[llvm-commits] [llvm] r82300 - in /llvm/trunk/lib/Transforms: IPO/FunctionAttrs.cpp IPO/GlobalOpt.cpp Scalar/GVN.cpp Scalar/InstructionCombining.cpp Scalar/Reassociate.cpp Scalar/SCCP.cpp Scalar/SimplifyLibCalls.cpp Scalar/TailDuplication.cpp Utils/InlineCost.cpp

[Victor Hernandez]

Chris,
This code review got ignored while I investigated the nightly  
regressions.

>> +          // fall through
>> +        case Instruction::GetElementPtr:
>>          FlowsToReturn.insert(RVI->getOperand(0));
>>          continue;
>>        case Instruction::Select: {
>> @@ -267,6 +271,8 @@
>>        case Instruction::Malloc:
>>          break;
>>        case Instruction::Call:
>> +          if (isMalloc(RVI))
>> +            break;
>
>
> This *shouldn't* be needed.  The result of the malloc prototype  
> should already be marked NoAlias.  Please verify that this is  
> happening (likewise for calloc, valloc, memalign, etc).  If not,  
> llvm-gcc/clang and simplifylibcalls should be updated to make this  
> happen.  One bonus of this that more stuff will benefit.
>
> I see that you already modified SimplifyLibCalls.cpp to handle  
> malloc, so this can probably be removed.

Just verified that malloc prototype is being marked NoAlias.  And  
SimplifyLibCalls is marking all of those functions NoAlias also.  I  
just deleted the isMalloc() check in rev 84541.


>> = 
>> = 
>> = 
>> = 
>> = 
>> = 
>> = 
>> = 
>> = 
>> =====================================================================
>> --- llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp  
>> (original)
>> @@ -5891,9 +5893,9 @@
>>
>>  // icmp <global/alloca*/null>, <global/alloca*/null> - Global/ 
>> Stack value
>>  // addresses never equal each other!  We already know that Op0 !=  
>> Op1.
>> -  if ((isa<GlobalValue>(Op0) || isa<AllocaInst>(Op0) ||
>> +  if ((isa<GlobalValue>(Op0) || isa<AllocaInst>(Op0) || isMalloc 
>> (Op0) ||
>>       isa<ConstantPointerNull>(Op0)) &&
>> -      (isa<GlobalValue>(Op1) || isa<AllocaInst>(Op1) ||
>> +      (isa<GlobalValue>(Op1) || isa<AllocaInst>(Op1) || isMalloc 
>> (Op1) ||
>>       isa<ConstantPointerNull>(Op1)))
>
> Instead of special casing malloc here, please handle all "noalias"  
> functions the same.

I have already stopped special-casing malloc here.

Victor
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20091019/27b6a503/attachment.html>