From: Richard Biener <rguenther@suse.de>
Date: Tue, 20 Oct 2015 12:34:19 +0000 (+0000)
Subject: re PR tree-optimization/68017 (ICE on valid code at -O3 with -g enabled on x86_64... 
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=d5c1a5f179880a40c6771372999d6cdefe8393fd;p=gcc.git

re PR tree-optimization/68017 (ICE on valid code at -O3 with -g enabled on x86_64-linux-gnu: cannot update SSA form)

2015-10-20  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/68017
	* tree-tailcall.c (eliminate_tail_call): Remove stmts backwards.

	* gcc.dg/torture/pr68017.c: New testcase.

From-SVN: r229073
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 45fc66ab95e..f79e71d5483 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2015-10-20  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/68017
+	* tree-tailcall.c (eliminate_tail_call): Remove stmts backwards.
+
 2015-10-20  Martin Liska  <mliska@suse.cz>
 
 	* cgraphclones.c (cgraph_node::create_virtual_clone):
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 4415ac38fe0..617ecf4d8b3 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-10-20  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/68017
+	* gcc.dg/torture/pr68017.c: New testcase.
+
 2015-10-20  Szabolcs Nagy  <szabolcs.nagy@arm.com>
 
 	PR target/66912
diff --git a/gcc/testsuite/gcc.dg/torture/pr68017.c b/gcc/testsuite/gcc.dg/torture/pr68017.c
new file mode 100644
index 00000000000..1fc219171bf
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr68017.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-g" } */
+
+long long a;
+
+short
+fn1 (short p1, unsigned short p2)
+{
+  return p1 + p2;
+}
+
+short
+fn2 ()
+{
+  int b = a ? fn1 (fn2 (), a) : 0;
+  return b;
+}
diff --git a/gcc/tree-tailcall.c b/gcc/tree-tailcall.c
index e97f6db89d8..098fff07d2f 100644
--- a/gcc/tree-tailcall.c
+++ b/gcc/tree-tailcall.c
@@ -847,17 +847,21 @@ eliminate_tail_call (struct tailcall *t)
      possibly unreachable code in other blocks is removed later in
      cfg cleanup.  */
   gsi = t->call_gsi;
-  gsi_next (&gsi);
-  while (!gsi_end_p (gsi))
+  gimple_stmt_iterator gsi2 = gsi_last_bb (gimple_bb (gsi_stmt (gsi)));
+  while (gsi_stmt (gsi2) != gsi_stmt (gsi))
     {
-      gimple *t = gsi_stmt (gsi);
+      gimple *t = gsi_stmt (gsi2);
       /* Do not remove the return statement, so that redirect_edge_and_branch
 	 sees how the block ends.  */
-      if (gimple_code (t) == GIMPLE_RETURN)
-	break;
-
-      gsi_remove (&gsi, true);
-      release_defs (t);
+      if (gimple_code (t) != GIMPLE_RETURN)
+	{
+	  gimple_stmt_iterator gsi3 = gsi2;
+	  gsi_prev (&gsi2);
+	  gsi_remove (&gsi3, true);
+	  release_defs (t);
+	}
+      else
+	gsi_prev (&gsi2);
     }
 
   /* Number of executions of function has reduced by the tailcall.  */