[llvm-commits] [llvm] r126445 - in /llvm/trunk: lib/Transforms/Utils/SimplifyCFG.cpp test/Transforms/SimplifyCFG/select-gep.ll

[Dan Gohman]

On Feb 24, 2011, at 3:00 PM, Frits van Bommel wrote:

> On Thu, Feb 24, 2011 at 11:46 PM, Benjamin Kramer
> <benny.kra at googlemail.com> wrote:
>> SimplifyCFG: GEPs with constant indices are cheap enough to be executed unconditionally.
>> 
>> +  case Instruction::GetElementPtr:
>> +    // GEPs are cheap if all indices are constant.
>> +    if (!cast<GetElementPtrInst>(I)->hasAllConstantIndices())
>> +      return false;
>> +    break;
>>   case Instruction::Add:
>>   case Instruction::Sub:
>>   case Instruction::And:
> 
> Since it also allows add/sub/etc., it should maybe also allow GEPs
> with one non-constant index?

A gep with one non-constant index is a multiply and an add. How
speculative are you feeling? ;-)

Dan

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