On 2011/11/2 11:47 PM, Bernd Schmidt wrote:
> On 10/31/11 10:11, Eric Botcazou wrote:
>>> I'm suggesting a new patch, as attached. Before reload_completed, we
>>> directly return 0 upon nlabel == NULL, which should be identical with
>>> old behavior, while asserting fail if after reload (where we assume the
>>> simple_return/return distinction is required).
>>>
>>> This should ensure better that, if a post-prologue case of redirecting
>>> to the exit block ever happens we will more easily know (by some future
>>> PR :P)
>>>
>>> Bootstrapped and tested on i686, and cross tested on ARM using QEMU.
>>> Eric, is this approach okay?
>>
>> Don't you want epilogue_completed instead of reload_completed? Otherwise,
>> yes, the approach is fine with me, but wait for Bernd's input.
>
> That looks good to me too.
>
>
> Bernd
(returning to this...)
I've re-tested using epilogue_completed to be sure, everything's clean
as expected. Just applied, attaching committed patch.
Thanks,
Chung-Lin
Index: ChangeLog
===================================================================
--- ChangeLog (revision 181662)
+++ ChangeLog (working copy)
@@ -1,3 +1,9 @@
+2011-11-23 Chung-Lin Tang <clt...@codesourcery.com>
+
+ PR rtl-optimization/50496
+ * jump.c (redirect_jump): Assert fail on nlabel == NULL_RTX
+ only after epilogue is created. Add comments.
+
2011-11-22 Richard Henderson <r...@redhat.com>
* config/ia64/ia64.c (ia64_expand_atomic_op): Add model parameter.
Index: jump.c
===================================================================
--- jump.c (revision 181662)
+++ jump.c (working copy)
@@ -1495,8 +1495,19 @@
{
rtx olabel = JUMP_LABEL (jump);
- gcc_assert (nlabel != NULL_RTX);
+ if (!nlabel)
+ {
+ /* If there is no label, we are asked to redirect to the EXIT block.
+ When before the epilogue is emitted, return/simple_return cannot be
+ created so we return 0 immediately. After the epilogue is emitted,
+ we always expect a label, either a non-null label, or a
+ return/simple_return RTX. */
+ if (!epilogue_completed)
+ return 0;
+ gcc_unreachable ();
+ }
+
if (nlabel == olabel)
return 1;
