===================================================================
@@ -2271,14 +2271,18 @@ vect_analyze_slp (vec_info *vinfo, unsig
{
/* Dissolve reduction chain group. */
stmt_vec_info vinfo = first_element;
+ stmt_vec_info last = NULL;
while (vinfo)
{
stmt_vec_info next = REDUC_GROUP_NEXT_ELEMENT (vinfo);
REDUC_GROUP_FIRST_ELEMENT (vinfo) = NULL;
REDUC_GROUP_NEXT_ELEMENT (vinfo) = NULL;
+ last = vinfo;
vinfo = next;
}
STMT_VINFO_DEF_TYPE (first_element) = vect_internal_def;
+ /* It can be still vectorized as part of an SLP reduction. */
+ loop_vinfo->reductions.safe_push (last);
}
}
===================================================================
@@ -0,0 +1,25 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target vect_int_mult } */
+
+int
+bar (int *x, int a, int b, int n)
+{
+ x = __builtin_assume_aligned (x, __BIGGEST_ALIGNMENT__);
+ int sum1 = 0;
+ int sum2 = 0;
+ for (int i = 0; i < n; ++i)
+ {
+ /* Reduction chain vectorization fails here because of the
+ different operations but we can still vectorize both
+ reductions as SLP reductions, saving IVs. */
+ sum1 += x[2*i] - a;
+ sum1 += x[2*i+1] * b;
+ sum2 += x[2*i] - b;
+ sum2 += x[2*i+1] * a;
+ }
+ return sum1 + sum2;
+}
+
+/* { dg-final { scan-tree-dump "Loop contains only SLP stmts" "vect" } } */
+/* { dg-final { scan-tree-dump "vectorizing stmts using SLP" "vect" } } */
+/* { dg-final { scan-tree-dump "vectorized 1 loops" "vect" } } */