On Thu, 15 Mar 2018, Bin.Cheng wrote:
> On Thu, Mar 15, 2018 at 1:07 PM, Jakub Jelinek <ja...@redhat.com> wrote:
> > On Thu, Mar 15, 2018 at 01:56:16PM +0100, Richard Biener wrote:
> >> The following fixes the C familiy gimplification langhook to not
> >> introduce tree sharing which isn't valid during gimplification.
> >> For the specific case the tree sharing is introduced by
> >> fold_binary_op_with_cond and is reached via convert () eventually
> >> folding something. I've kept folding constants here but for the
> >> rest defer folding to GIMPLE (the gimplifier already folds most
> >> generated stmts).
> >>
> >> Bootstrapped and tested on x86_64-unknown-linux-gnu, ok for trunk and
> >> branches?
> Hi,
> FYI, this causes below failure.
>
> Failures:
> gcc.target/aarch64/var_shift_mask_1.c
Ok, these look like narrowing only done via convert () and neither
fold nor gimple folding.
An alternative slightly more expensive patch is the following which
I'm now testing on x86_64-unknown-linux-gnu, the above testcase
is fixed with it (verified with a cross).
Richard.
2018-03-16 Richard Biener <rguent...@suse.de>
PR c/84873
* c-gimplify.c (c_gimplify_expr): Revert previous change. Instead
unshare the possibly folded expression.
Index: gcc/c-family/c-gimplify.c
===================================================================
--- gcc/c-family/c-gimplify.c (revision 258584)
+++ gcc/c-family/c-gimplify.c (working copy)
@@ -245,15 +245,9 @@ c_gimplify_expr (tree *expr_p, gimple_se
unsigned_type_node)
&& !types_compatible_p (TYPE_MAIN_VARIANT (TREE_TYPE
(*op1_p)),
integer_type_node))
- {
- /* ??? Do not use convert () here or fold arbitrary trees
- since folding can introduce tree sharing which is not
- allowed during gimplification. */
- if (TREE_CODE (*op1_p) == INTEGER_CST)
- *op1_p = fold_convert (unsigned_type_node, *op1_p);
- else
- *op1_p = build1 (NOP_EXPR, unsigned_type_node, *op1_p);
- }
+ /* Make sure to unshare the result, tree sharing is invalid
+ during gimplification. */
+ *op1_p = unshare_expr (convert (unsigned_type_node, *op1_p));
break;
}
> Bisected to:
>
>
> commit 676d61f64d05af5833ddd471cc99229cedbd59b4
> Author: rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4>
> Date: Thu Mar 15 13:10:24 2018 +0000
>
> 2018-03-15 Richard Biener <rguent...@suse.de>
>
> PR c/84873
> * c-gimplify.c (c_gimplify_expr): Do not fold expressions.
>
> * c-c++-common/pr84873.c: New testcase.
>
>
> git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@258556
> 138bc75d-0d04-0410-961f-82ee72b054a4
>
> I will get more information about the failure.
>
> Thanks,
> bin
> >>
> >> Thanks,
> >> Richard.
> >>
> >> 2018-03-15 Richard Biener <rguent...@suse.de>
> >>
> >> PR c/84873
> >> * c-gimplify.c (c_gimplify_expr): Do not fold expressions.
> >>
> >> * c-c++-common/pr84873.c: New testcase.
> >
> > Ok, thanks.
> >
> > Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
