re PR target/42894 (Invalid rtl sharing in Thumb1.)

	PR target/42894
	* varasm.c (force_const_mem): Store copy of x in desc->constant
	instead of x itself.
	* expr.c (emit_move_insn): Add a copy of y_cst instead of y_cst
	itself into REG_EQUAL note.

	* gcc.dg/tls/pr42894.c: New test.

From-SVN: r169370

gcc/ChangeLog

+2011-01-28  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/42894
+	* varasm.c (force_const_mem): Store copy of x in desc->constant
+	instead of x itself.
+	* expr.c (emit_move_insn): Add a copy of y_cst instead of y_cst
+	itself into REG_EQUAL note.
+
 2011-01-28  Joseph Myers  <joseph@codesourcery.com>
 
 	* config/freebsd.opt (posix, rdynamic): New Driver options.

gcc/expr.c

@@ -3398,7 +3398,7 @@ emit_move_insn (rtx x, rtx y)
       && (set = single_set (last_insn)) != NULL_RTX
       && SET_DEST (set) == x
       && ! rtx_equal_p (y_cst, SET_SRC (set)))
-    set_unique_reg_note (last_insn, REG_EQUAL, y_cst);
+    set_unique_reg_note (last_insn, REG_EQUAL, copy_rtx (y_cst));
 
   return last_insn;
 }

gcc/testsuite/ChangeLog

+2011-01-28  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/42894
+	* gcc.dg/tls/pr42894.c: New test.
+
 2011-01-28  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	* gcc.dg/pr47276.c: Add dg-require-visibility.

gcc/testsuite/gcc.dg/tls/pr42894.c

+/* PR target/42894 */
+/* { dg-do compile } */
+/* { dg-options "-march=armv5te -mthumb" { target arm*-*-* } } */
+/* { dg-require-effective-target tls } */
+
+extern __thread int t;
+
+void
+foo (int a)
+{
+  t = a;
+}

gcc/varasm.c

 /* Output variables, constants and external declarations, for GNU compiler.
    Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
    1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
-   2010  Free Software Foundation, Inc.
+   2010, 2011  Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -3518,7 +3518,7 @@ force_const_mem (enum machine_mode mode, rtx x)
   pool->offset &= ~ ((align / BITS_PER_UNIT) - 1);
 
   desc->next = NULL;
-  desc->constant = tmp.constant;
+  desc->constant = copy_rtx (tmp.constant);
   desc->offset = pool->offset;
   desc->hash = hash;
   desc->mode = mode;