[llvm-commits] [llvm] r52690 - /llvm/trunk/lib/VMCore/Constants.cpp

[Dan Gohman]

On Jun 24, 2008, at 2:58 PM, Owen Anderson wrote:

> Author: resistor
> Date: Tue Jun 24 16:58:29 2008
> New Revision: 52690
>
> URL: http://llvm.org/viewvc/llvm-project?rev=52690&view=rev
> Log:
> In ConstantArray::getAsString(), we know the size of the resultant  
> string in advance so we can pre-allocate it and just fill in
> the entries.  This improves the time for the AsmPrinter on  
> InstructionCombining.cpp from 0.4248s to 0.3370s.
>
> Modified:
>    llvm/trunk/lib/VMCore/Constants.cpp
>
> Modified: llvm/trunk/lib/VMCore/Constants.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/Constants.cpp?rev=52690&r1=52689&r2=52690&view=diff
>
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> ======================================================================
> --- llvm/trunk/lib/VMCore/Constants.cpp (original)
> +++ llvm/trunk/lib/VMCore/Constants.cpp Tue Jun 24 16:58:29 2008
> @@ -1378,8 +1378,9 @@
> std::string ConstantArray::getAsString() const {
>   assert(isString() && "Not a string!");
>   std::string Result;
> +  Result.reserve(getNumOperands());

This should be resize, not reserve.

>
>   for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
> -    Result += (char)cast<ConstantInt>(getOperand(i))->getZExtValue();
> +    Result[i] = (char)cast<ConstantInt>(getOperand(i))- 
> >getZExtValue();
>   return Result;
> }


Dan