[llvm-commits] [llvm] r50256 - /llvm/trunk/lib/Transforms/Utils/CloneFunction.cpp

[Chris Lattner]

On Apr 24, 2008, at 11:37 PM, Nate Begeman wrote:
> URL: http://llvm.org/viewvc/llvm-project?rev=50256&view=rev
> Log:
> Teach the PruningFunctionCloner how to look through loads with
> ConstantExpression GEPs pointing into constant globals.

Nice, one minor tweak:

> +
> +  if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0]))
> +    if (const LoadInst *LI = dyn_cast<LoadInst>(I))

Please change the order of the first two lines.  In theory there might  
be a zero-operand instruction in the future, and it would be nice to  
not accidentally read invalid memory.  This is definitely a  
'theoretical' concern, but good to take care of now.

Thanks Nate!

-Chris

>
> +      if (!LI->isVolatile() && CE->getOpcode() ==  
> Instruction::GetElementPtr)
> +        if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE- 
> >getOperand(0)))
> +          if (GV->isConstant() && !GV->isDeclaration())
> +            return ConstantFoldLoadThroughGEPConstantExpr(GV- 
> >getInitializer(),
> +                                                          CE);
> +
> +  return ConstantFoldInstOperands(I->getOpcode(), I->getType(),  
> &Ops[0],
> +                                  Ops.size(), TD);
> }
>
> /// CloneAndPruneFunctionInto - This works exactly like  
> CloneFunctionInto,
>
>
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