[llvm-commits] CVS: llvm/lib/Transforms/Scalar/InstructionCombining.cpp

[Reid Spencer]

On Sun, 2007-03-25 at 12:25 -0700, Chris Lattner wrote:
> >
> >>> +/// SubOne - Subtract one from a ConstantInt
> >>>  static ConstantInt *SubOne(ConstantInt *C) {
> >>
> >> Shouldn't these use ++/-- on APInt?  That seems more efficient.
> >
> > I should really have these functions declare the parameter  
> > constant. We
> > don't want to increment the APInt inside C. Either way, a copy of the
> > value is being made.
> 
> Right.  ConstantInt's are immutable, so it doesn't really need to be  
> marked const.  I'm saying that the implementation of these methods  
> shouldn't build a "1" apint, then add it.  Instead, it should just  
> increment an apint with ++.

Yup. I've already changed it to:

static ConstantInt *AddOne(ConstantInt *C) {
  APInt Val(C->getValue());
  return ConstantInt::get(++Val);
}

Reid.

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