On Mon, Mar 27, 2017 at 4:14 PM, Richard Biener
<richard.guent...@gmail.com> wrote:
> On Mon, Mar 27, 2017 at 2:47 PM, Martin Liška <mli...@suse.cz> wrote:
>> Hello.
>>
>> As described in the PR, we can create a PHI node in einline that has no
>> argument.
>> That can cause ICE in devirtualization and should be thus handled.
>>
>> Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.
>>
>> Ready to be installed?
>
> We shouldn't ever have a PHI w/o argument.
;; basic block 14, loop depth 0
;; pred:
# SR.2_19 = PHI <>
<L4> [0.00%]:
a::~a (&g);
resx 12
;; succ: 17
the CFG has not been cleaned up here (this block is unreachable).
Hmm, I see we are called from fold_stmt. I suppose we process
statements_to_fold before removing unreachable blocks to not
walk over dead stmts... chicken-and-egg...
Still not creating that PHI should be possible.
Index: gcc/tree-inline.c
===================================================================
--- gcc/tree-inline.c (revision 246500)
+++ gcc/tree-inline.c (working copy)
@@ -2344,6 +2344,13 @@ copy_phis_for_bb (basic_block bb, copy_b
if (!virtual_operand_p (res))
{
walk_tree (&new_res, copy_tree_body_r, id, NULL);
+ if (EDGE_COUNT (new_bb->preds) == 0)
+ {
+ /* Technically we'd want a SSA_DEFAULT_DEF here... */
+ SSA_NAME_DEF_STMT (new_res) = gimple_build_nop ();
+ }
+ else
+ {
new_phi = create_phi_node (new_res, new_bb);
FOR_EACH_EDGE (new_edge, ei, new_bb->preds)
{
@@ -2389,6 +2396,7 @@ copy_phis_for_bb (basic_block bb, copy_b
add_phi_arg (new_phi, new_arg, new_edge, locus);
}
+ }
}
}
>> Martin
