According to http://gcc.gnu.org/ml/gcc-patches/2009-11/msg00999.html
on Nov 19, 2009, Richard Guenther <richard.guent...@gmail.com> wrote:
> On Thu, Nov 19, 2009 at 4:05 AM, Alexandre Oliva <aol...@redhat.com> wrote:
>> On Nov 17, 2009, Richard Guenther <richard.guent...@gmail.com> wrote:
>>
>>>>> This looks odd. SSA DEF operand iteration should walk the PHI defs
>>>>> as well, so the change should not be necessary.
>>
>>>> I thought so, too, but by the time we get there, the operands of the PHI
>>>> stmt have already been disconnected.
>>
>>> It shouldn't be. Please try to figure out why instead.
>>
>> Gotta use a different FOR_EACH macro to handle PHI nodes.
>>
>> s/FOR_EACH_SSA_DEF_OPERAND/FOR_EACH_PHI_OR_STMT_DEF/ fixed it.
>>
>> In order to make sure no other such mistakes had been made in GCC, I
>> added an assertion check in the iterator initializer and adjusted the
>> uses of GIMPLE_PHI nodes that triggered the assertion, but that would
>> have done nothing whatsoever in its absence. I haven't looked into
>> whether doing nothing is correct.
>>
>> Should I check this in?
> I think we should rather let num_ssa_operands and delink_stmt_imm_use
> ICE on PHIs, but I'd rather do this in stage1 - can you queue this
> patch until then?
You meant 4.6 stage1, but I missed it. How's it for 4.7 stage1?
Regstrapped on x86_64-linux-gnu and i686-linux-gnu.
for gcc/ChangeLog
from Alexandre Oliva <aol...@redhat.com>
* tree-flow-inline.h (op_iter_init): Reject GIMPLE_PHI stmts.
(num_ssa_operands): Skip GIMPLE_PHI.
(delink_stmt_imm_use): Likewise.
Index: gcc/tree-flow-inline.h
===================================================================
--- gcc/tree-flow-inline.h.orig 2010-06-10 07:20:02.000000000 -0300
+++ gcc/tree-flow-inline.h 2010-06-10 15:17:51.000000000 -0300
@@ -716,9 +716,11 @@ clear_and_done_ssa_iter (ssa_op_iter *pt
static inline void
op_iter_init (ssa_op_iter *ptr, gimple stmt, int flags)
{
- /* We do not support iterating over virtual defs or uses without
+ /* PHI nodes require a different iterator initialization path. We
+ do not support iterating over virtual defs or uses without
iterating over defs or uses at the same time. */
- gcc_checking_assert ((!(flags & SSA_OP_VDEF) || (flags & SSA_OP_DEF))
+ gcc_checking_assert (gimple_code (stmt) != GIMPLE_PHI
+ && (!(flags & SSA_OP_VDEF) || (flags & SSA_OP_DEF))
&& (!(flags & SSA_OP_VUSE) || (flags & SSA_OP_USE)));
ptr->defs = (flags & (SSA_OP_DEF|SSA_OP_VDEF)) ? gimple_def_ops (stmt) : NULL;
if (!(flags & SSA_OP_VDEF)
@@ -847,8 +849,9 @@ num_ssa_operands (gimple stmt, int flags
tree t;
int num = 0;
- FOR_EACH_SSA_TREE_OPERAND (t, stmt, iter, flags)
- num++;
+ if (gimple_code (stmt) != GIMPLE_PHI)
+ FOR_EACH_SSA_TREE_OPERAND (t, stmt, iter, flags)
+ num++;
return num;
}
@@ -860,7 +863,8 @@ delink_stmt_imm_use (gimple stmt)
ssa_op_iter iter;
use_operand_p use_p;
- if (ssa_operands_active ())
+ if (ssa_operands_active ()
+ && gimple_code (stmt) != GIMPLE_PHI)
FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_ALL_USES)
delink_imm_use (use_p);
}
--
Alexandre Oliva, freedom fighter http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/ FSF Latin America board member
Free Software Evangelist Red Hat Brazil Compiler Engineer
