PR optimization/6631

	* Makefile.in (function.o): Depend on langhooks.h.
	* alias.c (objects_must_conflict_p): Check honor_readonly when
	examining TYPE_READONLY.
	* function.c (assign_stack_temp_for_type): Likewise.

	PR optimization/6631
	* g++.dg/opt/const2.C: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@58136 138bc75d-0d04-0410-961f-82ee72b054a4

5 files changed, 57 insertions, 4 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2064e1d9e65..2513b47cdbb 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2002-10-14  Mark Mitchell  <mark@codesourcery.com>
+
+	PR optimization/6631
+	* alias.c (objects_must_conflict_p): Check honor_readonly when
+	examining TYPE_READONLY.
+	* function.c (assign_stack_temp_for_type): Likewise.
+
 2002-10-14  Falk Hueffner  <falk.hueffner@student.uni-tuebingen.de>
 
 	* config/alpha/alpha.md (extendsidi2_nofix, extendsidi2_fix):
diff --git a/gcc/alias.c b/gcc/alias.c
index 914b1532e5d..ca560b69e8c 100644
--- a/gcc/alias.c
+++ b/gcc/alias.c
@@ -1,5 +1,5 @@
 /* Alias analysis for GNU C
-   Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
+   Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
    Contributed by John Carr (jfc@mit.edu).
 
 This file is part of GCC.
@@ -332,8 +332,8 @@ objects_must_conflict_p (t1, t2)
      then they may not conflict.  */
   if ((t1 != 0 && readonly_fields_p (t1))
       || (t2 != 0 && readonly_fields_p (t2))
-      || (t1 != 0 && TYPE_READONLY (t1))
-      || (t2 != 0 && TYPE_READONLY (t2)))
+      || (t1 != 0 && lang_hooks.honor_readonly && TYPE_READONLY (t1))
+      || (t2 != 0 && lang_hooks.honor_readonly && TYPE_READONLY (t2)))
     return 0;
 
   /* If they are the same type, they must conflict.  */
diff --git a/gcc/function.c b/gcc/function.c
index 479ecef4141..0c066ed0358 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -798,7 +798,8 @@ assign_stack_temp_for_type (mode, size, keep, type)
   /* If a type is specified, set the relevant flags.  */
   if (type != 0)
     {
-      RTX_UNCHANGING_P (slot) = TYPE_READONLY (type);
+      RTX_UNCHANGING_P (slot) = (lang_hooks.honor_readonly 
+				 && TYPE_READONLY (type));
       MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
       MEM_SET_IN_STRUCT_P (slot, AGGREGATE_TYPE_P (type));
     }
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 5b1374cc043..b368a720205 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,10 @@
 2002-10-14  Mark Mitchell  <mark@codesourcery.com>
 
+	PR optimization/6631
+	* g++.dg/opt/const2.C: New test.
+
+2002-10-14  Mark Mitchell  <mark@codesourcery.com>
+
 	PR c++/7176
 	* g++.dg/parse/friend1.C: New test.
 	* g++.old-deja/g++.pt/memtemp64.C: Adjust.
diff --git a/gcc/testsuite/g++.dg/opt/const2.C b/gcc/testsuite/g++.dg/opt/const2.C
new file mode 100644
index 00000000000..9ddc5e13764
--- /dev/null
+++ b/gcc/testsuite/g++.dg/opt/const2.C
@@ -0,0 +1,40 @@
+// { dg-do run }
+// { dg-options "-O" }
+
+extern "C" void abort (void);
+
+struct QSize
+{
+  QSize();
+  QSize( int w, int h );
+  int wd, ht;
+  friend inline const QSize operator+( const QSize &, const QSize & );
+};
+
+inline QSize::QSize()
+{ wd = ht = -1; }
+
+inline QSize::QSize( int w, int h )
+{ wd = w; ht = h; }
+
+inline const QSize operator+( const QSize & s1, const QSize & s2 )
+{ return QSize(s1.wd+s2.wd, s1.ht+s2.ht); }
+
+QSize minimumSize()
+{
+  return QSize (100, 200);
+}
+
+QSize totalMinimumSize()
+{
+    QSize s = minimumSize();
+    return s + QSize( 0, 0 );
+}
+
+int main()
+{
+  QSize s = totalMinimumSize();
+  if (s.wd != 100 || s.ht != 200)
+    abort ();
+}
+