From 198fe1bfebf81e2a13b223bedcb41ed34d426862 Mon Sep 17 00:00:00 2001
From: Jakub Jelinek <jakub@redhat.com>
Date: Mon, 13 May 2013 09:50:38 +0200
Subject: [PATCH] re PR tree-optimization/57230 (tree-ssa-strlen incorrectly
 optimizes a strlen to 0)

	PR tree-optimization/57230
	* tree-ssa-strlen.c (handle_char_store): Record length for
	array store from STRING_CST.

	* gcc.dg/strlenopt-24.c: New test.

From-SVN: r198815
---
 gcc/ChangeLog                       |  4 ++++
 gcc/testsuite/ChangeLog             |  3 +++
 gcc/testsuite/gcc.dg/strlenopt-24.c | 17 +++++++++++++++++
 gcc/tree-ssa-strlen.c               | 19 +++++++++++++++++++
 4 files changed, 43 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/strlenopt-24.c

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2d1bbeaeb3a..1f6e5c2b657 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,9 @@
 2013-05-13  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/57230
+	* tree-ssa-strlen.c (handle_char_store): Record length for
+	array store from STRING_CST.
+
 	PR tree-optimization/57230
 	* tree-ssa-strlen.c (handle_char_store): Add missing integer_zerop
 	check.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 52ccf1a2653..e465f2a4c86 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2013-05-13  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/57230
+	* gcc.dg/strlenopt-24.c: New test.
+
 	PR tree-optimization/57230
 	* gcc.dg/strlenopt-23.c: New test.
 
diff --git a/gcc/testsuite/gcc.dg/strlenopt-24.c b/gcc/testsuite/gcc.dg/strlenopt-24.c
new file mode 100644
index 00000000000..962e04fded3
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/strlenopt-24.c
@@ -0,0 +1,17 @@
+/* PR tree-optimization/57230 */
+/* { dg-do run } */
+/* { dg-options "-O2 -fdump-tree-strlen" } */
+
+#include "strlenopt.h"
+
+int
+main ()
+{
+  char p[] = "hello world";
+  if (strlen (p) != 11)
+    abort ();
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump-times "strlen \\(" 0 "strlen" } } *
+/* { dg-final { cleanup-tree-dump "strlen" } } */
diff --git a/gcc/tree-ssa-strlen.c b/gcc/tree-ssa-strlen.c
index 4b6cfda5db2..5ab37645ec6 100644
--- a/gcc/tree-ssa-strlen.c
+++ b/gcc/tree-ssa-strlen.c
@@ -1740,6 +1740,25 @@ handle_char_store (gimple_stmt_iterator *gsi)
       if (si != NULL)
 	si->writable = true;
     }
+  else if (idx == 0
+	   && TREE_CODE (gimple_assign_rhs1 (stmt)) == STRING_CST
+	   && ssaname == NULL_TREE
+	   && TREE_CODE (TREE_TYPE (lhs)) == ARRAY_TYPE)
+    {
+      size_t l = strlen (TREE_STRING_POINTER (gimple_assign_rhs1 (stmt)));
+      HOST_WIDE_INT a = int_size_in_bytes (TREE_TYPE (lhs));
+      if (a > 0 && (unsigned HOST_WIDE_INT) a > l)
+	{
+	  int idx = new_addr_stridx (lhs);
+	  if (idx != 0)
+	    {
+	      si = new_strinfo (build_fold_addr_expr (lhs), idx,
+				build_int_cst (size_type_node, l));
+	      set_strinfo (idx, si);
+	      si->dont_invalidate = true;
+	    }
+	}
+    }
 
   if (si != NULL && initializer_zerop (gimple_assign_rhs1 (stmt)))
     {
-- 
2.30.2