[PATCH] tree-optimization/98191 - fix BIT_INSERT_EXPR sequence vectorization

[Richard Biener]

This adds a missing check.

Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.

2020-12-08  Richard Biener  <rguent...@suse.de>

        PR tree-optimization/98191
        * tree-vect-slp.c (vect_slp_check_for_constructors): Do not
        follow a non-SSA def chain.

        * gcc.dg/torture/pr98191.c: New testcase.
---
 gcc/testsuite/gcc.dg/torture/pr98191.c | 10 ++++++++++
 gcc/tree-vect-slp.c                    |  3 ++-
 2 files changed, 12 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.dg/torture/pr98191.c

diff --git a/gcc/testsuite/gcc.dg/torture/pr98191.c 
b/gcc/testsuite/gcc.dg/torture/pr98191.c
new file mode 100644
index 00000000000..93cd27c21e1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr98191.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+
+typedef double v2df __attribute__((vector_size(2*sizeof(double))));
+
+v2df foo (double *y)
+{
+  v2df x = (v2df){ 1.0, 2.0 };
+  x[0] = *y;
+  return x;
+}
diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c
index a2757e707ff..35e783505b4 100644
--- a/gcc/tree-vect-slp.c
+++ b/gcc/tree-vect-slp.c
@@ -4243,7 +4243,8 @@ vect_slp_check_for_constructors (bb_vec_info bb_vinfo)
              def = gimple_assign_rhs1 (assign);
              do
                {
-                 if (!has_single_use (def))
+                 if (TREE_CODE (def) != SSA_NAME
+                     || !has_single_use (def))
                    break;
                  gimple *def_stmt = SSA_NAME_DEF_STMT (def);
                  unsigned this_lane;
-- 
2.26.2