[tuples] S/390: Fix tree sharing in s390_gimplify_va_args

[Andreas Krebbel]

Hello,

the tuples branch currently doesn't bootstrap on S/390.  The problem
is a tree sharing bug in s390_gimplify_va_args.

The current code uses the same tree for the INDIRECT_REF args* on two
different LHSs in the following code piece:

  ...
  args->__overflow_arg_area = D.1235;
  <D.1225>:
  D.1236 = args->__gpr;
  D.1237 = D.1236 + 1;
  args->__gpr = D.1237;
  ...

Fixed with the attached patch.
Bootstrapped on s390x.

Ok to apply?

Bye,

-Andreas-

P.S.: I've added the tuples branch to my daily built list.


2008-07-14  Andreas Krebbel  <krebbel1@de.ibm.com>

	* config/s390/s390.c: (s390_gimplify_va_arg) Unshare the args* tree.


Index: gcc/config/s390/s390.c
===================================================================
*** gcc/config/s390/s390.c.orig	2008-06-25 17:40:44.000000000 +0200
--- gcc/config/s390/s390.c	2008-07-14 11:27:51.000000000 +0200
*************** s390_gimplify_va_arg (tree valist, tree 
*** 8495,8503 ****
    valist = build_va_arg_indirect_ref (valist);
    gpr = build3 (COMPONENT_REF, TREE_TYPE (f_gpr), valist, f_gpr, NULL_TREE);
    fpr = build3 (COMPONENT_REF, TREE_TYPE (f_fpr), valist, f_fpr, NULL_TREE);
-   ovf = build3 (COMPONENT_REF, TREE_TYPE (f_ovf), valist, f_ovf, NULL_TREE);
    sav = build3 (COMPONENT_REF, TREE_TYPE (f_sav), valist, f_sav, NULL_TREE);
  
    size = int_size_in_bytes (type);
  
    if (pass_by_reference (NULL, TYPE_MODE (type), type, false))
--- 8495,8507 ----
    valist = build_va_arg_indirect_ref (valist);
    gpr = build3 (COMPONENT_REF, TREE_TYPE (f_gpr), valist, f_gpr, NULL_TREE);
    fpr = build3 (COMPONENT_REF, TREE_TYPE (f_fpr), valist, f_fpr, NULL_TREE);
    sav = build3 (COMPONENT_REF, TREE_TYPE (f_sav), valist, f_sav, NULL_TREE);
  
+   /* The tree for args* cannot be shared between gpr/fpr and ovf since
+      both appear on a lhs.  */
+   valist = unshare_expr (valist);
+   ovf = build3 (COMPONENT_REF, TREE_TYPE (f_ovf), valist, f_ovf, NULL_TREE);
+ 
    size = int_size_in_bytes (type);
  
    if (pass_by_reference (NULL, TYPE_MODE (type), type, false))