llvm dev - May 2010 - [LLVMdev] [llvm-commits] [llvm] r104737 - /llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp

Hello-

Shouldn't this catch swapcontext as well?

Alistair

On 26 May 2010, at 22:14, Dale Johannesen wrote:
> 
> On May 26, 2010, at 2:05 PMPDT, Dan Gohman wrote:
> 
>> vfork and getcontext have wildly platform-dependent semantics.  
>> Handling
>> them conservatively is reasonable, even if some platforms don't
need
>> it.
>> 
>> Dan
> 
> Agreed.  Also, the performance of  code in the area of a vfork call is  
> not going to be critical.
> 
>> On May 26, 2010, at 1:48 PM, Evan Cheng wrote:
>> 
>>> Definitely not vfork. That's unnecessary. gcc is mistaken, we  
>>> shouldn't follow it. Also, getcontext is such a generic name.
It's
>>> a really bad idea to look for it.
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> llvm-commits mailing list
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I didn't see swapcontext in the list in gcc's special_function_p
function...

-bw

On May 26, 2010, at 2:20 PM, Alistair Lynn wrote:
> Hello-
> 
> Shouldn't this catch swapcontext as well?
> 
> Alistair
> 
> On 26 May 2010, at 22:14, Dale Johannesen wrote:
> 
>> 
>> On May 26, 2010, at 2:05 PMPDT, Dan Gohman wrote:
>> 
>>> vfork and getcontext have wildly platform-dependent semantics.  
>>> Handling
>>> them conservatively is reasonable, even if some platforms don't
need
>>> it.
>>> 
>>> Dan
>> 
>> Agreed.  Also, the performance of  code in the area of a vfork call is
>> not going to be critical.
>> 
>>> On May 26, 2010, at 1:48 PM, Evan Cheng wrote:
>>> 
>>>> Definitely not vfork. That's unnecessary. gcc is mistaken,
we
>>>> shouldn't follow it. Also, getcontext is such a generic
name. It's
>>>> a really bad idea to look for it.
>> _______________________________________________
>> llvm-commits mailing list
>> llvm-commits at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
> 
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

Hi-

Then that, surely, is a bug in gcc? swapcontext saves the context (via
getcontext) in its first argument - there is nothing to prevent subsequently
calling setcontext on that first argument more than once, which would result in
multiple returns?

Alistair

On 26 May 2010, at 23:02, Bill Wendling wrote:
> I didn't see swapcontext in the list in gcc's special_function_p
function...
> 
> -bw
> 
> On May 26, 2010, at 2:20 PM, Alistair Lynn wrote:
> 
>> Hello-
>> 
>> Shouldn't this catch swapcontext as well?
>> 
>> Alistair
>> 
>> On 26 May 2010, at 22:14, Dale Johannesen wrote:
>> 
>>> 
>>> On May 26, 2010, at 2:05 PMPDT, Dan Gohman wrote:
>>> 
>>>> vfork and getcontext have wildly platform-dependent semantics.
>>>> Handling
>>>> them conservatively is reasonable, even if some platforms
don't need
>>>> it.
>>>> 
>>>> Dan
>>> 
>>> Agreed.  Also, the performance of  code in the area of a vfork call
is
>>> not going to be critical.
>>> 
>>>> On May 26, 2010, at 1:48 PM, Evan Cheng wrote:
>>>> 
>>>>> Definitely not vfork. That's unnecessary. gcc is
mistaken, we
>>>>> shouldn't follow it. Also, getcontext is such a generic
name. It's
>>>>> a really bad idea to look for it.
>>> _______________________________________________
>>> llvm-commits mailing list
>>> llvm-commits at cs.uiuc.edu
>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>> 
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>