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

[Reid Spencer]

On Mon, 2006-12-18 at 08:56 -0800, Chris Lattner wrote:
> On Dec 18, 2006, at 12:16 AM, Reid Spencer wrote:
> 
> >
> > Convert the last use of two-argument ConstantExpr::getCast into  
> > another
> > form so we can remove that method from ConstantExpr.
> > ---
> > Diffs of the changes:  (+3 -1)
> >
> >  ExprTypeConvert.cpp |    4 +++-
> >  1 files changed, 3 insertions(+), 1 deletion(-)
> >
> >
> > Index: llvm/lib/Transforms/ExprTypeConvert.cpp
> > diff -u llvm/lib/Transforms/ExprTypeConvert.cpp:1.115 llvm/lib/ 
> > Transforms/ExprTypeConvert.cpp:1.116
> > --- llvm/lib/Transforms/ExprTypeConvert.cpp:1.115	Wed Dec  6  
> > 19:30:31 2006
> > +++ llvm/lib/Transforms/ExprTypeConvert.cpp	Mon Dec 18 02:16:27 2006
> > @@ -210,7 +210,9 @@
> >      Constant *CPV = cast<Constant>(V);
> >      // Constants are converted by constant folding the cast that  
> > is required.
> >      // We assume here that all casts are implemented for constant  
> > prop.
> > -    Value *Result = ConstantExpr::getCast(CPV, Ty);
> > +    Instruction::CastOps opcode = CastInst::getCastOpcode(CPV,
> > +        CPV->getType()->isSigned(), Ty, Ty->isSigned());
> > +    Value *Result = ConstantExpr::getCast(opcode, CPV, Ty);
> >      // Add the instruction to the expression map
> >      //VMC.ExprMap[V] = Result;
> >      return Result;
> 
> How is this safe?  Do you know that signedness can be trusted here?

I know it is safe because all I have done is replaced getCast call with
its contents. There can't be any functional change as this is what it
was doing before. What's different is that we've moved the calls to
isSigned() out to this file instead of burying them into VMCore. I'll
revisit this when it is time to remove isSigned().

> 
> -Chris
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