tree-optimization/96163 - fix placement issue with SLP and vectors

This avoids placing stmts beyond the vectorizer region begin which
confuses vect_stmt_dominates_stmt_p.

2020-07-13  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/96163
	* tree-vect-slp.c (vect_schedule_slp_instance): Put new stmts
	at least after region begin.

	* g++.dg/vect/pr96163.cc: New testcase.

diff --git a/gcc/testsuite/g++.dg/vect/pr96163.cc b/gcc/testsuite/g++.dg/vect/pr96163.cc
new file mode 100644 (file)
index 0000000..3bd376f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/vect/pr96163.cc
@@ -0,0 +1,146 @@
+// { dg-do compile }
+// { dg-require-effective-target c++17 }
+
+typedef double b __attribute__((__vector_size__(16)));
+b c;
+enum { d };
+namespace e {
+template <typename> struct g;
+struct h {
+  enum { i, j };
+};
+template <typename> struct aa;
+} // namespace e
+template <typename> struct k;
+template <typename> class l;
+template <typename, int = e::h::j> class ab;
+template <typename, int m, int n, int = 0, int = m, int = n> class o;
+template <typename> class ac;
+class p;
+namespace e {
+template <typename> struct q { typedef ac<o<double, 2, 1>> ae; };
+struct s {
+  template <int, typename t> void af(double *ak, t) { *(b *)ak = c; }
+};
+} // namespace e
+template <typename ad> class ab<ad, d> : public k<ad> {};
+template <typename ad> class ab<ad> : public ab<ad, d> {
+public:
+  typedef typename e::g<ad>::ag ag;
+  using ab<ad, d>::ah;
+  ag ai() {
+    long aj = 0;
+    return e::aa(ah()).ai(aj);
+  }
+  ag operator[](long) { return ai(); }
+};
+template <typename ad> class ay : public ab<ad> {
+public:
+  enum { a, al };
+};
+template <typename ad> class ac : public ay<ad> {
+public:
+  p am();
+};
+template <typename> struct k {
+  o<double, 2, 1> &ah() { return *static_cast<o<double, 2, 1> *>(this); }
+};
+namespace e {
+template <typename f> struct aa { aa(f); };
+template <typename ad> struct aa<l<ad>> {
+  typedef ad ao;
+  typedef typename ao::ag ag;
+  aa(ao &ak) : ap(ak.aq()) {}
+  ag &ai(long ak) { return ap[ak]; }
+  ag *ap;
+};
+template <typename ag, int ar, int as, int at, int au, int av>
+struct aa<o<ag, ar, as, at, au, av>> : aa<l<o<ag, ar, as>>> {
+  typedef o<ag, ar, as> aw;
+  aa(aw &ak) : aa<l<aw>>(ak) {}
+};
+template <typename ax> struct u {
+  enum { az, ba, bb };
+  static void bc(ax ak) { ak.template be<bb, d, typename ax::bf>(az, ba); }
+};
+template <typename ax> struct v {
+  static void bc(ax ak) { u<ax>::bc(ak); }
+};
+template <typename bg, typename bh> class w {
+  typedef bg bi;
+
+public:
+  typedef bg bj;
+  typedef bg bf;
+  w(bj ak, int, bh, bi x) : bk(ak), bl(x) {}
+  template <int bm, int, typename> void be(long, long) {
+    bn.template af<bm>(&bk.ai(0), 0);
+  }
+  bj bk;
+  bh bn;
+  bi bl;
+};
+template <typename bi, typename bo, typename bh> void bp(bi &ak, bo, bh bq) {
+  typedef aa<bi> bj;
+  bo br;
+  bj bs(ak);
+  typedef w<bj, bh> ax;
+  ax bd(bs, br, bq, ak);
+  v<ax>::bc(bd);
+}
+template <typename> struct bt;
+template <typename bu, typename bv, typename bw> void bx(bu &ak, bv by, bw bq) {
+  bt<bw>::bc(ak, by, bq);
+}
+template <typename> struct bt {
+  static void bc(o<double, 2, 1> &ak, int by, s bq) { bp(ak, by, bq); }
+};
+} // namespace e
+class bz {
+public:
+  template <typename an> void operator*(an);
+};
+namespace e {
+template <int ca> struct cb { double am[ca]; };
+} // namespace e
+template <int ca> class cc {
+  e::cb<ca> ap;
+
+public:
+  double *aq() { return ap.am; }
+};
+template <typename ad> class l : public e::q<ad>::ae {
+public:
+  typedef typename e::q<ad>::ae cd;
+  typedef typename e::g<ad>::ag ag;
+  cc<cd::al> ce;
+  ag *aq() { return ce.aq(); }
+  l() {}
+  template <typename an> l(an ak) { bx(this->ah(), ak, e::s()); }
+  template <typename cf, typename cg> void ch(cf, cg by) {
+    ag *z, *y;
+    { z = aq(); }
+    y = z;
+    y[0] = aq()[1] = by;
+  }
+};
+namespace e {
+template <typename ci, int m, int n, int cj, int ck, int cl>
+struct g<o<ci, m, n, cj, ck, cl>> {
+  typedef ci ag;
+};
+} // namespace e
+template <typename, int m, int n, int, int, int>
+class o : public l<o<double, m, n>> {
+public:
+  typedef l<o> cd;
+  template <typename cf, typename cg> o(cf ak, cg by) { cd::ch(ak, by); }
+  template <typename an> o(an ak) : cd(ak) {}
+};
+class p : public bz {};
+double cq;
+void cm() {
+  o<double, 2, 1> r = 0;
+  o cn = r;
+  cn.am() * o<double, 2, 1>(0, r[0] / cq).am();
+}

diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c
index b3645b0..72192b5 100644 (file)
--- a/gcc/tree-vect-slp.c
+++ b/gcc/tree-vect-slp.c
@@ -4404,18 +4404,26 @@ vect_schedule_slp_instance (vec_info *vinfo,
        else
          {
            /* For externals we have to look at all defs since their
-              insertion place is decided per vector.  */
-           unsigned j;
-           tree vdef;
-           FOR_EACH_VEC_ELT (SLP_TREE_VEC_DEFS (child), j, vdef)
-             if (TREE_CODE (vdef) == SSA_NAME
-                 && !SSA_NAME_IS_DEFAULT_DEF (vdef))
-               {
-                 gimple *vstmt = SSA_NAME_DEF_STMT (vdef);
-                 if (!last_stmt
-                     || vect_stmt_dominates_stmt_p (last_stmt, vstmt))
-                   last_stmt = vstmt;
-               }
+              insertion place is decided per vector.  But beware
+              of pre-existing vectors where we need to make sure
+              we do not insert before the region boundary.  */
+           if (SLP_TREE_SCALAR_OPS (child).is_empty ()
+               && !vinfo->lookup_def (SLP_TREE_VEC_DEFS (child)[0]))
+             last_stmt = gsi_stmt (as_a <bb_vec_info> (vinfo)->region_begin);
+           else
+             {
+               unsigned j;
+               tree vdef;
+               FOR_EACH_VEC_ELT (SLP_TREE_VEC_DEFS (child), j, vdef)
+                 if (TREE_CODE (vdef) == SSA_NAME
+                     && !SSA_NAME_IS_DEFAULT_DEF (vdef))
+                   {
+                     gimple *vstmt = SSA_NAME_DEF_STMT (vdef);
+                     if (!last_stmt
+                         || vect_stmt_dominates_stmt_p (last_stmt, vstmt))
+                       last_stmt = vstmt;
+                   }
+             }
          }
       /* This can happen when all children are pre-existing vectors or
         constants.  */