From: Richard Biener <rguenther@suse.de>
Date: Thu, 15 Sep 2016 07:17:45 +0000 (+0000)
Subject: re PR tree-optimization/77514 (ICE in VN_INFO_GET, at tree-ssa-sccvn.c:406 w/ -O2... 
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=d08615f28f4f12a5f633e11a460f9187a54a59af;p=gcc.git

re PR tree-optimization/77514 (ICE in VN_INFO_GET, at tree-ssa-sccvn.c:406 w/ -O2 (and above))

2016-09-15  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/77514
	* tree-ssa-pre.c (create_expression_by_pieces): Handle garbage
	only forced_stmts sequence.

	* gcc.dg/torture/pr77514.c: New testcase.

From-SVN: r240153
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 45850766d71..0c74a2caec2 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2016-09-15  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/77514
+	* tree-ssa-pre.c (create_expression_by_pieces): Handle garbage
+	only forced_stmts sequence.
+
 2016-09-15  Kugan Vivekanandarajah  <kuganv@linaro.org>
 
 	* tree-ssanames.h (FOR_EACH_SSA_NAME): New.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 023fcd484fd..623a764e339 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-09-15  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/77514
+	* gcc.dg/torture/pr77514.c: New testcase.
+
 2016-09-14  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/77549
diff --git a/gcc/testsuite/gcc.dg/torture/pr77514.c b/gcc/testsuite/gcc.dg/torture/pr77514.c
new file mode 100644
index 00000000000..464841ce364
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr77514.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+
+void
+m1 (char l0, char e8, int hw)
+{
+  char *rs = &l0;
+
+yu:
+  l0 = 1;
+  while (l0 != 0)
+    {
+      l0 = -l0;
+      l0 += (*rs ^ (l0 &= 1));
+    }
+  for (;;)
+    {
+      if (hw != 0)
+	goto yu;
+      rs = &e8;
+    }
+}
diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c
index 67a05133850..d1fe72cca3f 100644
--- a/gcc/tree-ssa-pre.c
+++ b/gcc/tree-ssa-pre.c
@@ -2879,7 +2879,21 @@ create_expression_by_pieces (basic_block block, pre_expr expr,
       gimple_seq_discard (forced_stmts);
       return folded;
     }
-
+  /* Likewise if we simplified to sth not queued for insertion.  */
+  bool found = false;
+  gsi = gsi_start (forced_stmts);
+  for (; !gsi_end_p (gsi); gsi_next (&gsi))
+    {
+      gimple *stmt = gsi_stmt (gsi);
+      tree forcedname = gimple_get_lhs (stmt);
+      if (forcedname == folded)
+	found = true;
+    }
+  if (! found)
+    {
+      gimple_seq_discard (forced_stmts);
+      return folded;
+    }
   gcc_assert (TREE_CODE (folded) == SSA_NAME);
 
   /* If we have any intermediate expressions to the value sets, add them