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Re: Problem with nested functions, aliasing, ssa rewriting, etc
- From: Richard Henderson <rth at redhat dot com>
- To: law at redhat dot com
- Cc: dnovillo at redhat dot com, gcc-patches at gcc dot gnu dot org
- Date: Wed, 10 Mar 2004 13:52:46 -0800
- Subject: Re: Problem with nested functions, aliasing, ssa rewriting, etc
- References: <200403101844.i2AIiIwJ030132@speedy.slc.redhat.com>
On Wed, Mar 10, 2004 at 11:44:18AM -0700, law@redhat.com wrote:
> CHAIN.1_2->p = &CHAIN.1->buffer;
The problem here is that this used to be "&buffer", which
had the TREE_INVARANT bit set. Failing to clear that meant
that we incorrectly treated the entire rhs as min_invariant.
Fixed thus. I'll put this through the testsuite momentarily.
Also noticed a problem in note_addressable where we'd consider
&x->y
to address X, when this is in fact a normal use. Any use of
get_base_decl should be viewed with suspicion...
r~
* tree-nested.c (convert_nonlocal_reference): Clear TREE_INVARIANT
on modified ADDR_EXPRs.
* tree-ssa-operands.c (note_addressable): Use get_base_address.
Index: tree-nested.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/Attic/tree-nested.c,v
retrieving revision 1.1.2.2
diff -c -p -d -u -r1.1.2.2 tree-nested.c
--- tree-nested.c 16 Feb 2004 15:29:55 -0000 1.1.2.2
+++ tree-nested.c 10 Mar 2004 21:47:48 -0000
@@ -763,11 +763,18 @@ convert_nonlocal_reference (tree *tp, in
walk_tree (&TREE_OPERAND (t, 0), convert_nonlocal_reference, wi, NULL);
wi->val_only = save_val_only;
- /* If the callback converted the address argument in a context
- where we only accept variables (and min_invariant, presumably),
- then compute the address into a temporary. */
- if (save_val_only && save_sub != TREE_OPERAND (t, 0))
- *tp = gimplify_val (wi->info, t, &wi->tsi);
+ if (save_sub != TREE_OPERAND (t, 0))
+ {
+ /* If we changed anything, then TREE_INVARIANT is be wrong,
+ since we're no longer directly referencing a decl. */
+ TREE_INVARIANT (t) = 0;
+
+ /* If the callback converted the address argument in a context
+ where we only accept variables (and min_invariant, presumably),
+ then compute the address into a temporary. */
+ if (save_val_only)
+ *tp = gimplify_val (wi->info, t, &wi->tsi);
+ }
}
break;
Index: tree-ssa-operands.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/Attic/tree-ssa-operands.c,v
retrieving revision 1.1.2.14
diff -c -p -d -u -r1.1.2.14 tree-ssa-operands.c
--- tree-ssa-operands.c 3 Mar 2004 00:59:48 -0000 1.1.2.14
+++ tree-ssa-operands.c 10 Mar 2004 21:47:48 -0000
@@ -1268,7 +1268,7 @@ add_stmt_operand (tree *var_p, tree stmt
static void
note_addressable (tree var, stmt_ann_t s_ann)
{
- var = get_base_decl (var);
+ var = get_base_address (var);
if (var && SSA_VAR_P (var))
{
if (s_ann->addresses_taken == NULL)