re PR tree-optimization/92241 (ice in vect_mark_pattern_st mts, at tree-vect-patterns...

2019-10-28  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/92241
	* tree-vect-loop.c (vect_fixup_scalar_cycles_with_patterns): When
	we failed to update the reduction index do not use the pattern
	stmts for the reduction chain.
	(vectorizable_reduction): When the reduction chain is corrupt,
	fail.
	* tree-vect-patterns.c (vect_mark_pattern_stmts): Stop when we
	fail to update the reduction chain.

	* gcc.dg/torture/pr92241.c: New testcase.

From-SVN: r277516

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index dc39bf8..9809040 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,16 @@
 2019-10-28  Richard Biener  <rguenther@suse.de>
 
+       PR tree-optimization/92241
+       * tree-vect-loop.c (vect_fixup_scalar_cycles_with_patterns): When
+       we failed to update the reduction index do not use the pattern
+       stmts for the reduction chain.
+       (vectorizable_reduction): When the reduction chain is corrupt,
+       fail.
+       * tree-vect-patterns.c (vect_mark_pattern_stmts): Stop when we
+       fail to update the reduction chain.
+
+2019-10-28  Richard Biener  <rguenther@suse.de>
+
        * tree-vect-loop.c (vect_create_epilog_for_reduction): Use
        STMT_VINFO_REDUC_IDX from the actual stmt.
        (vect_transform_reduction): Likewise.

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index c7f3af7..41dea35 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2019-10-28  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/92241
+       * gcc.dg/torture/pr92241.c: New testcase.
+
 2019-10-28  Uroš Bizjak  <ubizjak@gmail.com>
 
        PR target/92225

diff --git a/gcc/testsuite/gcc.dg/torture/pr92241.c b/gcc/testsuite/gcc.dg/torture/pr92241.c
new file mode 100644 (file)
index 0000000..331d03b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr92241.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-ftree-vectorize" } */
+
+int a, b;
+char c[2];
+void d() {
+  char e;
+  for (; b; b--) {
+    e = 0;
+    for (; e <= 1; e++)
+      a &= c[b + e] && 1;
+  }
+}

diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index 14d072b..d11a1f9 100644 (file)
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -689,13 +689,16 @@ vect_fixup_scalar_cycles_with_patterns (loop_vec_info loop_vinfo)
        stmt_vec_info next = REDUC_GROUP_NEXT_ELEMENT (first);
        while (next)
          {
-           if (! STMT_VINFO_IN_PATTERN_P (next))
+           if (! STMT_VINFO_IN_PATTERN_P (next)
+               || STMT_VINFO_REDUC_IDX (STMT_VINFO_RELATED_STMT (next)) == -1)
              break;
            next = REDUC_GROUP_NEXT_ELEMENT (next);
          }
-       /* If not all stmt in the chain are patterns try to handle
-          the chain without patterns.  */
-       if (! next)
+       /* If not all stmt in the chain are patterns or if we failed
+          to update STMT_VINFO_REDUC_IDX try to handle the chain
+          without patterns.  */
+       if (! next
+           && STMT_VINFO_REDUC_IDX (STMT_VINFO_RELATED_STMT (first)) != -1)
          {
            vect_fixup_reduc_chain (first);
            LOOP_VINFO_REDUCTION_CHAINS (loop_vinfo)[i]
@@ -5730,7 +5733,13 @@ vectorizable_reduction (stmt_vec_info stmt_info, slp_tree slp_node,
     {
       stmt_vec_info def = loop_vinfo->lookup_def (reduc_def);
       def = vect_stmt_to_vectorize (def);
-      gcc_assert (STMT_VINFO_REDUC_IDX (def) != -1);
+      if (STMT_VINFO_REDUC_IDX (def) == -1)
+       {
+         if (dump_enabled_p ())
+           dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+                            "reduction chain broken by patterns.\n");
+         return false;
+       }
       if (!REDUC_GROUP_FIRST_ELEMENT (def))
        only_slp_reduc_chain = false;
       reduc_def = gimple_op (def->stmt, 1 + STMT_VINFO_REDUC_IDX (def));

diff --git a/gcc/tree-vect-patterns.c b/gcc/tree-vect-patterns.c
index 31e9e2a..c0fdde6 100644 (file)
--- a/gcc/tree-vect-patterns.c
+++ b/gcc/tree-vect-patterns.c
@@ -5110,6 +5110,9 @@ vect_mark_pattern_stmts (stmt_vec_info orig_stmt_info, gimple *pattern_stmt,
     for (gimple_stmt_iterator si = gsi_start (def_seq);
         !gsi_end_p (si); gsi_next (&si))
       {
+       if (dump_enabled_p ())
+         dump_printf_loc (MSG_NOTE, vect_location,
+                          "extra pattern stmt: %G", gsi_stmt (si));
        stmt_vec_info pattern_stmt_info
          = vect_init_pattern_stmt (gsi_stmt (si),
                                    orig_stmt_info, pattern_vectype);
@@ -5169,10 +5172,13 @@ vect_mark_pattern_stmts (stmt_vec_info orig_stmt_info, gimple *pattern_stmt,
                found = true;
                break;
              }
-         if (found && s == pattern_stmt)
-           break;
          if (s == pattern_stmt)
-           gcc_unreachable ();
+           {
+             if (!found && dump_enabled_p ())
+               dump_printf_loc (MSG_NOTE, vect_location,
+                                "failed to update reduction index.\n");
+             break;
+           }
          if (gsi_end_p (si))
            s = pattern_stmt;
          else