod;
+
+  for (i=0; i<len; i++) {
+    prod = X[i] * Y[i];
+    result += prod;
+  }
+  return result;
+}
+
+/* short->int->int dot product. 
+   Currently not detected as a dot-product pattern: the multiplication 
+   promotes the ushorts to int, and then the product is promoted to unsigned 
+   int for the addition.  Which results in an int->unsigned int cast, which 
+   since no bits are modified in the cast should be trivially vectorizable.  */
+unsigned int
+foo2(int len) {
+  int i;
+  unsigned int result = 0;
+
+  for (i=0; i<len; i++) {
+    result += (X[i] * Y[i]);
+  }
+  return result;
+}
+
+
+int main (void)
+{
+  unsigned int dot1, dot2;
+  int i;
+
+  check_vect ();
+
+  for (i=0; i<N; i++) {
+    X[i] = i;
+    Y[i] = 64-i;
+  }
+
+  dot1 = foo1 (N);
+  if (dot1 != DOT1)
+    abort ();
+
+  dot2 = foo2 (N);
+  if (dot2 != DOT2)
+    abort ();
+
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump-times "vect_recog_dot_prod_pattern: detected" 1 "vect" { xfail *-*-* } } } */
+
+/* Once the dot-product pattern is detected in the second loop, we expect
+   that loop to be vectorized on vect_udot_hi targets (targets that support 
+   dot-product of unsigned shorts).  */
+/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" { xfail *-*-* } } } */ 
+
+/* { dg-final { cleanup-tree-dump "vect" } } */