[Bug middle-end/20623] ICE: fold check: original tree changed by fold with --enable-checking=fold

["spop at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #17 from spop at gcc dot gnu dot org  2007-06-20 22:58 -------
Subject: Re:  ICE: fold check: original tree changed by fold with
--enable-checking=fold

Hi,

The following patch fixes a part of the reported testsuite fails.
With this patch we avoid folding the TREE_CHAIN of an SSA_NAME, that
corresponds to its SSA_NAME_DEF_STMT.

Index: gcc/fold-const.c
===================================================================
--- gcc/fold-const.c    (revision 125883)
+++ gcc/fold-const.c    (working copy)
@@ -12775,7 +12775,8 @@ recursive_label:
   fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
   if (TREE_CODE_CLASS (code) != tcc_type
       && TREE_CODE_CLASS (code) != tcc_declaration
-      && code != TREE_LIST)
+      && code != TREE_LIST
+      && code != SSA_NAME)
     fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
   switch (TREE_CODE_CLASS (code))
     {

The only fails that remain when compiling with default languages and
--enable-checking=assert,fold,gc,misc,rtl,rtlflag,runtime,tree
on i686-linux are:

gcc.c-torture/compile/20021108-1.c
gcc.c-torture/compile/920501-7.c
gcc.c-torture/compile/labels-1.c
gcc.c-torture/compile/labels-2.c
gcc.c-torture/compile/labels-3.c
gcc.c-torture/execute/comp-goto-1.c
gcc.dg/20021029-1.c
gcc.dg/pr16973.c

Okay for trunk?

Sebastian

PS: The remaining tests all fail when fold_build2 is passed an
ADDR_EXPR with a MINUS_EXPR.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20623