From: Richard Guenther <rguenther@suse.de>
Date: Tue, 1 Feb 2011 11:27:04 +0000 (+0000)
Subject: re PR tree-optimization/47541 (For integer pointers, the value of ++*p  is not writte... 
X-Git-Tag: releases/gcc-4.5.3~255
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=309ab79b2a1621c6a28620ba51ab416ff55c7335;p=thirdparty%2Fgcc.git

re PR tree-optimization/47541 (For integer pointers, the value of ++*p  is not written back to memory)

2011-02-01  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/47541
	* tree-ssa-structalias.c (push_fields_onto_fieldstack): Make
	sure to have a field at offset zero.

	* g++.dg/torture/pr47541.C: New testcase.

From-SVN: r169472
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 88a718615167..27c16ea23b5c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2011-02-01  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/47541
+	* tree-ssa-structalias.c (push_fields_onto_fieldstack): Make
+	sure to have a field at offset zero.
+
 2011-01-31  Nathan Froyd  <froydnj@codesourcery.com>
 
 	Backport from mainline:
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 0579a449efad..d8707ade4b75 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2011-02-01  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/47541
+	* g++.dg/torture/pr47541.C: New testcase.
+
 2011-01-31  Nathan Froyd  <froydnj@codesourcery.com>
 
 	Backport from mainline:
diff --git a/gcc/testsuite/g++.dg/torture/pr47541.C b/gcc/testsuite/g++.dg/torture/pr47541.C
new file mode 100644
index 000000000000..350a05192979
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr47541.C
@@ -0,0 +1,27 @@
+/* { dg-do run } */
+
+struct Dummy {};
+struct RefCount : public Dummy {
+    ~RefCount(); /* Has to be non-pod.  */
+    int *a;
+    int *b;
+};
+RefCount::~RefCount(){}
+struct Wrapper : public Dummy { RefCount ref; };
+void __attribute__((noinline,noclone))
+Push(Wrapper ptr)
+{
+  *ptr.ref.b = 0;
+}
+extern "C" void abort (void);
+int main()
+{
+  int a = 1, b = 1;
+  Wrapper x;
+  x.ref.a = &a;
+  x.ref.b = &b;
+  Push(x);
+  if (b != 0)
+    abort ();
+  return 0;
+}
diff --git a/gcc/tree-ssa-structalias.c b/gcc/tree-ssa-structalias.c
index 314705ccbfd1..6716be7bdf2e 100644
--- a/gcc/tree-ssa-structalias.c
+++ b/gcc/tree-ssa-structalias.c
@@ -4309,6 +4309,17 @@ push_fields_onto_fieldstack (tree type, VEC(fieldoff_s,heap) **fieldstack,
 	    if (!VEC_empty (fieldoff_s, *fieldstack))
 	      pair = VEC_last (fieldoff_s, *fieldstack);
 
+	    if (!pair
+		&& offset + foff != 0)
+	      {
+		pair = VEC_safe_push (fieldoff_s, heap, *fieldstack, NULL);
+		pair->offset = 0;
+		pair->size = offset + foff;
+		pair->has_unknown_size = false;
+		pair->may_have_pointers = false;
+		pair->only_restrict_pointers = false;
+	      }
+
 	    if (!DECL_SIZE (field)
 		|| !host_integerp (DECL_SIZE (field), 1))
 	      has_unknown_size = true;