From: Richard Biener <rguenther@suse.de>
Date: Thu, 7 Nov 2019 11:49:09 +0000 (+0000)
Subject: re PR tree-optimization/92405 (ICE in vect_get_vec_def_for_stmt_copy, at tree-vect... 
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=084d390246c2172853f9e12ce04aef23cba79590;p=gcc.git

re PR tree-optimization/92405 (ICE in vect_get_vec_def_for_stmt_copy, at tree-vect-stmts.c:1683)

2019-11-07  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/92405
	* tree-vect-loop.c (vectorizable_reduction): Appropriately
	restrict lane-reducing ops to single stmt chains.

From-SVN: r277921
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 4f5662dde25..55532cc5236 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2019-11-07  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/92405
+	* tree-vect-loop.c (vectorizable_reduction): Appropriately
+	restrict lane-reducing ops to single stmt chains.
+
 2019-11-07  Martin Jambor  <mjambor@suse.cz>
 
 	PR lto/70929
diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index 788cc8786ae..dfa087ebb2c 100644
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -5865,6 +5865,18 @@ vectorizable_reduction (stmt_vec_info stmt_info, slp_tree slp_node,
       reduc_chain_length++;
     }
 
+  /* For lane-reducing ops we're reducing the number of reduction PHIs
+     which means the only use of that may be in the lane-reducing operation.  */
+  if (lane_reduc_code_p
+      && reduc_chain_length != 1
+      && !only_slp_reduc_chain)
+    {
+      if (dump_enabled_p ())
+	dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+			 "lane-reducing reduction with extra stmts.\n");
+      return false;
+    }
+
   reduc_def = PHI_RESULT (reduc_def_phi);
   for (i = 0; i < op_type; i++)
     {